Physical activity in Healthy Adults and in Weight ManagementAlexandra M. Rivera VegaAssistant Professor Physical Medicine and RehabilitationUAMSARiveravega@uams.edu

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

Cardiorespiratory

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 ≥ 500-1000MET/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 150-250 min/wk

• 1200-2000 kcal/wk

• 12-20 miles/wk

PA Promote Weight Lost

• PA <150 min/wk= minimal weight lost

• PA>150 min/wk=2-3 kg

• PA 225-420min/wk=5-7.5kg

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

http://www.nyc.gov/html/doh/downloads/pdf/tcny/takethestairs.pdf

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

Thanks!