Edward Melanson, Ph.D., Associate Professor, Division of Endocrinology, Metabolism, and Diabetes University of Colorado Denver 45 y/o man Medications: none Social Hx: moderate alcohol intake (1-2 cans of beer each night), poor diet, sedentary lifestyle Family Hx: father recently diagnosed with NIDDM Exam: HT=70, Wt=210 lbs, BMI=30.1 kg/m 2, WC-44 Fasting Labs: Glucose=105 mg/dl, Total C=210 mg/dl, HDL-C=38 mg/dl, TG=175 mg/dl LDL=137 mg/dl Goal: Wants to start exercising to lose some weight; his goal is 20 lbs. He is also motivated by his fatherʼs diagnosis, he wants to change his lifestyle to reduce his risk of becoming diabetic. 1. How much exercise would you recommend to reduce his risk of becoming diabetic? 2. How much exercise would you recommend if his goal is to lose 20 lbs in the next 4 months (is this a realistic goal)? 3. What type of exercise would you recommend (and why)?
Physical activity recommendations Exercise for weight loss Exercise for maintenance of weight loss Physical inactivity and metabolic health Case discussion Prior to 1995, recommendations were based on improving CV fitness ACSM CDC Statement (JAMA. 1995) 150-200 mins per week (~1000 kcal/wk) of moderate-intensity, accumulated, physical activity to reduce risk of chronic disease Updated recommendation (Circulation, 2007) To promote and maintain health, minimum of 30 min of moderateintensity aerobic (endurance) physical activity 5 days/week or a minimum of 20 min of vigorous intensity on three days each week. Moderate-intensity activity brisk walk and noticeably accelerates HR Vigorous-intensity activity (e.g. jogging) 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.
Diet and exercise were designed to induce a deficit of 700 kcal per day Which group lost more weight?
ACSM Position Stand. (Med Sci Sports Exerc. 2001) Review of multiple intervention studies 200-300 min per week of moderate-intensity physical activity per week may facilitate the long-term maintenance of weight loss IOM consensus statement (AJCN 2004) Based on analysis of a small number of cross-sectional studies; determined physical activity levels required to maintain normal body weight (healthy BMI) > 300 mins per week of moderate-intensity physical activity to promote weight loss and decrease risk of weight gain Reexamined the evidence published after 1999 150-250 min/wk Moderate intensity PA effective to prevent weight gain, but will only produce modest weight loss. >250 min/wk to induce clinically significant weight loss and maintain weight loss. Resistance training does not enhance weight loss but may increase fat-free mass and increase loss of fat mass and is associated with reductions in health risk. Existing evidence indicates that endurance exercise or resistance training without weight loss improves health risk.
Cunningham, AJCN, 54(6), 1991 22 kcal. kg FFM -1. Day -1 Lemmer et al., MSSE, 33(4), 2001 Young women = 17 kcal. kg FFM -1. Day -1 Older women = 63 kcal. kg FFM -1. Day -1 Young men = 101 kcal. kg FFM -1. Day -1 Older men = 131 kcal. kg FFM -1. Day -1 Average weight loss is 66 lbs (5.5 years) 45% of lost weight on their own, 55% lost weight with the help of some type of program. 98% of report that they modified their food intake; 94% increased their physical activity, with the most frequently reported form of activity being walking. Most report continuing to maintain a low calorie, low fat diet and doing high levels of activity. Other facts 78% eat breakfast every day. 75% weigh them self at least once a week. 62% watch less than 10 hours of TV per week. 90% exercise, on average, about 1 hour per day.
Intensity (%VO2max) Kcal/wk 70-85% 2000 50-65% 1000 50-65% 2000 70-85% 1000 Percentage of weight loss based on randomized group assignment (n = 191) Jakicic, J. M. et al. Arch Intern Med 2008;168:1550-1559. Copyright restrictions may apply. Percentage weight loss by physical activity categories (minutes per week) (n = 170) Jakicic, J. M. et al. Arch Intern Med 2008;168:1550-1559. Copyright restrictions may apply.
It requires an energy deficit of ~3500 kcal to produce 1 pound of weight loss To lose weight at a rate of a pound a week, this is equivalent to a deficit of 500 kcal per day How much exercise has to be done to produce a deficit of 500 kcal per day? At 60% of maximal aerobic capacity 42 YO male, 65, 132 lbs, BMI = 22.0 kg/m 2 _ VO 2 max = 4.06 L/min _ 2.4 L/min x 5 kcal/l O 2 = 12.2 kcal/min (41 mins) 42 YO male, 73, 235 lbs, BMI = 31.0 kg/m 2 _ VO 2 max = 3.31 L/min, 10 kcal/min, 60 mins 52 YO female, 66, 170 lbs, BMI = 27.5 kg/m 2 _ VO 2 max = 2.00 L/min, 6 kcal/min, 83 mins
Copyright restrictions may apply. _ Insulin resistance (OGTT) _ Insulin resistance (OGTT) _ Visceral adiposity _ Fat free mass Olsen, R. H. et al. JAMA 2008;299:1261-a-1263-a. Physical inactivity and CVD Risk Men who reported > 10 h/wk of riding in a car or > 23 h/wk of total sedentary behavior (riding in a car, watching TV) had higher rates of CVD mortality High levels of physical activity were associated with lower CVD mortality even in the presence of high levels of sedentary time
Copyright restrictions may apply. Bravata, D. M. et al. JAMA 2007;298:2296-2304. An important predictor of increased PA was having a step goal (e.g. 10,000 steps) Pedometer users achieved a significant reduction in BMI (0.38 kg/m2) and systolic blood pressure (3.8 mm Hg) Losing weight and maintaining weight loss is difficult 150-250 mins of moderate intensity exercise will reduce risk of future wt gain, but does not guarantee wt loss or even wt maintenance _ >250 min/wk is more likely to produce weight loss _ Wt loss via exercise alone is likely to be modest (5-10%) Improving CV fitness may increase likelihood that exercise will promote weight loss 45 y/o man Medications: none Social Hx: moderate alcohol intake (1-2 cans of beer each night), poor diet, sedentary lifestyle Family Hx: father recently diagnosed with NIDDM Exam: HT=70, Wt=210 lbs, BMI=30.1 kg/m 2, WC-44 Fasting Labs: Glucose=105 mg/dl, Total C=210 mg/dl, HDL-C=38 mg/dl, TG=175 mg/dl LDL=137 mg/dl Goal: Wants to start exercising to lose some weight; his goal is 20 lbs. He is also motivated by his fatherʼs diagnosis, he wants to change his lifestyle to reduce his risk of becoming diabetic.
How much exercise would you recommend to reduce his risk of becoming diabetic? a) 30 minutes per day of moderate intensity exercise, 3 b) 30 minutes per day of moderate intensity exercise, 5 c) 30 minutes per day of vigorous intensity exercise, 3 d) 30 minutes per day of vigorous intensity exercise, 5 How much exercise would you recommend if his goal is to lose 20 lbs in the next 4 months (is this a realistic goal)? a) 30 minutes per day of moderate intensity exercise, 3 b) 30 minutes per day of moderate intensity exercise, 5 c) 60 minutes per day of moderate intensity exercise, 5 d) 30 minutes per day of vigorous intensity exercise, 3 What type of exercise would you recommend (and why)? a) Low intensity aerobic exercise (e.g. ~40-60% of maximal aerobic capacity) b) High intensity aerobic exercise (e.g. >75% of maximal aerobic capacity) c) Resistance exercise training d) A combination of resistance and aerobic exercise training