2Topic Outline The Role of Physical Activity in Obesity Management for: Weight lossWeight loss maintenancePrevention of obesityReducing general health risksMechanisms of ActionCurrent Recommendations for Physical Activity in Obesity TherapyTranslating Physical Activity Recommendations into Increased Physical Activity in Patients
3Weight Loss: What Works? Effect of Physical Activity Without Diet on Body Weight Loss1ModeFrequencyWeight LossEpstein and WingWalk/run2 - 5x/wk0.09 kg/wkBallor and KesseyWalk/run/cycle3 - 4x/wk0.1 kg/wkGarrow and SummerbellHadjiolva, et alVariousDaily(10 hrs/day)1.8 kg/wkLee, et alMilitary Training5x/wk0.6 kg/wk1Zachwieja JJ. Endocrinol Metab Clin North Am 1995;25:
4Physical Activity Usually Does Not Increase Short-Term Diet-Induced Weight Loss Blonk 1994Sweeney 1993-15-10-5Weight Loss (kg)*Diet onlyDiet + exerciseWadden 1997Ross 1996Marks 1995Ross 1995Bertram 1990Each study ranged from 4 to 6 months*P < 0.05 vs diet-only groupWing. Med Sci Sports Exerc. 1999;31(suppl):S547.
5Physical Activity and Weight Loss Most studies suggest a reasonable amount of physical activitydoes not produce weight lossExercise alone to 0.1 kg/weekDose response relationshipdoes not significantly increase initial weight loss over what is obtained by caloric restriction alone
6Dr. Steve Blair - Cooper Institute “Do not judge the impact of physical activity by weight loss”Dr. Steve Blair - Cooper InstituteSeptember 20, 2004
7Weight Loss Maintenance: What Works? Adapted from Pavlou KN, et al. Am J Clin Nutr. 1989;49:
8Weight Loss Maintenance: What Works? ***n = 84n = 102n = 87n = 76n = 80Jeffery RW et al AJCN 2003;78:684-9.
9Physical Activity and Weight Loss Maintenance Data from case studies, correlation studies and randomized control trails have all concluded that high levels of physical activity facilitate maintenance of weight loss long-term
10Prevention: What Works? Freshman and Sophomore Womenat the University of KansasDonnelly J, Jacobsen D, Hill JO. Archives of Internal Medicine 163: , 2003.
11Freshman and Sophomore Women at the University of Kansas 225 minutes/week prevented weight gain in women at risk (2.3 kg/16 months)225 minutes produced a weight loss in men at risk (5.2 kg/16 months)Women 439 kcal/session (5.4 kcal/kg)Men 667 kcal/session (6.7 kcal/kg)Donnelly J, Jacobsen D, Hill JO. Archives of Internal Medicine 163: , 2003.
12Physical Activity and General Health Moderate levels of cardiorespiratory fitness substantially reduce mortality risks associated with overweight and obesityModerate levels of cardiorespiratory fitness can be developed in 30 minutes of activity at least 5 days per week
13HERITAGE Family Study * Pre-Training Post-Training 100908070605040302010High TG Low HDL-C High BP High Glucose High WC Metabolic SyndromePre-TrainingPost-Training*Prevalence of individual risk factors before and after 20 wk of aerobic exercise training in the HERITAGE Family Study among 105 participants with the metabolic syndrome at baseline. *P < 0.05 pre- versus post-training.Katzmaryck PT, Leon AS, Wilmore JH, et al. Med Sci Sports Exerc, 2003; Vol. 35, No. 10, 1703–1709.
14Why the difference in impact for physical activity between weight loss and weight loss maintenance?
15Differences Between Weight Loss and Weight Loss Maintenance Maintenance of Weight LossTime limitedRequires a negative energy balanceReduced caloric intake is criticalPhysical activity not required for successCommonLife-longRequires energy balance at a reduced body weightPhysical activity is critical for successRare
16Why Is Physical Activity Critical Mechanism of ActionWhy Is Physical Activity Criticalfor Long-Term Success?Makes it more likely for patients to remain in Energy Balance at a reduced body weightWhy? Possibilities include:Direct compensation for diet indiscretionsPrevent or attenuate metabolic efficiency associated with weight lossImproved self-efficacy or moodImproved satiety/hungerAllows better “physiological” matching of intake and expenditure to occur
17Potential Effects of Increasing Physical Activity vs Potential Effects of Increasing Physical Activity vs. Decreasing Intake on Encouraging Physiological Energy BalanceObesity ConduciveEnvironmentEnergy BalanceEnergy IntakePhysiologicalControl MaximizedActivityBAIntakeCCognitiveControl RequiredEnergy Expenditure
18Physical Activity Recommendations: How Much is Enough? A Common Patient Misconception“30 minutes of physical activity every day is all I need to do to manage my weight”
19How Much is Enough? Current PA Recommendations Minimal public health recommendations to improve health related outcomes30 min moderate activity most days of the week (150 minutes/week)CDC - Centers for Disease ControlACSM - American College of Sports MedicineSG - Surgeon GeneralMaximize weight loss and prevent weight regain45-60 minutes/dayIOM - Institutes of Medicine60-90 minutes/dayIASO - International Assoc for Study of Obesity60 minutes/day (300 minutes/week)ACSM - American College Sports MedicinePreventing general weight gainUnclear
20Weight Loss Maintenance: How Much is Enough? Schoeller et al, AJCN 1997;66:551-6.
21Weight Loss Maintenance: How Much is Enough? Women in the physically active group gained the least weight after reaching their target for weight lossRetrospective analysis: Threshold of 11 kcal/kg of body wt/day80 minutes of moderate intensity activity or minutes of vigorous activitySupports that body weight is better regulated at a higher energy fluxSchoeller et al, AJCN 1997;66:551-6.
22Average Energy Expended in Physical Activity in the NWCR Klem et al, AJCN 1997;66:
23What About Intensity?Studies suggest the intensity of physical activity may have limited impact on weight control when total energy expenditure (TEE) is fixedHigh levels of energy expenditure (EE) improve weight managementSo if vigorous intensity results in greater EE weight loss outcomes will improveSo if moderate intensity results in greater EE weight outcomes will improveModerate intensity provides health benefits while presenting low to moderate health risks
24Planned vs Lifestyle Activity Planned Activity- completed in a discrete period of time, moderate to high intensity30 to 60 minutesWalking, swimming, bikingLifestyle Activity- completed during everyday tasksParking further away, taking stairs, walk to meetings
25Mean Changes in Body Weight for Lifestyle Activity vs Aerobic Exercise Anderson et al. JAMA 1999; 281: 337.
26Long vs Short BoutsMultiple short bouts are as effective as one long bout and perhaps may facilitate efforts to increase activityHelps address the barrier of perceived lack of timeMultiple short bouts increase adoption of physical activity during first 6 monthsLong-term impact is less clearJakicic JM et al. JAMA 1999;282(16):Jacobsen DJ et al. Int J Sports Med 2003;24:
27Physical Activity - The “Magic Pill” What Patients Want… Currently availableSafe, cheap and effectiveIncrease my “metabolism”Burn fat as fuelAllow me to eat more food without gaining weightMake me “healthier”
28How to Get Your Overweight Patients to Be More Active
29How to Get Your Overweight Patients to Be More Active For many individuals, starting a structured exercise program is not possibleTherefore: Implement small lifestyle changes to increase daily physical activityPark at end of lot when driving to storeOnly have one phone in house so patient has to walk to use itFind the stairs!Walk to a co-worker’s office at work instead of calling on the phoneUse elevators only if going up more than 2 floorsDecrease sedentary activity
30Lifestyle Activity Program Wear a pedometer every day for a week to determine baselineIncrease steps by 500 steps/day /weekUltimate goal 10, ,000 steps/day500 steps = 5 minutes walking moderateHelps set goals and gives instantaneous feedbackDo all those little changes add up?
32Then What?After these lifestyle alterations are in place, start on a structured exercise planStart slow - perhaps as little as min of activity per day (whatever they enjoy and will continue to do)Total amount of activity is what counts
33ConclusionsPhysical activity recommendations of 30 minutes most days of the week are based on improving cardiovascular health - a good initial or minimal goalminutes of physical activity may be what is necessary to prevent regain following a weight loss (long-term goal)Risk factors associated with Metabolic Syndrome improve with physical activityHow to get patients to do what we know it takes is the real problemLifestyle changes and short bouts of activity in sedentary individuals may be the place to startGradual increase over years may be necessaryLong-term adherence is the most important goal