CTF Structured Abstract: Physical activity counselling

Canadian Task Force on Preventive Health Care

Structured Abstract

Please note: In 2003, the CTF updated its Grades of Recommendations to include an "I Recommendation" for situations where insufficient evidence exists to allow a recommendation to be made. (Formerly, these situations were captured under a "C Recommendation".) This change is not retroactive, and all "C Recommendations" made prior to 2003 have not been reevaluated in light of the new "I" recommendation grade. For a discussion of these recommendation grades, please link to the 2003 article in the Canadian Medical Association Journal here.

Physical Activity Counselling

Adapted by Marie-Dominique Beaulieu, MD, MSc, FCFP, Associate Professor, Department of Family Medicine, University of Montreal, from materials prepared for the U.S. Preventive Services Task Force

These recommendations were finalized by the Task Force in March 1994

Objective
Burden of Suffering
Options
Outcomes

Evidence
Values
Benefits, Harms, and Costs
Recommendations

Validation
Sponsors
Selected References

Objective
To make recommendations about physical activity counselling to prevent various health conditions, particularly coronary heart disease (CHD), hypertension, obesity, non-insulin dependent diabetes mellitus (NIDDM) and osteoporosis in persons in Canada.

Burden of Suffering

Physical activity (as distinct from physical fitness) and its opposite, sedentariness, refer to behaviours generally defined in terms of the amount of time devoted to certain types of physical activity or exercise. The total burden of suffering attributable to a sedentary lifestyle in Canada and the United States is difficult to ascertain. However, sedentary lifestyle appears to be an independent risk factor for all-cause mortality and of developing certain chronic diseases, particularly, coronary heart diseases (CHD), hypertension and obesity, and has also been associated with the risk of developing non-insulin dependent diabetes mellitus (NIDDM) and osteoporosis. In 1985, a review of eight national studies conducted in Canada and the United States showed that about 20% of the adult Canadian population exercised at a level recommended for cardiopulmonary fitness, 40% exercised at a level below that recommended for cardiopulmonary fitness but sufficient for other health benefits, and 40% were sedentary.

Options

Physician counselling regarding the regular practice of moderate intensity physical activity (e.g., normal walking, golfing on foot, slow biking, raking leaves, cleaning windows, slow dancing, light restaurant work, etc.) for all individuals and regular weight-bearing exercise in women.

Outcomes

Outcomes varied by condition to be prevented and included incidence of CHD, all-cause and CHD mortality; risk for developing hypertension; obesity, weight loss, morbidity and mortality associated with obesity; risk for developing NIDDM; bone loss and hip fractures.

Evidence

These recommendations were adapted from materials prepared for the 1989 US Preventive Services Task Force. MEDLINE was searched for English-language articles published from 1988 to 1993 using the keywords "exertion", "exercise", "leisure activities", "mortality", "coronary disease", "cardiovascular system", "osteoarthritis" and "obesity". Study results were synthesized in table or graphic format only.

Recommendations were graded as:

A Good evidence to support the recommendation that the condition be specifically considered in a PHE.

B Fair evidence to support the recommendation that the condition be specifically considered in a PHE.

C Poor evidence regarding inclusion or exclusion of the condition in a PHE, but recommendations may be made on other grounds.

D Fair evidence to support the recommendation that the condition be specifically excluded from consideration in a PHE.

E Good evidence to support the recommendation that the condition be specifically excluded from consideration in a PHE.

Quality of evidence was rated according to 5 levels:

I Evidence from at least 1 properly randomized controlled trial (RCT).

II-1 Evidence from well-designed controlled trials without randomization.

II-2 Evidence from well-designed cohort or case-control analytic studies, preferably from more than 1 centre or research group.

II-3 Evidence from comparisons between times or places with or without the intervention. Dramatic results in uncontrolled experiments could also be included here.

III Opinions of respected authorities, based on clinical experience, descriptive studies or reports of expert committees.

Values

The 13-member Task Force of experts in family medicine, geriatric medicine, pediatrics, psychiatry and epidemiology used an evidence-based method for evaluating the effectiveness of preventive health care interventions. Recommendations were not based on cost-effectiveness of options. Patient preferences were not discussed.

Background papers providing critical appraisal of the evidence and tentative recommendations prepared by the chapter author were pre-circulated to the members. Evidence for this topic was presented and deliberated upon in 1- to 2-day meetings, 2 to 3 times per year from January 1993 to June 1993. Consensus was reached on final recommendations.

Benefits, Harms, and Costs

Cohort studies report a consistent, strong, graded association between physical activity and incidence of CHD in men. Insufficient evidence exists for women. They also suggest that persons who are sedentary have a 35% to 52% increased risk for developing hypertension, independent of other risk factors.

Prospective population studies and experimental studies on the secondary prevention of obesity found that increased relative risk for significant weight gain was associated with low physical activity level. Exercise alone had a significant effect on weight, but a combination of diet and exercise was most effective for preventing obesity and maintaining ideal body weight.

Cohort data indicate an inverse relationship between level of activity and risk for developing NIDDM, with a more pronounced effect in men who are overweight. The age-adjusted risk for NIDDM was reduced by 6% for each 500-kcal increment in energy expenditure per week.

A non-randomized trial found that weight-bearing exercise in postmenopausal women retarded bone loss. The effect on bone density was modest (20%) when compared with the genetic contribution.

Potential adverse effects of exercise include injury, osteoarthritis, myocardial infarction and sudden death. Few data exist on the incidence of injury during non-competitive sports. Injuries are often due to excessive levels of activity or improper techniques, and, therefore, are preventable. Data from case-control studies do not support that long-term activity leads to osteoarthritis. 2 large cohort studies have shown that heavy physical activity can increase risk of acute MI by 2.1% (95% CI 1.6 to 3.1) to 5.9% (95% CI 4.6 to 7.7). Both studies reported a protective effect of regular physical activity. Another study found an increased risk for sudden death among sedentary individuals who engaged in vigorous activity.

Studies on the effectiveness of physician counselling provide little information on long-term compliance and have limited generalizability.

Recommendations

Recommendation grade [A, B, C, D, E] and level of evidence [I, II-1, II-2, II-3, III] are indicated after each recommendation. Citations in support of individual recommendations are identified in the guideline text.

Fair evidence exists to recommend that individuals engage in regular moderate-level physical activity to accumulate ł 30 minutes for most days of the week [B, II-2].
Insufficient evidence exists to recommend for or against regular weight-bearing exercise by women before and after menopause [C, II-1].
Insufficient evidence exists to recommend for or against physical activity counselling about activity level, health benefits of regular moderate activity and dangers of vigorous activity for unfit individuals [C, III].

Validation

This report was externally peer-reviewed. Recommendations and background papers were sent for external peer review. Health Canada, Canada Fitness and most provinces have developed intervention programs to encourage increased activity. The 1989 U.S. Preventive Services Task Force recommended physician counselling for regular physical activity. The American College of Sports Medicine has issued guidelines about cardiorespiratory fitness, body composition, muscular strength and endurance.

Selected References

Source Document

Beaulieu MD. Physical activity counselling. In: Canadian Task Force on the Periodic Health Examination. Canadian Guide to Clinical Preventive Health Care. Ottawa: Health Canada, 1994; 560-69.

Link to Full Text of this review

Link to Summary Table of Recommendations of this review

Link to Selected References list of this review

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A	Good evidence to support the recommendation that the condition be specifically considered in a PHE.
B	Fair evidence to support the recommendation that the condition be specifically considered in a PHE.
C	Poor evidence regarding inclusion or exclusion of the condition in a PHE, but recommendations may be made on other grounds.
D	Fair evidence to support the recommendation that the condition be specifically excluded from consideration in a PHE.
E	Good evidence to support the recommendation that the condition be specifically excluded from consideration in a PHE.

I	Evidence from at least 1 properly randomized controlled trial (RCT).
II-1	Evidence from well-designed controlled trials without randomization.
II-2	Evidence from well-designed cohort or case-control analytic studies, preferably from more than 1 centre or research group.
II-3	Evidence from comparisons between times or places with or without the intervention. Dramatic results in uncontrolled experiments could also be included here.
III	Opinions of respected authorities, based on clinical experience, descriptive studies or reports of expert committees.