Comparison of cardioprotective benefits of vigorous versus moderate intensity aerobic exercise

Physical activity intensity and risk of overweight and adiposity in children

BACKGROUND

Physical activity recommendations for children focus on duration of activity and underemphasize intensity.

OBJECTIVE

To evaluate the relationship between physical activity (intensity and duration) and the odds of being overweight, >20% body fat and >25% body fat.

METHODS AND PROCEDURES

Body fat, BMI and physical activity (accelerometry) were measured in children (n = 251) aged 8-10 years. Physical activity was quantified as time in moderate physical activity (MPA) and vigorous physical activity (VPA).

RESULTS

Prevalence of overweight and obesity were 18 and 11.6%, respectively. Regression indicated that VPA, not MPA, is associated with body fat (r = 0.35, P < 0.001) and BMI (r = 0.26, P < 0.001). Odds ratio demonstrated a significant impact of MPA and VPA on body composition. Children performing < or =5 min/day of VPA are 4.0 times more likely to have > or =20% body fat (P < 0.001), 2.9 times more likely to have > or =25% body fat (P < 0.05) and 5.2 times more likely to be classified as overweight (P < 0.01) compared to children performing > or =15 min/day. Those performing < or =15 min/day of MPA vs. >45 min/day MPA are at 4.2 increased odds of having > or =20% body fat (P < 0.001), and 3.0 increased odds of having > or =25% (P < 0.01).

DISCUSSION

Lower durations of both MPA and VPA are associated with increased odds of overweight and adiposity. Forty-five minutes of MPA and fifteen minutes of VPA were associated with reduced body fat and BMI. We recommend that these amounts are used to develop minimum physical activity intensity guidelines for the prevention and treatment of obesity.

British adults' views on the health benefits of moderate and vigorous activity

OBJECTIVE

It has been suggested that the promotion of moderate-intensity physical activity has created a widespread belief that moderate activity offers greater health benefits than vigorous activity. The present study was designed to test this hypothesis in Britain, where moderate activity has solely been recommended since 1995.

METHODS

Nationally representative survey of 1191 Britons aged 16-65 surveyed from March 3rd to May 12th 2006.

RESULTS

In support of the hypothesis, 56% of men and 71% of women aged 25-65 indicated that moderate activity offered greater health benefits than vigorous activity and indicated that moderate activity was recommended.

CONCLUSIONS

Policymakers have an obligation to equip the public to make fully informed decisions about physical activity and health. British physical activity guidelines should be amended because most men and women erroneously believe that moderate activity offers greater health benefits than vigorous activity.

Vigorous exercise and diabetic, hypertensive, and hypercholesterolemia medication use

PURPOSE

The prevalences of diabetes, hypertension, and high cholesterol all decrease with increased levels of physical activity and cardiorespiratory fitness. Whether these reductions extend beyond contemporary guideline activity levels and whether fitness affects medication use independent of activity, remains unclear.

METHODS

Cross-sectional analyses of 62,291 male and 45,041 female runners, of whom 496 used antidiabetic, 3738 used antihypertension, and 2360 used low-density lipoprotein cholesterol (LDL-C)-lowering medications. Cardiorespiratory fitness was reported as speed (m x s(-1)) during a 10-km foot race.

RESULTS

Medication use was significantly inversely associated with activity and fitness (P < 0.001, except LDL-C-lowering versus women's fitness). Compared with < or = 16 km x wk(-1) (guideline levels), the odds in men and women who ran > 64 km x wk(-1) were, respectively, 69% and 55% lower for antidiabetic, 48% and 52% lower for antihypertension, and 64% and 51% lower for LDL-C-lowering medication use. Compared with the least-fit men (< 3.25 m x s(-1)) and women (< 2.8 m x s(-1)), the odds for those who were most fit (men > 4.75 m x s(-1); women > 4.0 m x s(-1)) were 58% and 65% lower for antidiabetic, and 76% and 55% lower for antihypertensive medication use. Odds for LDL-C-lowering medication use were 87% lower in the fittest versus the least-fit men. Adjustment for activity only moderately diminished the inverse relationships of fitness with medication use.

CONCLUSION

Among individuals who exceed current guideline levels, antidiabetic, antihypertension, and LDL-C-lowering medications are inversely related to vigorous physical activity and cardiorespiratory fitness. Lower odds of medication use with higher fitness occur independently of physical activity.

Physical Activity and Public Health

SUMMARY

In 1995 the American College of Sports Medicine and the Centers for Disease Control and Prevention published national guidelines on Physical Activity and Public Health. The Committee on Exercise and Cardiac Rehabilitation of the American Heart Association endorsed and supported these recommendations. The purpose of the present report is to update and clarify the 1995 recommendations on the types and amounts of physical activity needed by healthy adults to improve and maintain health. Development of this document was by an expert panel of scientists, including physicians, epidemiologists, exercise scientists, and public health specialists. This panel reviewed advances in pertinent physiologic, epidemiologic, and clinical scientific data, including primary research articles and reviews published since the original recommendation was issued in 1995. Issues considered by the panel included new scientific evidence relating physical activity to health, physical activity recommendations by various organizations in the interim, and communications issues. Key points related to updating the physical activity recommendation were outlined and writing groups were formed. A draft manuscript was prepared and circulated for review to the expert panel as well as to outside experts. Comments were integrated into the final recommendation.

PRIMARY RECOMMENDATION

To promote and maintain health, all healthy adults aged 18 to 65 yr need moderate-intensity aerobic (endurance) physical activity for a minimum of 30 min on five days each week or vigorous-intensity aerobic physical activity for a minimum of 20 min on three days each week. [I (A)] Combinations of moderate- and vigorous-intensity activity can be performed to meet this recommendation. [IIa (B)] For example, a person can meet the recommendation by walking briskly for 30 min twice during the week and then jogging for 20 min on two other days. Moderate-intensity aerobic activity, which is generally equivalent to a brisk walk and noticeably accelerates the heart rate, can be accumulated toward the 30-min minimum by performing bouts each lasting 10 or more minutes. [I (B)] Vigorous-intensity activity is exemplified by jogging, and causes rapid breathing and a substantial increase in heart rate. In addition, every adult should perform activities that maintain or increase muscular strength and endurance a minimum of two days each week. [IIa (A)] Because of the dose-response relation between physical activity and health, persons who wish to further improve their personal fitness, reduce their risk for chronic diseases and disabilities or prevent unhealthy weight gain may benefit by exceeding the minimum recommended amounts of physical activity. [I (A)]

Physical Activity and Public Health

SUMMARY

In 1995 the American College of Sports Medicine and the Centers for Disease Control and Prevention published national guidelines on Physical Activity and Public Health. The Committee on Exercise and Cardiac Rehabilitation of the American Heart Association endorsed and supported these recommendations. The purpose of the present report is to update and clarify the 1995 recommendations on the types and amounts of physical activity needed by healthy adults to improve and maintain health. Development of this document was by an expert panel of scientists, including physicians, epidemiologists, exercise scientists, and public health specialists. This panel reviewed advances in pertinent physiologic, epidemiologic, and clinical scientific data, including primary research articles and reviews published since the original recommendation was issued in 1995. Issues considered by the panel included new scientific evidence relating physical activity to health, physical activity recommendations by various organizations in the interim, and communications issues. Key points related to updating the physical activity recommendation were outlined and writing groups were formed. A draft manuscript was prepared and circulated for review to the expert panel as well as to outside experts. Comments were integrated into the final recommendation.

PRIMARY RECOMMENDATION

To promote and maintain health, all healthy adults aged 18 to 65 yr need moderate-intensity aerobic (endurance) physical activity for a minimum of 30 min on five days each week or vigorous-intensity aerobic physical activity for a minimum of 20 min on three days each week. [I (A)] Combinations of moderate- and vigorous-intensity activity can be performed to meet this recommendation. [IIa (B)] For example, a person can meet the recommendation by walking briskly for 30 min twice during the week and then jogging for 20 min on two other days. Moderate-intensity aerobic activity, which is generally equivalent to a brisk walk and noticeably accelerates the heart rate, can be accumulated toward the 30-min minimum by performing bouts each lasting 10 or more minutes. [I (B)] Vigorous-intensity activity is exemplified by jogging, and causes rapid breathing and a substantial increase in heart rate. In addition, every adult should perform activities that maintain or increase muscular strength and endurance a minimum of two days each week. [IIa (A)] Because of the dose-response relation between physical activity and health, persons who wish to further improve their personal fitness, reduce their risk for chronic diseases and disabilities or prevent unhealthy weight gain may benefit by exceeding the minimum recommended amounts of physical activity. [I (A)].