Physical activity in Healthy Adults and in Weight Management Alexandra M. Rivera Vega Assistant Professor Physical Medicine and Rehabilitation UAMS

Definitions  Physical activity(PA)  Any bodily movement produced by skeletal muscles that results in energy expenditure above resting(basal) levels  Encompasses exercise, sports, and physical activities done as part of daily living, occupation, leisure and active transportation  Exercise  Physical activity that is planned, structured, repetitive and has a final or intermediate objective the improvement or maintenance of physical fitness

Health benefits of Physical Activity and Exercise in adults  Decrease blood pressure  Decrease risk of developing CHD, Stroke, DM II, Cancer (colon,breast)  Improve CHD biomarkers (lipoprotein, C- reactive protein)  Preserves bone mass, reduces risk of falling  Prevents/improves depression and anxiety

American College of Sports Medicine recommendations Regular Exercise Cardiorespirator y Resistance Neuromuscular Exercises Flexibility

American College of Sports Medicine recommendations  Cardiorespiratory  Moderate -intensity ≥ 30min/d on ≥ 5 d/wk (total >150min/wk)  Vigorous intensity ≥ 20min on ≥ 3d/wk (≥ 75 min/wk)  Combination of moderate and vigorous intensity exercise for a total energy expenditure ≥ MET/min/wk  Resistance exercises  Major muscle groups  Neuromotor exercises  Balance, agility, coordination  Flexibility exercises  Major muscle-tendons, 60s/exercise, >= 2d/wk

American College of Sports Medicine recommendations  Reducing total time engaged in sedentary pursuits and also by interspersing frequent, short bouts of standing and physical activity between periods of sedentary activity, even in physically active adults

Physical activity and Weight Management PA Prevent Weight Gain >3% Moderate/Vigorous PA min/wk kcal/wk miles/wk PA Promote Weight Lost PA <150 min/wk= minimal weight lost PA>150 min/wk= kg PA min/wk = kg PA Prevent Weight Regain after Weight Lost More is Better Need better study designs in order to address each level of PA after weight loss

Overview of Lifestyle Physical Activity  Lifestyle intervention approaches (to increasing PA) vs Lifestyle forms of PA  Lifestyle approaches to increasing PA: interventions that incorporate behavioral theories and constructs to assist and facilitate increasing PA within one lifestyle  Goal setting, self monitoring, relapse prevention strategies  Lifestyle forms of PA : more challenging, is a non- structured form of PA not intended to constitute a structured period of exercise  Walking for commuting, using stairs instead of elevator

Physical Activity is useful for weight management  Higher levels of Lifestyle PA prevent initial weight gain Sitting at work, home or leisure time Low levels of energy expenditure Obesity Epidemic

Physical activity combined with energy restriction will increase weight loss  Physical activity and Diet restriction provide comparable weight loss if they provide similar levels of energy deficits  Physical activity will increase weight loss in combination with Diet restriction if the diet restriction is moderate but not if it is severe

Resistance training will not promote clinically significant weight loss  Does not seem to be effective for weight reduction in the order of 3% of initial weight and does not add to weight loss when combined with diet restriction  Increases fat free mass when used alone or with diet restriction  Increase loss of fat mass when combined with aerobic exercise compared to resistance training alone  No evidence currently exists for prevention of weight regain after weight loss or for a dose effect for resistance training and weight loss

Resistance training Benefits  Improves CVD risk factors in the absence of weight loss  Increases HDL  Decrease LDL  Decrease TG  Improves insulin sensitivity  Reduces systolic and diastolic blood pressure

References  Donelly et al. Apropiate Physical Activity Intervention Strategies for Weight Loss and Prevention of Weight Regain for Adults. Position Stand. Medicine and Science in Sports and Exercise. 2009, American College of Sports Medicine  Garber et al. Exercise for Developing and Maintaining cardiorespiratory, Musculoskeletal, and Neuromotor Fitness in Apparently Healthy Adults: Guidance for Prescribing Exercise. Position Stand. Medicine and Science in Sports and Exercise. 2011, American College of Sports Medicine

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