Physical Activity Guidelines for Americans - 2008 Implications for Cardiovascular Disease Prevention & Management

1. Physical Activity Guidelines for Americans - 2008 Implications for Cardiovascular Disease Prevention & Management William L. Haskell, PhD Stanford Prevention Research Center & Division of Cardiovascular Medicine School of Medicine, Stanford University Presentation Outline • Evolution of Physical Activity & Public Health Guidelines • Physical activity guidelines for general health improvement vs. guidelines for optimal body weight management • Physical Activity Guidelines for Americans - 2008 • 2008 Guidelines - CVD prevention & management • An approach based on recent research & integration

2. The Exercise Training Paradigm Early guidelines & recommendations (AHA 1972, 1975, ACSM 1978, 1990) were based primarily on endurance exercise to enhance performance - especially cardiorespiratory fitness. Vigorous exercise ≥ 20 min ≥ 3 x week TRAINING PERFORMANCE RATIONALE: Increases in aerobic capacity are most rapidly achieved by increasing the intensity of endurance exercise and higher aerobic capacity is associated with reduced risk of CVD

3. Background - Physical Activity and CVD Prevention • In 1992 the American Heart Association made physical inactivity their 4th. major CHD risk factor (added to cigarette smoking, high blood pressure and high cholesterol). • In 1996 a NIH Consensus Development Panel concluded that physical inactivity was a major, independent risk factor for CHD. • In 1996 in Physical Activity and Health: A Report of the Surgeon General it was concluded that physical inactivity was a major, independent risk factor for CHD.

4. The Physical Activity - Health Paradigm Public health oriented guidelines since 1995 (CDC/ACSM, Surgeon General Report, NIH consensus panel). include the accumulation of ≥ 30 minutes of moderate intensity activity on most days of the week & vigorous recommendation still applies. ACTIVITY HEALTH RATIONALE: Data from observational and experimental studies demonstrate health-related outcomes from moderate intensity activity accumulated throughout the day.

5. Rationale to Update 1995 and 1996 Recommendations • Since 1995 substantial amount of new research published on health benefits of physical activity - some of it stimulated by 1995 recommendations. • There were a number of questions raised by how the the 1995 recommendations were stated. • Recommendations from other organizations were creating confusion, especially about the amount of exercise recommended - especially recommendations dealing primarily with prevention of unhealthy weight gain, weight loss and weight regain.

6. Dietary Guidelines for Americans - 2005 USDHHS & USDA, January 2005 PHYSICAL ACTIVITY • To reduce the risk of chronic disease in adulthood engage in at least 30 minutes of moderate-intensity physical activity, above usual activity on most days of the week. • For most people, greater health benefits can be obtained by engaging in physical activity of more vigorous intensity or longer duration. • To help manage body weight and prevent gradual, unhealthy body weight gain in adulthood: Engage in approximately 60 minutes of moderate- to vigorous-intensity activity on most days while not exceeding caloric intake requirements.

7. Dietary Guidelines for Americans - 2005 USDHHS & USDA, January 2005 PHYSICAL ACTIVITY(continued) • To sustain weight loss in adulthood: Participate in at least 60 to 90 minutes of daily moderate-intensity physical activity while not exceeding caloric intake requirements. Some people may need to consult with a healthcare provider before participating in this level of activity. • Achieve physical fitness by including CV conditioning, stretching exercises for flexibility, & resistance exercises or calisthenics for muscle strength & endurance.

8. CDC and DHHS - an Issue Regarding Federal Physical Guidelines • In 2002 development of update to 1995 PA & PH recommendations started by CDC and ACSM. • In 2006 when advanced draft of the two manuscripts were reviewed by CDC, they were required to obtain DHHS approval. • DHHS & CDC decided not to issue new recommendations because Federal Physical and Health Recommendations existed - as part of the Dietary Guidelines for Americans - 2005. • ACSM and AHA proceeded with publications of the updated recommendations in 2007.

9. Physical Activity & Public Health - 2007 Recommendations for Generally Healthy Adults • To promote and maintain good health and help prevent chronic disease, adults should perform moderate-intensity (3.0 - 6.0 METS) aerobic (endurance) physical activity for a minimum of 30 minutes on five days each week. • Or, this recommendation can be met by performing vigorous-intensity activity for at least 20 minutes on 3 days each week. • Combinations of moderate- and vigorous-intensity endurance exercise can be performed to meet this recommendation. • This activity is in addition to the required activities of daily living that are of light intensity or short duration.

10. Physical Activity Recommendations (cont.) • Given the general dose-response relation between physical activity and chronic disease prevention, greater benefits will result from exceeding these recommendations. • The ≥ 30-minute target for moderate-intensity exercise can be accumulated throughout the day in bouts of ≥ 10 minutes. • All adults should include a regimen of resistance (strength developing) exercise 2 x week consisting of one or two sets of 8-10 exercises with 10-12 repetitions at near maximal effort involving all major muscle groups of the body.

11. Physical Activity Recommendations for Healthy Adults ≥ 65 Years of Age • Aerobic Activity: ≥ 30 minutes of moderate intensity on 5 days/week or ≥ 20 minutes of vigorous intensity on 3 days/week. • Muscle-strengthing activity: 8-10 exercises @ 10-15 reps performed on 2 non-consecutive days • Flexibility exercises: 10 minutes on ≥ 2 days/week • Balance promoting activity: should perform activities that help maintain balance and prevent falls. • Other: more activity = greater benefit, can combined moderate with vigorous to meet goals, safety needs to be considered

12. CDC and DHHS - an Issue Regarding Federal Physical Guidelines • Lobbying inside and outside DHHS resulted in the DHHS Secretary authorizing development of Physical Activity Guidelines for Americans - 2008 • IOM workshop held October 2006 to establish that there was adequate evidence to proceed. • Physical Activity Guidelines Advisory Committee appointed in February 2007 to prepare an extensive report on the evidence linking physical activity and health between 1995-2007. DHHS staff to prepare guidelines and policy statements. • CDC authorized to conduct extensive literature search on key health outcomes - data published since 1995.

13. Outcome Areas • All-cause mortality • Cardiorespiratory health • Musculoskeletal health • Metabolic health • Energy balance & maintenance of healthy weight • Cancer • Functional health - especially in older adults • Mental health • Youth • Adverse events & safety • Understudied populations

14. Cardiorespiratory Health Summary - Review of Observational Studies • Observational studies reporting on PA in primary prevention published between January 1996 and August 2007 • CVD: 21 observational studies of PA Men = 18 studies, >75,000 participants Women = 17 studies, >300,000 participants • CHD: 23 observational studies of PA Men = 14 studies, > 200,000 participants Women = 16 studies, >275,000 participants • Stroke: 21 observational studies of PA Men = 15 studies, >120,000 participants Women = 17 studies, >175,000 participants

15. PAGAC Report - Cardiorespiratory Health What observational studies published since 1996 provide - • Improved methodology - better assessment of PA, outcomes and possible confounding factors • Larger study populations and more events • More data on women and older men • More diverse ethnic/race populations • Many studies provide clinical outcome data on at least least three categories (levels) of activity thus provide some information on dose-response.

16. PAGAC - Consensus on Amount of Aerobic Activity “For many studies, the amount of moderate and vigorous intensity activity associated with significantly lower rates of disease or improvements in biomarkers and fitness is in the range of500 to 1,000 MET-minutes per week.” Note: the lack of precision of the science across populations and outcomes dictates wide range “An adult can achieve a target of 500 MET-minutes per week by walking at about 3.0 miles per hour for approximately150 minutes per week (7.5 miles), walking faster at 4.0 miles per hour for 100 minutes (6.6 miles) or jogging or running at 6 miles per hour for about 50 minutes per week (5.0 miles). “

17. Physical Activity and Cardiorespiratory Health • What is the relation between physical activity and cardiovascular disease morbidity and mortality? • Conclusions • Data from prospective cohort studies and case-control studies (1995-2007) support a strong and consistent inverse association between level of physical activity and CHD or CVD morbidity and mortality. • Men and women who report moderate levels of physical activity experience a 20% - 25% lower risk than their least active counterparts, while those reporting higher levels of activity experience a 30% - 35% lower risk than the least active.Based on 68 study groups in prospective cohort studies and case-control studies with approximately 872,000 subjects.

18. Physical Activity and Cardiorespiratory Health What are the dose response relations between physical activity and cardiovascular morbidity and mortality? • Conclusion • Much of the data since 1995 has been on LTPA with some data on TPA, occupational work and commuting. Most dose response data are based on amount of activity performed per day or week with limited data on activity intensity. Use of a variety of measures makes merging of data across studies difficult. Of 33 studies reporting analysis for significance of dose response, 21 (64%) were significant (p for trend <0.05). • The data are quite consistent in showing a significant benefit with ≥2.0 hrs/week or 5-10 MET-hrs/week of moderate intensity activity. Lower amounts of activity frequently show some benefit, especially when the comparison group is very inactive. Greater benefit is associated with higher levels of activity. Substantial amounts of inactivity (lying, sitting, standing quietly) are associated with a major increase in risk.

19. Physical Activity and Cardiorespiratory Health • What is the relation between physical activity and cerebrovascular disease morbidity and mortality? Conclusions • Based on the results of 24 study groups (approximately 347,000 subjects) in prospective cohort and case control studies there is a reasonably strong and consistent inverse association for both men and women between amount of habitual physical activity performed and morbidity and mortality resulting from strokes (most data on ischemic stroke). • As compared to the least active, persons reporting moderate or high levels of physical activity have approximately a 25% lower risk of all and ischemic stroke. Results shown greater between study variability than data for CHD and CVD.

20. Physical Activity and Cardiorespiratory Health What are the dose response relations between physical activity and cerebrovascular disease (strokes)? • Conclusion • Of 24 sex specific reports on physical activity and stroke, 12 reported an analysis of dose-response with 9 (75%) reporting a significant p for trend across 3 or more levels of activity. However, the median RR for moderate/low and high/low levels of activity are quite similar. • Lower rates of stroke are quite consistently reported when ≥2.0 hours /week or 5.0 - 10.0 MET-hrs/week of moderate intensity activity is performed. Lower levels of activity are inconsistently inversely related to stroke occurrence.

21. Report of the Physical Activity Guidelines Advisory Committee - 2008 Energy balance & maintenance of healthy weight 1. What is the amount of physical activity that is necessary for weight stability over the long-term (≤ 3% change in weight)? The optimal amount of physical activity needed for weight maintenance over the long-term is unclear. RCTs lasting up to 12 months indicate activity volume of 13 to 26 MET-hrs/week is associated with approximately a 1% - 3% weight loss (≥ 150 min/week of walking at 4 mph or jogging at 6 mph for ≥75 min/week).

22. Report of the Physical Activity Guidelines Advisory Committee - 2008 Energy balance & maintenance of healthy weight 2. What is the evidence for amount of physical activity that is necessary for weight loss in adults (≥ 5% change in weight)? Clear and consistent data show that a large volume of physical activity is needed for weight loss in the absence of concurrent dietary changes. The physical activity equivalent of 25 kilocalories of body weight/week: ≥1,560 MET-minutes/week is needed for weight loss (walking at 4 mph ≥45 min/day, 3 mph ≥70 min/day or jogging at 6 mph ≥ 22 min/day.

23. Report of the Physical Activity Guidelines Advisory Committee - 2008 Energy balance & maintenance of healthy weight 3. Is there evidence that physical activity provides for weight maintenance in adults who have previously lost substantial body weight? Evidence for the effectiveness of physical activity alone in preventing weight regain is limited. Available data indicate that to prevent substantial weight regain over ≥ 6 months many adults need to exercise in the range of 60 minutes of walking or 30 minutes of jogging daily. Data support the concept that “more is better”.

24. Report of the Physical Activity Guidelines Advisory Committee - 2008 Energy balance & maintenance of healthy weight 4. For persons who are overweight or obese is there evidence that physical activity provides health benefits irrespective of assisting with energy balance? Yes, strong evidence shows that physically active adults who are overweight or obese experience a variety of health benefits that are generally similar to those observed in people of optimal body weight (BMI 18.5-25.0). Because of the health benefits of physical activity that are independent of body weight classification, adults of all sizes and shapes gain health and fitness benefits by being habitually physically active.

25. Physical Activity Guidelines for Americans - 2008Adults and Older Adults • All adults should avoid inactivity. Some activity is better than none, and adults who participate in any amount of physical activity gain some health benefits. • For substantial health benefits, adults should do at least 150 minutes of moderate-intensity, or 75 minutes of vigorous-intensity activity each week (Public Health Target) <www.health.gov/paguidelines>

26. Physical Activity Guidelines for Americans - 2008Adults and Older Adults • Mix moderate and vigorous intensity activity to meet the aerobic activity goal (500 - 1000 MET-minutes/week). • Aerobic activity can be accumulated in bouts of 10 minute or longer (e.g., 3 x 10 minutes/day) • Resistance exercise should be performed 2 x week: 1-2 sets (10-12 repetitions) of 8-10 exercises of major muscle groups. • Start low, build slowly - the major goal is long-term maintenance. <www.health.gov/paguidelines>

27. Recommendations Based on Recent PAGAC Review/Integration & Clinical Experience 1. Get the least active moving • Persons at the greatest risk for various chronic diseases and disability consistently are those who are the least active. • This risk appears independent of age, gender, race/ethnicity, body size or shape or disability. • Many of these people report no moderate- or vigorous intensity activity on most days

28. Relative Risk of CVD in Women - Walking Amount/Week Manson - 1999 Manson - 2002 Lee - 2001 P for trend Quintile MET/hrs/wk MET-hrs/wk Min/week <0.5 0.6-2.0 2.1-3.8 3.9-9.9 ≥10.0 <0.001 0 0.1-2.5 2.6-5.0 5.1-10.0 >10.0 <0.001 0 1-59 60-90 >120 <0.001

29. Recommendations Based on Recent PAGAC Review/Integration & Clinical Experience 2. Work to build activity into the daily lives of the inactive • For least active, even activity less that the “Public Health Target” provides some health benefits • In this population “moving about” appears to be better than sitting for some outcomes (exactly how much we are not sure) • Initial goal is to change “inactive mind-set” and perform mini-bouts of activity throughout the day

30. Association of 2-hour plasma glucose with quartiles of percentage of waking hours spent in various activities Sedentary Time 173 men and women with type 2 Diabetes (53 ±11.9 years) Physical activity measured during waking hours for 7 days using Actigraph All Sedentary <100 counts/min 8.4 (8.2-8.6) Light = 100-1951 counts/min 5.8 (5.7-6.0) Mod + Vig ≥ 1952 counts/min 0.6 (0.5-0.6) Light Intensity Mod. To Vig. Intensity Healy, et al. Diabetes Care. 30:1384, 2007 Australian Diabetes, Obesity & Lifestyle Study

31. Recommendations Based on Recent PAGAC Review/Integration & Clinical Experience 3. The initial long-term goal for all individuals should be the “Public Health Target” • “For many studies, the amount of moderate and vigorous intensity activity associated with significantly lower rates of disease or improvements in biomarkers and fitness is in the range of500 to 1,000 MET-minutes per week.” • An adult can achieve a target of 500 MET-min/week by walking at about 3.0 mph for 150 min/week (7.5 miles), walking faster at 4.0 mph for 100 minutes (6.6 miles) or jogging or running at 6 mph for about 50 min/week (5.0 miles).

32. Meeting Public Health Physical Activity Recommendations and Mortality NIH-AARP Diet & Health Study Relative Risk All-Cause CVD Cancer N = 252,925 men and women Age 50-71; follow-up = 5.5 years Multivariate-adjusted relative risk Leitzmann, et al. Archives Int. Med. 2007. 167:2453-2460.

33. Recommendations Based on Recent PAGAC Review/Integration & Clinical Experience 4. If reach “Public Health Target” and not at desired body weight then implement additional weight management strategies • Need to consider revision of calorie restriction regimen and/or additional physical activity • If major activity has been endurance/aerobic, should consider the addition of some resistance exercise