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This page contains summaries of key physical activity research relating to Primary Care. Additional physical activity research can be found in the Information Centre, or in other population/setting sections on the left hand side menu.

It is divided into the following sections:

General

Health care costs

Counselling

Blood pressure

Cancer

Cardiac rehabilitation

Cardiovascular disease

Cognitive function

Depression

Diabetes

Metabolic syndrome

Obesity

Parkinson's disease

Spinal cord injury

Click on each section for further details.

General

Email consultations in healthcare: Scope and effectiveness

Car, J. and Sheikh, A. (2004). Email consultations in healthcare: scope and effectiveness. British Medical Journal, 329, 435-438.

Investigators from the Imperial College London and the University of Edinburgh looked at the extent of email consultations occurring, and measured the opinions of physicians and patients on the effectiveness of these consultations. The researchers found a considerable number of advantages to increasing the use of email, including time savings for both patient and doctor. In addition, email reduced the need for face-to-face consultations, particularly when managing long-term problems such as weight loss or diabetes. Other benefits included improved access to care for those with physical disabilities or living in remote areas, better opportunities for information sharing, and the chance of more speedy communications. Many of these advantages could potentially lead to financial savings through the more efficient use of a doctor's time.

Physical activity promotion in primary care

Eakin, E. G., Brown, W. J., Marshall, A. L., Mummery, K. and Larsen, E. (2004). Physical activity promotion in primary care. American Journal of Preventive Medicine, 27(4), 297-303.

There is a growing body of literature supporting the effectiveness of physical activity interventions that are delivered in the primary care setting although the article identifies that there are only a few studies that evaluate efforts to increase physician counselling on physical activity during routine practice. This study reports on the results of a primary care based physical activity counselling dissemination trial conducted as part of the Australian 10 000 Steps Rockhampton project. The RE-AIM framework, which includes five dimensions that address the potential for a health behaviour intervention to achieve a population health impact, was used to guide the evaluation. This dissemination study achieved a high rate of uptake amongst general practitioners, reasonable levels of implementation and a significant increase in the number of community residents counselled on physical activity. The authors suggest that the results suggest that evidence based primary care physical activity counselling protocols can be translated into routine practice. However they do highlight the effort needed to set up such a protocol. It is also suggested that more dissemination studies are needed in this area and future work should investigate methods for improving the uptake and sustained delivery of physical activity counselling in primary care.

Health care costs

Changes in physical activity and short-term changes in health care changes: A prospective cohort study of older adults

Martinson, B., Crain, L., Pronk, N., O’Connar, P. and Maciosek, M. (2003). Changes in physical activity and short-term changes in health care charges: A prospective cohort study of older adults. Preventive Medicine, 37, 319-326.

A random sample of approximately 2,400 older adults enrolled in a Minnesota health plan, were monitored over a three-year period to determine the influence of physical activity on health care charges. Results indicate that adults aged 50 and older who initiate a physically active way of life have significantly lower short-term health costs compared to those who remain inactive.

Counselling

Is physical activity counselling effective for older people? A cluster randomised, controlled trial in primary care

Kerse, N., Raina Elley, C., Robinson, E. & Arroll, B. (2005). Is physical activity counseling effective for older people? A cluster randomized, controlled trial in primary care. Journal of the American Geriatrics Society,53(11): 1951-1957.

According to the results of this randomised controlled study in New Zealand, providing older people with tailored physical activity advice in an approach called the ’Green Prescription‘ programme may be an effective way to help them increase their exercise levels. About three percent of New Zealanders each year currently receive a Green Prescription from their doctor. The authors investigated the effectiveness of physical activity counselling among 270 sedentary patients, aged 65 years or older. The study also included 117 doctors in the Waikato region of New Zealand. The intervention group were assigned to a Green Prescription physical activity intervention group, in which doctors provided individualised exercise recommendations based on age, medical condition, capability and everyday activities, and faxed those recommendations to trained exercise specialists. The participants then received follow-up telephone calls from the specialists over a three-month period, in addition to quarterly written material and newsletters. The control group were assigned to usual care from their physicians. The authors found that the participants assigned to the Green Prescription group reported spending about 40 additional minutes per week engaged in leisure time moderate and vigorous activity after the year-long follow-up, compared with those in the usual care group. The Green Prescription group also expended nearly three more kilocalories per kilogram of body weight each week than their peers. Participants in the Green Prescription intervention also showed improvements in measures of vitality and general health, and experienced fewer hospitalisations than those in the comparison group.

Counselling increases physical activity behaviour nine weeks after rehabilitation

van der Ploeg, H. P., Streppel, K. R. M., van der Beek, A. J., van der Woude, A. H. V., Vollenbroek-Hutten, M. M. R., van Harten, W. H. & van Mechelen, W. (2006). Counselling increases physical activity behaviour nine weeks after rehabilitation. British Journal of Sports Medicine, 40(3): 223-229.

This cross-sectional study aimed to determine the effects of the sport stimulation programme ‘‘rehabilitation and sports’’ (R&S) and R&S combined with the daily physical activity promotion programme ‘‘active after rehabilitation’’ (AaR) on sport participation and daily physical activity behaviour nine weeks after inpatient or outpatient rehabilitation. 918 Dutch subjects in four intervention rehabilitation centres were randomised to a group receiving R&S only (n = 315) or a group receiving R&S and AaR (n = 284). Subjects in six control rehabilitation centres (n = 603) received the usual care. Most common diagnoses were stroke, neurological disorders, and back disorders. Two sport and two daily physical activity outcomes were assessed with questionnaires 7 weeks before and 9 weeks after the end of rehabilitation. The 1st sport participation outcome measure was whether or not subjects participated in sport at that moment. The kind of sport, average number of hours spent on each sport a week, and self reported intensity were also recorded. Each sport was allocated to an intensity category using the physical activity compendium. The 2nd sport participation outcome was a total sport score expressed in kJ/kg body weight/h, which was calculated from the intensity category and average amount of time a week spent on each sport. Daily physical activity was assessed using 2 outcome measures. The 1st was whether or not the participants met the recommendation of being moderately physically active at least 5 days a week for 30 minutes a day, either continuously or intermittently in intervals of at least 5 minutes. This was measured using a stages of change questionnaire. The second outcome was the physical activity scale for individuals with physical disabilities (PASIPD). The Dutch version of the PASIPD is a 12 item, 7 day recall questionnaire which consists of questions on leisure time, household, and work related physical activities from which a total physical activity score in kJ/kg body weight/h was calculated. The main findings of this study were that the R&S programme did not have a significant effect on any of the 4 outcomes, whereas the combination of the R&S and AaR programmes improved both sport participation outcomes and one physical activity outcome, compared with the control group. Only the combination of R&S and AaR had increased sports participation and daily physical activity behaviour 9 weeks after the end of inpatient or outpatient rehabilitation.

Randomized controlled trial of physical activity counselling for older primary care patients

Pinto, B. M., Goldstein, M. G., Ashba, J., Sciamanna, C. N. & Jette, A. (2005). Randomized controlled trial of physical activity counseling for older primary care patients. American Journal Of Preventive Medicine, 29(4), 247-255.

Research has shown that regular physical activity reduces the risk for chronic diseases among older adults. Older adults are likely to be seen by primary care clinicians who can play an important role in promoting physical activity among their patients. This randomised controlled trial compared the effects of brief advice to exercise from a clinician supplemented by telephone-based counselling by health educators (extended advice) to brief advice from a clinician alone (brief advice). A total of 100 primary care patients (63.2% female, mean age 68.5 years) participated in the trial. The extended-advice intervention consisted of clinician advice plus exercise counselling via the telephone provided by health educators, and the brief advice condition consisted of clinician advice alone. Both interventions focused on promoting moderate-intensity physical activity. Self-reported physical activity, using the 7-Day Physical Activity Recall instrument and objective activity monitoring using Biotrainers were assessed at baseline, and at 3 and 6 months. Participants in the extended-advice group reported significantly greater participation in moderate-intensity physical activity than the brief-advice group at 3 months and 6 months. Objective activity monitoring also showed significantly increased physical activity among extended-advice versus brief advice participants at both time points. The results indicate that clinician advice with follow-up counselling can more effectively promote adoption of moderate-intensity physical activity among older, primary care patients, compared to brief advice alone.

Blood pressure

Accumulation of physical activity can lower blood pressure

Padilla, J., Wallace, J. P. & Park, S. (2005). Accumulation of physical activity reduces blood pressure in pre- and hypertension. Medicine and Science in Sport and Exercise, 37(8), 1264-1275.

Uncontrolled High Blood Pressure (BP) over a long duration can lead to heart attack, heart failure, kidney failure, stroke and blindness. Physical activity is often used as an adjunct treatment for High Blood Pressure. This study looks at whether lifestyle physical activity can help to reduce BP. A total of 28 people aged between 42 to 63 years participated in this study. Eight had normal blood pressure, 10 were prehypertensive and 10 had hypertension. The American College for Sports Medicine (ACSM) defines hypertension as systolic BP of 140 mmHg and over and/or diastolic BP of 90 mmHg and over. Prehypertension is classified as systolic BP of 120-139 mmHg or diastolic BP between 80-89 mmHg. BP below these is classified as normal. The participants were asked to accumulate 150 calories of physical activities, such as washing the car, yard work, house cleaning etc, during a 12-hour period. They wore accelerometers, which measured duration and intensity of activity, and automated ambulatory blood pressure monitors. Participants were monitored during both the 24-hour period when the activity occurred and during a 24-hour period that did not include the activities. Regardless of intensity, 4 hours of accumulated daily lifestyle physical activity lowered participants' blood pressure from hypertensive to prehypertensive and from prehypertensive to normal. After the physical activity, those with hypertension (systolic 140 mm Hg or greater) dropped on average 12.9 mm Hg for 8 hours. Participants with prehypertension (systolic 120-139 mm Hg) dropped on average 6 mm Hg for 6 hours. The diastolic blood pressure (DBP) of the participants was essentially normal and was not affected by the physical activity. The results show that accumulated physical activity reduces systolic BP in hypertension and prehypertension, but does not appear to be related to the energy expenditure. Accumulated physical activity can be utilized as an approach to treat prehypertension and hypertension.

Cancer

Physical activity and the prevention of cancer: a review of recent findings

Miles, L. (2007) Physical activity and the prevention of cancer: a review of recent findings. British Nutrition Foundation Nutrition Bulletin. 32:250-282

Recently more attention has been given to the potential relationship between physical activity and cancer risk. The current review updates the evidence of physical activity and cancer risk based on new findings. It includes evidence from the: International Agency for Research on Cancer (2002) Handbooks of Cancer Prevention: Weight Control and Physical Activity, seven other reviews and 38 cohort studies. These papers looked at the evidence for the relationship between physical activity and colon/colorectum, breast, pancreas, endometrium, prostate, ovary and lung cancers. The present review reported that based on new cohort studies there appears to be a decrease in colon cancer risk associated with physical activity which is stronger in men than women. There is consistency in the evidence presented for physical activity and reduced risk of colon cancer. Recent evidence also suggests a stronger link between breast cancer and physical activity in post-menopausal women compared to pre-menopausal women. Physical activity my also help reduce the risk of endometrium, lung and to a slightly lesser extent prostate cancer. Little evidence supports a reduced risk of ovarian or pancreatic cancer and physical activity.

Exercse and lymphocyte activation following chemotherapy for breast cancer

Hutnick, N. A., Williams, N. I., Kraemer, W. J., Orsega-Smith, E., Dixon, R. H., Bleznak, A. D., Mastro, A. M. (2005). Exercise and lymphocyte activation following chemotherapy for breast cancer. Medicine and Science in Sports and Exercise, 37(11): 1827-1835.

The study aimed to determine whether exercise training would increase lymphocyte activation in patients with breast cancer, following chemotherapy. The chemotherapeutic drugs that are used to treat breast cancer also target B and T lymphocytes that are critical to the adaptive immune response. All populations of lymphocytes decrease following chemotherapy and no known therapies exist to increase lymphocyte levels, however, a targeted exercise programme may provide benefits. The participants of the study consisted of patients with breast cancer. Lymphocyte activation was determined by the presence of various lymphocytes and other properties of the patients' plasma. 28 participated in a 6-month exercise programme, and 21 did not exercise during this time. Following chemotherapy at the start of the study, and 3 and 6 months later, patients underwent fitness evaluations and had blood samples taken. The exercise programme consisted of resistance training and aerobic activity at 60-75% functional capacity three times a week with a personal trainer. The exercising patients showed increases in maximal oxygen uptake and upper body strength. This group also showed a greater percentage of activated lymphocyte cells. Therefore, this study shows that exercise may improve immune function by increasing lymphocyte activation in patients with breast cancer following treatment.

Physical activity levels among breast cancer survivors

Irwin, M. L., McTiernan, A., Bernstein, L., Gilliland, F. D., Baumgartner, R., Baumgartner, K. and Ballard-Barbash, R. (2004). Physical activity levels among breast cancer survivors. Medicine and Science in Sport and Exercise, 36(9), 1484-1492.

This study looks at the levels of physical activity amongst individuals who have survived breast cancer who were enrolled in the Health, Eating, Activity and Lifestyle (HEAL) Study; a population-based prospective cohort study. The influence of age, obesity, stage of disease and ethnicity on various types and intensities of physical activity were also examined. Only one third of the breast cancer survivors met the recommended 150 minutes of moderate to vigorous physical activity per week. When moderate intensity household and gardening activities were included in this, 73% met the recommended levels of physical activity. Fewer obese breast cancer survivors met the guidelines than overweight or lean individuals and also fewer black breast cancer survivors met the guidelines than Hispanic and non- Hispanic white survivors. The study concludes that most of the breast cancer survivors were not meeting the physical activity recommendations proposed for the general public and therefore efforts to increase physical activity amongst this population are important. Increasing physical activity amongst this group of people would be important to decrease obesity, prevent post-diagnosis weight gain and improve breast cancer prognosis. To improve cancer treatment and survival process maintaining or increasing physical activity levels is necessary.

Recreational physical activity and the risk of breast cancer in postmenopausal women: The Women's Health Initiative Cohort Study

McTiernan, A., Kooperberg, C., White, E., Wilcox, S., Coates, R., Adams-Campbell, L., Woods, N. and Ockene, J. (2003). Recreational physical activity and the risk of breast cancer in postmenopausal women: The Women's Health Initiative Cohort Study. Journal of the American Medical Association, 290(10), 1331-1336.

The Women's Health Initiative (WHI) Cohort Study involves 74,000 postmenopausal women aged 50 to 79 years when they enrolled into this study between 1993 and 1998. Recent results show that women who performed strenuous activity at 35 years of age had a 14% decreased risk of breast cancer compared with less active women. Women who currently perform the equivalent of 1.25 to 2.5 hours of brisk walking per week also had an 18% reduction in the risk of breast cancer and those who perform the equivalent of 5 to 10 hours of brisk walking per week had a 32% reduction. These findings demonstrate that while strenuous physical activity is beneficial, other activities such as brisk walking can lead to positive health benefits.

Physical activity may protect against ovarian cancer

Pan, S. Y., Ugnat, A-M. & Mao, Y. (2005). Physical activity and the risk of ovarian cancer: A case-control study in Canada. International Journal of Cancer, 117(2), 300-307.

New research has shown that occupational and recreational physical activity may reduce the risk of ovarian cancer. A group of Canadian researchers conducted a population-based case-control study involving 442 women with ovarian cancer and 2135 control subjects between the ages of 20 and 76 years. The participants completed questionnaires on the frequency and intensity of physical activity. Women in the highest tertiles of moderate, vigorous, and total recreational activity had adjusted odds ratios for ovarian cancer of 0.67, 0.93, and 0.73, respectively, compared to those in the lowest tertile. Women with increasing levels of moderate and total recreational activity had significant trends of decreasing risk of ovarian cancer. Similar patterns were observed for premenopausal and postmenopausal women. There are several possible biologic mechanisms for the protective effect of physical activity on ovarian cancer. Physical activity may mediate the levels of endogenous sexual and metabolic hormone and growth factors. In addition, the influence of physical activity on obesity may decrease the risk of ovarian cancer. The results of this study contribute new information that adds to the existing evidence of the relationship between vigorous physical activity and ovarian cancer.

Cardiac Rehabilitation

Exercise-Based Rehabilitation for Patients with Coronary Heart Disease: Systematic Review and Meta-analysis of Randomised Controlled Trials

Taylor, R.S., Brown, A., Ebrahim, S. et al. (2004). Exericse- based rehabilitation for patients with coronary heart disease: systematic review and meta-analysis of randomised controlled trials. American Journal of Medicine, 116 (10): 682 - 692.

The purpose of this article was to review the effectiveness of exercise-based cardiac rehabilitation in patients with coronary heart disease. 48 trials with a total of 8940 patients were included in this review. Across the 29 studies that reported exercise details, patients undertook an average of 3.7 sessions of 53 minutes per week at an intensity of 76% maximum oxygen uptake.

The results showed that cardiac rehabilitation was associated with a significant reduction in all-cause mortality (odds ratio = 0.80) and total cardiac mortality (odds ratio = 0.74). Cardiac rehabilitation was also associated with reductions in modifiable risk factors. For example, significant reductions in total cholesterol, triglyceride levels and systolic blood pressure were recorded. The proportion of patients who reported smoking was also reduced significantly with cardiac rehabilitation. There were, however, no significant differences in the rates of nonfatal myocardial infarction, coronary artery bypass grafting or percutaneous coronary intervention with cardiac rehabilitation. With regards to modifiable risk factors, cardiac rehabilitation did not significantly change diastolic blood pressure or high- and low-density lipoprotein cholesterol levels.

This review concluded that the effect of cardiac rehabilitation on total mortality was independent of coronary heart disease diagnosis, type of cardiac rehabilitation, dose of exercise intervention, length of follow-up, trial quality and trial publication date. These findings are in contrast to the earlier review of Oldridge and colleagues who reported a greater reduction in all-cause death with rehabilitation trials of follow-up lasting more than 36 months. The authors have suggested that future research on this topic should examine the relative efficacy and cost of cardiac rehabilitation delivery for low - moderate risk patients in non-health care settings such as the home.

Cardiac rehabilitation after myocardial infarction in the community

Witt, B. J., Jacobsen, S. J., Weston, S. A., Killian, J. M., Meverden, R A., Allison, T. G., Reeder, G. S. and Roger, V. L. (2004). Cardiac rehabilitation after myocardial infarction in the community. Journal of the American College of Cardiology, 44(5), 988-996.

This study investigated levels of participation in cardiac rehabilitation following myocardial infarction (MI) according to age and gender. Furthermore, the authors look at the association of participation with survival. It has been reported that there are lower levels of participation in cardiac rehabilitation among women and the elderly. Among the 1821 participants studied with incident MI, 55% reported participating in cardiac rehabilitation. These individuals tended to be younger, male and have fewer comorbities. After adjustments, women were 55% less likely to participate in a programme than men, and individuals 70 years or older were 77% less likely to participate than persons younger than 60. This community-based cohort displayed differences in participation; women and older adults were less likely to participate in cardiac rehabilitation independent of other measurable characteristics. Participation in rehabilitation was independently associated with decreased mortality and lower risk of recurrent MI after MI in both males and females. The results suggest that participation in cardiac rehabilitation could lead to improved survival rates among a large proportion of patients following a MI.

Cardiovascular disease

Effectsof a home walking exercise program on fuctional status and symptoms in heart failure

Corvera-Tindel, T., Doering, L., Woo, M, Khan, S., Dracup, K. (2004). Effects of a home walking exercise program on functional status and symptoms in heart failure. American Heart Journal, 147(2), 339-346.

A progressive walking exercise programme at home can decrease symptoms experienced by people with heart failure, according to results of a recently published study. Researchers looked at the benefits of such a programme lasting 12 weeks for people with heart failure comparing 42 people in an exercise group with 37 control patients. Participants were an average of 62.2 years-old. The training group exercised once a day, five days a week. Exercise duration started at 10 minutes and intensity at 40% of maximal heart rate. This progressively increased to 60 minutes and 65% maximal heart rate in the last six weeks. No major problems were seen during exercise training. At the study's end, people in the training group walked significantly longer distances in six minutes than those in the control group (1,337.1 feet versus 1,264 feet) and the exercisers' overall symptom ratings were reduced. The researchers conclude that these findings "provide support for the safety and efficacy of home-based exercise."

Valididty of pedometers for measuring exercise adherence in heart failure patients

Evangelista, L. S., Dracup, K., Erickson, V., McCarthy, W. J., Hamilton, M. A. & Fonarow, G. C. (2005) Validity of pedometers for measuring exercise adherence in heart failure patients. Journal Of Cardiac Failure 11 (5), 366-371.

Measuring adherence to exercise is important to clinicians and researchers because inadequate adherence can adversely affect the effectiveness of an exercise programme and cloud the relationship between exercise and clinical outcomes. Therefore, assessment strategies for adherence to exercise, as with assessment strategies for other outcomes, must have demonstrated validity if they are to be employed with confidence. This study was conducted to determine the validity of pedometers as a measure of exercise adherence to a home-based walking programme in heart failure patients. Exercise adherence was measured using pedometers in 38 patients (74% men) age 54.1 ± 11.7 years who participated in a 12-month home-based walking programme. A comparison of functional status, as measured by the 6-minute walk distance and peak oxygen uptake (VO2 max) at 6 months into the exercise training programme, was made between 2 groups of participants who were thought to represent adherers and non adherers: participants who demonstrated ≥10% change in pedometer scores (n=20) and those who showed no change in pedometer scores (n=18) from baseline to 6 months. Patients who showed improvements in their pedometer scores over 6 months also had better functional status at 6 months when compared with patients whose pedometers reflected minimal change in distance walked. Pedometers are inexpensive and readily available to both clinicians and researchers. The results of this study suggest that they may be a valid indicator of exercise adherence in heart failure patients who participate in a home-based walking programme.

Exercise, body mass index, caloric intake and cardiovascular mortality

Fang, J., Wylie-Rosett, J., Cohen, H., Kaplan, R. and Alderman, M. (2003). Exercise, body mass index, caloric intake, and cardiovascular mortality. American Journal of Preventive Medicine, (25)4, 283-289.

Data from a 17-year epidemiological follow-up of the first NHANES survey was examined to determine the relationship of caloric intake, body mass index, and physical activity to CVD mortality. When BMI, physical activity,
and caloric intake were used in a single model, physical activity and obesity were each significantly related to CVD mortality, while calorie intake was not.

Effects of physical activity on life expectancy with cardiovascular disease

Franco, O. H., de Laet, C., Peeters, A., Jonker, J., Mackenbach, J. & Nusselder, W. (2005). Effects of physical activity on life expectancy with cardiovascular disease. Archives of Internal Medicine, 165(20):2355-2360.

This longitudinal study found that people aged 50 and older who engage in moderate or high levels of physical activity live longer and have less cardiovascular disease. Previous research supports the beneficial effect of physical activity in the prevention of cardiovascular disease. However, it remains unclear whether physical activity levels have a significant effect on life expectancy or on time spent with and without cardiovascular disease. The authors calculated the effects of different levels of physical activity on life expectancy and years lived with and without cardiovascular disease among people age 50 and older. They used data from the Framingham Heart Study, a cohort study that has followed 5,209 subjects over the past 46 years. The researchers calculated the effects of low, moderate, or high levels of physical activity, adjusted for age, sex, smoking, and coexistent. The study found that total life expectancy increased proportionally with higher levels of physical activity. For men aged 50 years or older, moderate and high physical activity levels led to 1.3 and 3.7 years more in total life expectancy, and 1.1 and 3.2 more years lived without cardiovascular disease, respectively, compared with those who maintained a low physical activity level. For women the differences were 1.5 and 3.5 years in total life expectancy, and 1.3 and 3.3 more years lived free of cardiovascular disease, respectively.

Physical activity, APOE genotype, and dementia risk: findings from the cardiovascular health cognition study

Podewils, L. J., Guallar, E., Kuller, L. H., Fried, L. P., Lopez, O. L., Carlson, M. and Lyketsos, C. G. (2005). Physical activity, APOE genotype, and dementia risk: findings from the cardiovascular health cognition study. American Journal of Epidemiology, 161(7), 639-651.

New research has suggested that the variety of leisure and physical activity an individual engages in, rather than the number of calories expended, may reduce dementia risk in older people. Physical activity may help preserve cognitive function and decrease dementia risk, but epidemiologic findings have been inconsistent. The authors of this research conducted a prospective study to determine the association between physical activity and risk of dementia, Alzheimer's disease, and vascular dementia. The study population comprised 3375 men and women aged 65 years or older. All were free of dementia at baseline, and all participated in the Cardiovascular Health Cognition Study between 1992 and 2000. Leisure-time energy expenditure and an activity index reflecting number of different physical activities were calculated. There were 480 incident cases of dementia over an average of 5.4 years of follow-up. After multivariate adjustment, participants in the highest quartile of physical energy expenditure had a lower relative risk of dementia compared with those in the lowest quartile, and furthermore participants engaging in more than 4 different activities had a relative risk of dementia of 0.51 compared with those engaging in 0–1 activity. A similar pattern was observed for Alzheimer's disease and vascular dementia. In summary these findings suggest that participating in a number of different activities may be as important or more important than frequency, duration, and intensity of physical activity with respect to dementia risk.

Physical activity and mortality across cardiovascular disease risk groups

Richardson, C. R., Kriska, A. M., Lantz, P. M. and Hayward, R. A. (2004). Physical activity and mortality across cardiovascular disease risk groups. Medicine and Science in Sport and Exercise, 36(11), 1923-1929.

It is well established that physical activity is a critically important behaviour and individuals who are physically active are less likely to develop chronic diseases. There is also a strong link between physical activity and mortality rates, particularly a reduction in the risk of death due to cardiovascular disease (CVD). This paper examines the extent to which the benefits of physical activity may vary by level of cardiovascular risk. Specifically, it examines the Health Retirement Study database to determine whether the mortality benefits of physical activity observed in lower CVD risk individuals can be generalised to those at a higher risk for developing CVD. In conclusion the authors found that a sedentary lifestyle is associated with a higher risk of death in pre-retirement-aged US adults. Individuals with high CVD risk appear to get the largest benefit from being physically active. They state that physical activity interventions targeting high CVD risk individuals should be a medical and public health priority.

Life-years gained from modern cardiological treatments and population risk factor changes in England and Wales, 1981–2000

Ünal, B., Critchley, J. A., Fidan, D. and Capewell, S. (2005). Life-years gained from modern cardiological treatments and population risk factor changes in England and Wales, 1981–2000. American Journal of Public Health, 95, 103-108.

This study aimed to estimate the number of life-years gained from cardiological treatments and compared this to the number of life-years gained from cardiovascular risk factor changes in England and Wales between 1981 and 2000. In 2000 there were 68230 fewer coronary deaths than in 1981. The researchers approximated that 925415 life-years were gained among people aged 25 – 84 years. Patients who benefited from cardiological treatments accounted form approximately 194145 life-years. In comparison population risk factor changes accounted for approximately 731270 life-years gained. In conclusion the researchers suggest that modest reductions in major risk factors, which can be realised through lifestyles changes such as increasing physical activity, stopping smoking and improving nutrition, led to gains in life-years 4 times higher than cardiological treatments. Therefore effective policies to promote healthy diets and physical activity may achieve the greater gains than improved treatment.

Cognitive function

Physical activity, APOE genotype, and dementia risk: findings from the cardiovascular health cognition study

Depression

Regular exercise, anxiety, depression and personality: A population-based study

De Moor, M. H., Beem, A. L., Stubbe, J. H., Boomsma, D. I. & De Geus, E. J. (2006). Regular exercise, anxiety, depression and personality: A population-based study. Preventive Medicine, 42(4): 273-279.

This cross sectional study examined whether regular exercise is associated with anxiety, depression and personality in a large population-based sample as a function of gender and age. The study sample consisted of 19,288 adolescent and adult twins and their families who participated in the study on lifestyle and health from The Netherlands Twin Registry (1991–2002). Self report questionnaires were used to assess exercise participation, anxiety, depression and personality. The findings showed that the overall prevalence of exercise participation (with a minimum of 60 min weekly at 4 METs (Metabolic Energy Expenditure Index)) in the sample was 51.4%. Exercise participation strongly declined with age from about 70% in 20 year olds to 30% in 60 year olds. Among adolescents, males exercised more, whereas, among older adults, females exercised more. Exercisers were on average less anxious, depressed and neurotic, more extraverted and were higher in dimensions of sensation seeking than non-exercisers. These differences were modest in size, but very consistent across gender and age. This study corroborates and extends previous findings and concludes that regular exercise is associated with lower neuroticism, anxiety and depression and higher extraversion and sensation seeking in this cross-section of the population.

Exercise treatment for depression

Dunn, A. L., Trivedi, M. H., Kampert, J. B., Clark, C. G. and Chambliss, H. O. (2005). Exercise treatment for depression. American Journal of Preventive Medicine, 28(1), 1-8.

This study, conducted between 1998 and 2001, was designed to test whether exercise is an efficacious treatment for mild to moderate major depressive disorder (MDD), the measure for depression was the 17-item Hamilton Rating Scale for depression (HRSD17). By the end of twelve weeks of exercise the group expending 17.5 kcal/kg/ of energy week (a dose consistent with public health recommendations) through aerobic exercise reduced mean HRSD17 by 47% from baseline. Conversely the group undertaking low dose exercise (7.0 kcal/kg/week) showed modest reductions in depressive symptoms, no better than an exercise placebo control group. The researchers found that carrying out exercise over 5 days was no more beneficial at alleviating depressive symptoms than 3 days indicating that the determining factor is total energy expenditure in a week and not how frequent you exercise. In conclusion a total energy expenditure consistent with public health recommendations but not less is effective in treating mild to moderate MDD, this amount of exercise can be obtained in 3 days or 5 days.

Diabetes

Make your diabetic patients walk. Long term impact of different amounts of physical activity on type 2 diabetes

Di Loratio, C., Fanelli, C., Lucidi, P., Murdolo, G., De Cicco, A., Parlanti, N., Ranachelli, A., Fatone, C., Taglioni, C., Santeusanio, F. and De Feo, Pierpaolo. (2005). Make your diabetic patients walk. Long term impact of different amounts of physical activity on type 2 diabetes. Diabetes Care, 28, 1295-1302.

The aim of this study was to establish the impact of different amounts of increased energy expenditure on type 2 diabetes care. The study analysed the effects of different amounts of increased energy expenditure through voluntary aerobic physical activity. One hundred and seventy nine type 2 diabetic patients were studied. Subjects were followed for 2 years and divided into 6 groups based upon their increments in energy expenditure per week measured in METs/hour/week. At baseline, the six groups did not differ for energy expenditure, age, sex or diabetes duration. After 2 years the lowest energy expenditure of 1-10METs/hour/week resulted in no significant changes in any parameter. In all other groups above 11 METs/hour/week blood pressure, total serum cholesterol, triglycerides and estimated percent of 10-year CHD risk improved. In all groups above 21 METs/hour/week body weight, waist circumference, heart rate, fasting plasma glucose, serum LDL and HDL cholesterol also improved. After 2 years the yearly costs of medication increased for the group who did no exercise, and costs decreased for individuals exercising for more than 11 METs/hour/week. In conclusion, an energy expenditure of greater than 10 METs/hour/week, obtained through aerobic leisure time physical activity is sufficient to achieve health and financial advantages. Full benefits of physical activity are achieved with an energy expenditure of greater than 21 METs/hour/week.

Physical activity reduces Type 2 diabetes risk in aging independent of body weight change

Dziura, J., Kasl, S. and Di Pietro, L. (2004). Physical activity reduces Type 2 diabetes risk in aging independent of body weight change. Journal of Physical Activity and Health, 1, 19-28.

There is little understanding as to whether physical activity can exert a protective effect on diabetes risk in older people that is independent of the changes in body weight that occur with both aging and disuse. The researchers determined the relation between current physical activity, 3 year change in body weight and the subsequent risk of Type 2 diabetes in an older cohort. This prospective study involved 2,135 older adults (³ 65 years) between 1982 and 1994. Physical activity was self reported in 1982 and 1985 with body weight and diabetes prevalence reported annually over 12 years. With adjustments for age, sex, race, education, BMI, smoking, chronic conditions, physical function and alcohol intake and inverse graded relation was observed between level of activity and rate of diabetes. This dose response was not statistically significant but older people who reported at least some activity at baseline experienced significantly lower rates of diabetes between 1983 and 1994 compared to those reporting no activity. When 3 year changes in physical activity and body weight were added to the model the relation between physical activity and reduced diabetes risk was unchanged. This suggests that physical activity may play an important role in maintaining the quality of the muscle fibres therefore helping to preserve insulin sensitivity and glucose tolerance. It has been shown that even in advanced age physical activity exerts an independent role in the prevention of Type 2 diabetes.

Physical activity, dietary intake and metabolic risk factors in non-diabetic daughters of patients with type II diabetes

Higgins, S., Gill, J. M. R., Janilionyte, R., Caslake, M. J. and Malkova, D. (2005). Physical activity, dietary intake and metabolic risk factors in non-diabetic daughters of patients with type II diabetes. Preventive Medicine, 40(2), 145-151.

The incidence of type II diabetes is increasing rapidly and this is primarily believed to be due to increases in the prevalence of inactivity and obesity. However, not all obese people develop diabetes, suggesting that while environmental factors, such as obesity, are probably necessary, they are not in themselves sufficient to precipitate this disease. First degree relatives of patients with type II diabetes have a threefold higher risk of developing diabetes than their counterparts with no family history of diabetes an indication that some individuals are genetically susceptible.
The current study compared female adult offspring of patients with type II diabetes with age and sex matched controls for daily physical activity, food intake, BMI, percentage body fat, waist circumference and metabolic risk factors for diabetes such as insulin resistance, fasting glucose and insulin concentration. The female offspring were less physically active, displayed greater adiposity, and had a less favourable metabolic profile than age and sex matched control subjects. Thus, the precipitation of metabolic dysfunction and type II diabetes is likely to be influenced not only by environmental factors but also by genetic susceptibility.

Physical activity and diabetes risk in postmenopausal women

Hsia, J., Wu, L., Allen, A., Oberman, A., Lawson,W. E., Torrens,J., Safford, M., Limacher, M. C., Howard, B. V. and Women’s Health Initiative Research Group. (2005). Physical activity and diabetes risk in postmenopausal women. American Journal of Preventive Medicine, 28(1), 19-25.

Previous research has reported an association between exercise and a reduced risk of type II diabetes mellitus in Caucasian women, what is uncertain is whether exercise reduces diabetes risk in Non-Caucasian women. The women’s Health Imitative provided an opportunity to evaluate this relationship among a diverse group of women, namely Caucasian, African-American, Hispanic, Asian, and American Indian. Participants provided information regarding their dietary habits, medical history, physical activity and anthropometric variables. During the five years of follow up subjects were asked to report the presence or absence of diabetes mellitus on an annual basis. Diabetes mellitus was by 2.2 % of Caucasian, 6.2% of African-American, 4.5% of Hispanic, 3% of Asian, and 5.7% of American Indian women. Caucasian women were the least likely ethnic group to report (28.2%) no energy expenditure from walking, and 49.4% were performing moderate or strenuous activity for over seventy minutes weekly. A strong graded inverse relationship was observed between physical activity and diabetes risk in Caucasian women. In contrast 34.5% of African-American, 34.3% of Hispanic, 43.6% of Asian women and 39.7% of American Indian women reported moderate to strenuous exercise for over seventy minutes per week. BMI adjusted hazard ratios for more active women were below those for the least active women, however no significant relationship between walking and diabetes risk was observed for African-American, Hispanic, or Asian women. These findings are consistent with several studies identifying a association between physical activity and a lower incidence of type II diabetes in Caucasian women, but raises the question of the strength of the relationship in African-American, Hispanic and Asian women, or whether the effects of physical activity may be attenuated by genetic factors in these ethic groups.

Prevention of type 2 diabetes: a review

Hussain, A., Claussen, B., Ramachandran, A. and Williams, R. (2007). Prevention of type 2 diabetes: a review. Diabetes Research and Clinical Practice, 76 (3): 317-326

Among individuals with type 2 diabetes, roughly half of their disease risk can be attributed to environmental exposure and half to genetics. This review discusses the risk factors for type 2 diabetes and identifies the most critical risk factors. The most critical risk factors identified are modifiable and the paper outlines possible interventions to reduce risk and the prevalence of type 2 diabetes across the world.

The risk factors discussed in this review are: overweight, food habits, sedentary lifestyles, size during gestational age for gestational age, diabetes during pregnancy and breastfeeding. Of these, overweight is identified as the most critical risk factor and diet and physical activity are also identified as clearly linked to diabetes risk. The authors suggest that these factors should therefore be targeted for prevention of type 2 diabetes, especially among youths. Downstream interventions, which target individuals at the highest risk of developing the condition, have the clearest evidence of benefit. Targeting patients with impaired glucose tolerance with lifestyle interventions focusing around increasing activity and altering diet have been particularly effective. The authors therefore suggest that to produce significant results, people at high risk of diabetes should be exposed to intensive and on-going interventions which focus on physical activity and a change in food habits. Although upstream interventions have the potential to impact on the whole population, it is identified that these interventions would be difficult in the sense of logistics, economy and ethical dilemma in replicating randomised controlled trials in the general population over a prolonged period of time.

Promoting and maintaining physical activity in people with type 2 diabetes

Kirk, A. F., Mutrie, N., MacIntyre, P. D. and Fisher, M. B. (2004). Promoting and maintaining physical activity in people with type 2 diabetes. American Journal of Preventive Medicine, 27(4), 289-296.

Regular physical activity has been shown to have the potential to improve the quality of life in people with type II diabetes, but limited research exists that investigates how to promote physical activity in people with type II diabetes. This study evaluated physical activity counselling over a 12 month period in people with this condition. The physical activity counselling was based upon the transtheoretical model and combined motivational theory and behavioural strategies into an individualised intervention promoting physical activity. Consultations were given at the start of the intervention and then again after 6 months, and phone calls were made at 1 and 3 months after the consultation. Changes in physical activity from baseline were measured after 12 months using a 7-day recall and accelerometry, also changes in stages and processes of exercise behaviour change. Overall, physical activity counselling appeared to be effective for promoting physical activity over a 12-month period. The authors suggest that this provides strong evidence that physical activity counselling should become part of standardised diabetes care.

Physical activity in individuals at risk for diabetes: Diabetes prevention programe

Kriska, A. M., Edelstein, S. L., Hamman, R. F., Otto, A., Bray, G. A., Mayer-Davis, E. J., Wing, R. R., Horton, E. S., Haffner, S. M. and Regensteiner, J. G. (2006). Physical activity in individuals at risk for diabetes: Diabetes prevention programme. Medicine and Science in Sports and Exercise, 38(5), 826-832.

This study assessed leisure time physical activity using questionnaires with different time frames in the Diabetes Prevention Program (DPP) cohort of 3234 overweight individuals aged >25 years with Impaired Glucose Tolerance (IGT) from 27 centres across America. Three questionnaires were used; the Modifiable Activity Questionnaire (MAQ; past year), the Low-Level Physical Activity Recall (LOPAR; past 7 days), and the Third National Health and Nutrition Examination Survey (NHANES III; past month). This allowed the relationship between the three activity measures to be examined and to compare activity levels of the DPP sample with that of a national sample with IGT. The study found that leisure time physical activity determined by the three questionnaires significantly correlated with each other, although the correlations between MAQ and NHANES III were stronger than between LOPAR and either measure. In the DPP, measures of obesity and glucose tolerance were significantly correlated with activity levels determined by MAQ and NHANES, but not LOPAR. Activity levels in DPP participants determined by the NHANES III questionnaire were generally higher than those reported by individuals meeting DPP eligibility criteria who were part of the NHANES cohort for similar age, body mass index, and race or ethnicity. In conclusion the DPP participants were more active than a national sample of individuals with IGT, this would have implications for translation when using the DPP lifestyle intervention in less active or less motivated populations. Finally, the weak relationship between activity levels obtained with MAQ and LOPAR may result from the fact that they encompass different time frames and different components of leisure activity.

The effects of 24 weeks of moderate- or high-intensity exercise on insulin resisance

O’Donovan, G., Kearney, E. M., Nevill, A. M., Woolf-May, K. & Bird, S. R. (2005). The effects of 24 weeks of moderate- or high-intensity exercise on insulin resistance. European Journal of Applied Physiology, 95(5-6): 522-528.

This randomised controlled intervention was designed to investigate the effect of exercise intensity on insulin resistance by comparing moderate- and high-intensity interventions of equal energy cost. Maximum oxygen consumption (VO2max), insulin, glucose and triglycerides were measured in 64 sedentary men before random allocation to a non-exercise control group, a moderate-intensity exercise group (three 400-kcal sessions per week at 60% of VO2max) or a high-intensity exercise group (three 400-kcal sessions per week at 80% of VO2max). An insulin sensitivity score was derived from fasting concentrations of insulin and triglycerides, and insulin resistance was assessed using the homeostasis model assessment of insulin resistance (HOMA-IR). Data were available for 36 men who finished the study. After 24 weeks, insulin concentration decreased, insulin sensitivity scores increased by and HOMA-IR decreased in the moderate- and high-intensity exercise groups. Changes were significantly greater than those observed in the control group, but were not significantly different between the exercise groups. The results suggest that exercise training is accompanied by a significant reduction in insulin resistance and that moderate-intensity exercise is as effective as high-intensity exercise when 400 kcal are expended per session.

Increasing daily walking improves glucose tolerance in overweight women

Swartz, A.M., Strath, S.J., Bassett, D.R., Moore, J.B., Redwine, B.A., Groer, M., and Thompson, D.L. (2003) Increasing daily walking improves glucose tolerance in overweight women. Preventive Medicine, 37, 356-362.

18 inactive overweight females took part in a 12-week pedometer study. During an initial 4-week control phase subjects wore pedometers, but were asked not to change their physical activity habits. For this period each participant walked on average 4,972 steps/day. Then subjects participated in an 8-week physical activity intervention period and were encouraged to take 10,000 steps/day. Throughout the activity intervention participants recorded their number of steps and any exercise performed each day. The women were also asked to not restrict calorie consumption during the physical activity intervention. Results show that participants increased their total steps/day by 85% to 9,213 during the intervention period. There were no significant decreases in body fat percentage, waist circumference, waist-to-hip ratio, or resting heart rate over the 12-week period. Despite no decreases in the previous factors, systolic and diastolic blood pressure decreased by 4.7% and 6.7%, respectively. The intervention was also effective at improving glucose intolerance by 11%, without any dietary or anthropometric changes.

Metabolic syndrome

Physical activity, dietary intake and metabolic risk factors in non diabetic daughters of patients with type II diabetes

The incidence of type II diabetes is increasing rapidly and this is primarily believed to be due to increases in the prevalence of inactivity and obesity. However, not all obese people develop diabetes, suggesting that while environmental factors, such as obesity, are probably necessary, they are not in themselves sufficient to precipitate this disease. First degree relatives of patients with type II diabetes have a threefold higher risk of developing diabetes than their counterparts with no family history of diabetes an indication that some individuals are genetically susceptible.
The current study compared female adult offspring of patients with type II diabetes with age and sex matched controls for daily physical activity, food intake, BMI, percentage body fat, waist circumference and metabolic risk factors for diabetes such as insulin resistance, fasting glucose and insulin concentration. The female offspring were less physically active, displayed greater adiposity, and had a less favourable metabolic profile than age and sex matched control subjects. Thus, the precipitation of metabolic dysfunction and type II diabetes is likely to be influenced not only byenvironmental factors but also by genetic susceptibility.

Exercise and the metabolic syndrome in older adults

Stewart, K. J., Bacher, A. C., Turner, K., Lim, J.G., Hees, P. S., Shapiro, E. P., Tayback, M. and Ouyang, P. (2005). Exercise and risk factors associated with metabolic syndrome in older adults. American Journal of Preventive Medicine, 8(1), 9-18.

Researchers found that in people aged 55 to 75 years, a moderate programme of physical exercise can significantly offset the potentially deadly mix of risk factors for heart disease and diabetes known as the metabolic syndrome. More specifically, the researchers found that exercise improved overall fitness, but the 23 percent fewer cases were more strongly linked to reductions in total and abdominal body fat and increases in muscle leanness, rather than improved fitness.

Obesity

Improvement of Fitness, Body Composition, and Insulin Sensitivity in Overweight Children in a School-Based Exercise Programme

Carrel, A. L., Clark, R. R., Peterson, S. E., Nemeth, B. A., Sullivan, J. & Allen, D. B. (2005). Improvement of Fitness, Body Composition, and Insulin Sensitivity in Overweight Children in a School-Based Exercise Program. Archives of Pediatric Adolescent Medicine, 159, 963-968.

Obesity and poor physical fitness constitute health problems affecting an increasing number of children today. Causes include an environment that facilitates increased caloric intake and reduced physical activity. Schools are regarded as a key setting for increasing physical activity levels in inactive young people. This study looked at whether a school-based fitness programme can improve body composition, cardiovascular fitness levels, and insulin sensitivity in overweight children. Fifty overweight middle school children (aged 9-14 approx.) with a body mass index (BMI) above the 95th percentile for age were chosen as the subjects for this intervention. They were randomly placed in lifestyle-focused, fitness-oriented gym classes (treatment group) or standard gym classes (control group) for 9 months. Children underwent evaluation of fasting insulin and glucose levels, body composition by means of dual energy absorptiometry, and maximum oxygen consumption (VO2 max) treadmill testing at baseline (before the school year) and at end of the school year. At baseline, there were no differences between groups before intervention. Compared with the control group, the treatment group demonstrated a significantly greater loss of body fat, greater increase in cardiovascular fitness and greater improvement in fasting insulin level. The authors concluded that children enrolled in fitness-oriented gym classes showed greater loss of body fat, increase in cardiovascular fitness, and improvement in fasting insulin levels than control subjects.

Exercise prescription for the prevention of obesity in adolescents

Carrel, A. L. and Bernhardt, D. T. (2004). Exercise prescription for the prevention of obesity in adolescents. Current Sports Medicine Reports, 3(6), 330-336.

Childhood obesity is an increasing public health problem which poses important challenges for both health care and school-centred environments. Each faces difficulties in successfully addressing this major problem. Schools report that they have a lack of training in intervention, and health care providers report ineffective office-based intervention strategies. The prevention and treatment of childhood obesity could be improved if the coordination of interventions in both the school and office is improved. Prescribing exercise to prevent a further rise in childhood obesity could be very effective. The review evaluates recent literature relating to the health care provider’s role in prescribing exercise and the associated health benefits of exercise for children. Health professionals caring for children and adolescents are in a key position to help prevent and treat obesity by promoting behavioural and environmental changes. The evidence base is insufficient to provide specific guidelines for assessment and treatment of all aspects of childhood and adolescent obesity. The paper includes a number of recommendations which reflect critical reviews of the literature and are based upon expert committee guidelines.

Fighting Fit? An evaluation of health practitioner input to improve healthy living and reduce oebsity for adults with learning disabilities

Chapman, M., Craven. M. and Chadwick, D. (2005) Fighting Fit? An evaluation of health practitioner input to improve healthy living and reduce obesity for adults with learning disabilities. Journal of Intellectual Disabilities, 9(2), 131-144.

People with learning disabilities are at high risk of obesity and consequent health risks. This study aimed to (1) describe levels of obesity for adults supported by learning disability services, and to (2) evaluate the effectiveness of health practitioner input with individuals with learning disabilities. Body mass index (BMI) was measured at 6 month intervals and change in BMI over time was compared between a non-input group and a group receiving practitioner input to improve healthy living. Initially 35 percent of the non-input sample was classified as clinically obese. Mean BMI increased over time for the non-input group at first, but decreased for the group that received practitioner input. The differences in weight change between the two groups reached statistical significance with a greater weight reduction in the input group. Implications for service provision are discussed.

Estimated change in physical activity level (PAL) and prediction of 5-year-weight change in men: The Aerobics Center Longitudinal Study

Di Pietro, L., Dziura, J. and Blair, S. N. (2004). Estimated change in physical activity level (PAL) and prediction of 5-year-weight change in men: The Aerobics Center Longitudinal Study. International Journal of Obesity, 28(12), 1541-1547.

This paper looks at the relationship between the average daily physical activity level (PAL) and the pattern of weight change in men who are at risk for weight gain. It is a clinic-based cohort study which took place over an average of 5 years. The study looked at 2501 healthy men aged between 20 and 55 years who were all participating in the Aerobic Longitudinal Study. They had all received at least 4 medical examinations between 1970 and 1998. At all four examinations daily leisure-time physical activity was reported and body weight was measured. The average daily PAL was estimated from all activities as well as from other incidental and passive activities. The results suggest that daily PAL was inversely related to weight gain in this cohort. The amount of daily energy expenditure required to maintain a healthy body weight is controversial, however the current guideline of 30 minutes or more or moderate intensity physical activity seems insufficient for reducing weight gain. The results of this study suggest that either increasing to, or maintaining a PAL at least 60% above resting metabolic rate may be necessary to maintain body weight in middle-age. This can be achieved by incorporating between 45 and 60 minutes of brisk walking or gardening or cycling into the daily routine.

Relations of moderate and vigorous physical activity to fitness and fatness in adolescents

Gutin, B., Yin, Z., Humphries, M. C. and Barbeau, P. (2005). Relations of moderate and vigorous physical activity to fitness and fatness in adolescents. American Journal of Clinical Nutrition, 81(4), 746-750.

This paper looks at the hypothesis that vigorous physical activity would be associated with better cardiovascular fitness and lower body fat to a greater degree than moderate intensity physical activity. It is a cross sectional study of 421 black and white high school students and physical activity was measured over 5 days using accelerometry. Cardiovascular fitness was assessed using a multistage fitness test and body fat measured with dual-energy x-ray absorbtiometry. The results indicated that a higher index for cardiovascular fitness was associated with higher amounts of moderate and vigorous physical activity. More variance was explained by vigorous than by moderate physical activity. A lower percentage of body fat was associated with higher amounts of vigorous physical activity but not with the moderate levels of physical activity. In conclusion the study found that adolescents who engaged in relatively large amounts of free-living vigorous exercise were likely to be relatively fit and lean.

Watching television is associated with childhood obesity: but is it clinically important?

Hancox, R.J. & Poultn, R. (2005). Watching television is associated with childhood obesity: but is it clinically important? International Journal of Obesity 30(1): 171-175.

This study examined the impact of television viewing during childhood and adolescence on body mass index (BMI) in children up to the age of 15 years. In total, 976 individuals were assessed at birth and every 2 years from the age of 3 to 15 years old. Between the ages of 5 and 11 years old parents were asked to estimate how much television their children watched and between 13 and 15 years of age the children themselves were asked to self report. Results indicated that at each age, BMI and overweight were significantly associated with the amount of television watched. Between the ages of five and 15, children were found to watch an average of 2.33 hours of television per weeknight. Aged 13 to 15 they watched an average of 24.6 per week (including weekends). At each age, the mean hours television viewing reported up to and including that age was significantly associated with BMI. These associations were stronger in girls, which was thought to be a result of lifestyle differences and physical make up. The researchers noted that although the effect size appears small, the association between television viewing and BMI is stronger than that reported for BMI, diet and physical activity.

Adiposity as compared with physical activity in predicting mortality among women

Hu, F.B. (2004). Adiposity as compared with physical activity in predicting mortality among women. New England Journal of Medicine, 351(26), 2694-2703.

Over 115,000 women aged between 30 and 55 years were followed for 24 years to examine the associations of body mass index and physical activity with death. The total number of deaths exceeded 10,000 (75% from cardiovascular disease or cancer), the researcher estimated that excess weight (defined as a body-mass index of 25 or higher) and physical inactivity (less than 3.5 hours of exercise per week) together accounted for 31 percent of all the premature deaths, 59 percent of deaths from cardiovascular disease, and 21 percent of deaths from cancer. Adiposity and alarmingly even modest weight gain during adulthood, independent of physical activity was associated with a higher risk of death. In fact mortality rates increased monotonically with higher body mass index. Importantly however higher levels of physical activity appeared to be beneficial at all levels of adiposity.

Pharmacologic and surgical management of obesity in primary care: a clinical practice guideline from the American College of Physicians

Snow, V., Barry, P., Fitterman, N., Qaseem, A, and Weiss K. (2005). Pharmacologic and surgical management of obesity in primary care: a clinical practice guideline from the American College of Physicians. Annals of Internal Medicine, 142(7), 525-531.

This article from the American College of Physicians provides suggested guidelines for the management of obesity. They recommend diet and physical activity for everyone and drugs and surgery only for obese patients who are not able to achieve weight-loss goals with diet and exercise alone. They suggest that people with a body mass index (BMI) of over 30kg.m-2 might consider drug therapy, but only once an appropriate trial of diet and exercise has failed. Surgery should only be for those patients with a BMI of over 40 kg.m-2 and who additionally have obesity-related health problems such as high blood pressure, diabetes or sleep apnoea.

Childhood Obesity: Consensus Statement

Speiser, P. W., Rudolf, M. C. J., Anhalt, H., Camacho-Hubner, c., Chiarelli, F., Eliakim, A., Freemark, M., Gruters, A., Hershkovitz, E., Iughetti, L., Krude, H., Latzer, Y., Lustig, R. H., Pescovitz, O. H., Pinhas-Hamiel, O., Rogol, A. D., Shalitin, S., Sultan, C., Stein, D., Vardi, P., Werther, G. A., Zadik, Z., Zuckerman-Levin, N. & Hochberg, Z. (2005). CONSENSUS STATEMENT: Childhood Obesity. Journal of Clinical Endocrinology & Metabolism, 90(3), 1871-1887.

This article outlines a consensus statement on childhood obesity that was agreed by a group of 65 international health professionals at a conference in 2004. In developing the consensus statement, the group examined the available evidence relating to the problem of childhood obesity and developed recommendations for future action. The article presents research evidence on the prevalence, diagnosis and causes of obesity in young people, and discusses the risks of children developing medical conditions as a result of obesity, such as diabetes, the metabolic syndrome, hyperandrogenemia, cardiovascular disease and respiratory problems. Guidance and recommendations for the prevention of obesity through a multitude of settings and life stages, such as schools, communities, during pregnancy and through government policies are summarised. Suggested ways of treating the problem through dietary, lifestyle, exercise and pharmacological intervention are also discussed.

The obesity epidemic: both energy intake and physical activity contribute

Stubbs, C. O. and Lee, A. J. (2004). The obesity epidemic: both energy intake and physical activity contribute. Medical Journal of Australia, 181(9), 489-491.

This viewpoint highlights more recent thinking on the obesity epidemic, suggesting that both energy intake and physical activity contribute. The paper looks at recent data from Australia, the United States and Europe which show that increased self-reported energy intake is associated with obesity. It highlights that this is in contrast to earlier suggestions that the obesity epidemic has occurred despite minimal or no increase in per capita energy intake from food. The effect of increased energy intake is compounded by sedentary lifestyles. It concludes by stating that both physical activity and nutrition must be addressed to reduce the prevalence of obesity and hence improve health.

Cocrane Review: Interventions for preventing obesity in children

Summerbell C. D, et al. (2005). Interventions for preventing obesity in children. The Cochrane Database of Systematic Reviews, Issue 3.

A study published in the Cochrane Database of Systematic Reviews, a publication of the United Kingdom-based health information and research group Cochrane Collaborative, found that obesity interventions that incorporate ‘fun’ physical activities and food preparation lessons are more effective than standard programmes in helping overweight children lose weight. Researchers conducted a meta-analysis of 22 international studies that tested the efficacy of physical activity and nutrition education programmes. They found that although most children who took part in short-term (12 weeks to 12 months) or long-term (at least 12 months) exercise and nutrition interventions did not lose a significant amount of weight, ‘nearly all’ of the studies found that children's physical activity levels or eating habits improved after participating in an intervention programme. The most effective interventions included ‘fun’ events, such as dance or martial arts classes, and presented healthy foods in a creative way. Study authors conclude that programmes that integrate enjoyable activities into exercise and nutrition programmes and also focus on creating a supportive ‘psycho-social’ environment are likely to be most effective in helping overweight children lose weight.

Increasing daily walking improves glucose tolerance in overweight women

Single sessions of intermittent and continuous exercise and postprandial lpemia

Thomas, A., Michaelson, J., Ball, S. and Thomas, T. (2004). Single sessions of intermittent and continuous exercise and postprandial lipemia. Medicine and Science in Sport and Exercise, 36(8), 1364-1371.

Thirty minutes of moderate exercise accumulated in intermittent, 10-minute bouts of activity can lower fat and triglyceride levels in the bloodstream after eating, a new study concludes. Interestingly, 30 minutes of continuous exercise does not have the same beneficial effect. Eighteen inactive adults with normal lipid profiles ate a high-fat meal after jogging on a treadmill in continuous and intermittent bouts. The researchers took blood samples from the participants prior to exercise and every two hours during the activity period to measure blood fats, which normally rise after food consumption. The results show that multiple sessions of 10-minute exercise bouts, if repeated throughout a day lower fats in the blood compared to no exercise or a single long bout of equal duration, intensity and caloric expenditure. The research team from the University of Missouri and SMSU believe intermittent exercise may lower blood fats due to a slight potential increase in metabolism after each short exercise bout.

Children of parents concerned about road safety are more likely to be overweight or obese

Timperio, A., Salmon, J., Telford, A. and Crawford, D. (2005). Perceptions of local neighbourhood environments and their relationship to childhood overweight and obesity. International Journal of Obesity, 29(2), 170-175.

In this cross sectional study that measured the perceptions of the local neighbourhood according to the parents of over 1000 children, it was found that among 10-12 year old children, those whose parents agreed that there was heavy traffic in their local streets were more likely to be overweight or obese. This suggests that among this age group parental perceptions of heavy traffic on local streets and concern about road safety may be indirect influences on overweight and obesity.

Parkinson's disease

Physical activity and the risk of Parkinson's disease

Chen, H., Zhang, S. M., Schwarzschild, M. A., Hernán, M. A. and Ascherio, A. (2005). Physical activity and the risk of Parkinson’s disease. Neurology, (64), 664-669.

A study examining the effect of strenuous physical activity on the risk of developing Parkinson’s disease has found that men who exercised regularly and vigorously in their adult life had a lower risk for developing Parkinson’s disease than those who did not. Men who were the most physically active at the start of the study cut their risk of developing Parkinson's disease by 50 percent compared to participants who were the least physically active. The authors also found that men who reported regularly having engaged in strenuous physical activity in early adult life cut the risk for Parkinson's by 60 percent compared to those who did not. Parkinson's disease is a progressive nervous disease that generally affects people after age 50. It destroys brain cells that produce dopamine and is characterized by muscular tremor, slowing of movement, rigidity and postural instability.

Spinal cord injury

Physical activity levels are low in free-living adults with chronic paraplegia

Buchholz, A. C., McGillivray, C. F., & Pencharz, P. B. (2003). Physical activity levels are low in free-living adults with chronic paraplegia. Obesity Research, 11(4), 563-570.

Research indicates that individuals with spinal cord injury exhibit a high prevalence of cardiovascular disease and are also highly susceptible to obesity, perhaps due to a lack of physical activity or physical activity opportunities. The physical activity levels of 27 men and women with chronic paraplegia were compared to the levels recommended by the World Health Organization. 70.4% of the study participants were obese, which was associated with low levels of physical activity, especially in the group with complete spinal cord lesions. Overall, it is recommended that individuals with paraplegia increase the frequency, duration, and/or intensity of their physical activity to limit obesity and cardiovascular disease risk factors by improving mobility and functional tasks with a combination of flexibility, strength training, and aerobic fitness.

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