Physical Activity and Cardiovascular Disease ANDREAS PITTARAS MD Survival of the Fittest “…in the last 15 years, many epidemiological studies have shown an unequivocal and robust relationship of fitness, physical activity, and exercise to reduce overall and CVD mortality.” Balady JG, New Engl J Med 2002;346 (11):852-53 Coronary Heart Disease and Physical Activity of Work Morris JN, et al. Lancet 1953:2:1053-1120 Approximately 50% lower risk of CHD in those with physically demanding (i.e. mail carriers) vs those with sedentary occupations (i.e. desk clerks). Physical Activity and the Incidence of Coronary Heart Disease Powell KE, et al. Annu Rev Public Health 1987; 8:253-87 • 121 studies reviewed; 43 were included. • The relationship between sedentary lifestyle and increase risk of CHD is likely to be causal. Relative Risk for CAD Ann Review Public Health 1987; 8:253-87 RR 3 2.4 2.5 2.1 2 1 0 1.9 Physical Inactivity SBP>150 mm Hg TC>268 mg/dL Smoking >1 pack Population Attributable Risk by Risk Factor Population Attributable Risk (%) 50 40 30 20 10 0 TC Inactivity BP Smoking Obesity Diabetes It is Estimated that 250,000 Deaths/Year in the USA are Attributable to Lack of Regular Physical Activity Siegel PZ, at al., Weekly Reports 1991 Physical Activity Status in US Population • • • • 20% - 22% - Exercise Regularly 40% - 54% - Some Activity 24% - 40% - Sedentary 34% of pts are being counseled by physicians to begin or continue exercise. AHA Position Statement Circulation 1991:86(1):340-44 Physical inactivity an as independent risk factor for the development of CHD equal in status to the traditional risk factors of HTN, DM, Dyslipidemia and smoking. Exercise Type ? • Most information is derived from aerobic exercise studies. • Some evidence from occupational studies support that repeated busts of high energy output may offer protection against premature coronary mortality. Dynamic/Isotonic Exercise Low Intensity Aerobic FFA as Fuel High Intensity Anaerobic CHO as Fuel -Walking -Jogging -Cycling Strength Training Physiologic Adaptations to Exercise Training • Chronic exercise of proper intensity, duration and frequency imposes a demand on the body. • Consequently, the body makes appropriate and specific changes to accommodate the imposed demand. Cardiovascular Adaptations with Aerobic Exercise Decrease Increase • Rest HR & BP • LV Chamber • Rest & Exercise • EDV RPP • SV • Exercise HR & • CO BP (abs. WL) • VO2 max • ESV Cardiovascular Adaptations with Anaerobic Exercise No Change No Change • Rest HR & BP • LV Chamber ? • Rest & • EDV ? Exercise RPP • SV • Exercise HR & • CO BP (abs. WL) • VO max 2 • ESV LVH with Aerobic and Anaerobic Exercise Aerobic Anaerobic Volume Load Pressure Load Diastolic Stress Systolic Stress New Fibers in Series New fibers in parallel Chamber size Wall Thickness Eccentric LVH Concentric LVH CHD Death in Norwegian Men 40-59 years of Age (N=2,014) Lie et al. Eur Heart J ’85; 147-57 P<0.001 6 4 2 0 1 2 3 Fitness Quartiles 4 Cross-country Skiers CVD Death in Men (N=10,224) Blair et al. JAMA1989; 262:2395-2401 150 100 50 0 <7 7 8 9 METs 10 11 12+ A Prospective Study of Walking as Compared with Vigorous Exercise in the Prevention of CHD in Women Manson JE, et al., NEJM 1999;341:650-8 • • • • • N = 72,488 Female Nurses Age : 40 to 65 yrs old in 1986 Free of CVD or Cancer Follow-up: 8 yrs Incidence of Coronary Events: 645 Fatal or Non-Fatal MI Physical Activity & RR Adjusted for Confounding Factors (N=72,488) Mason JE, et al. NEJM:’99;341:650-8 1.2 P<0.001 1 0.88 0.81 0.8 0.74 0.66 0.4 1 2 3 Physical Activity Quintiles 4 5 Relative Risk for Coronary Events and Walking Pace (n=72,488) Mason JE, et al. NEJM:’99;341:650-8 Relative Risk 1.1 1 0.75 0.8 0.64 0.5 0.2 >30/mile 20-30/mile Walking Pace (min/mile) <20/mile Relative Risk for Coronary Events and Walking Time Mason JE, et al. NEJM:’99;341:650-8 RR 1.1 1 0.88 0.9 0.78 0.7 0.7 0.65 0.5 <10 min 10 to 29 30 to 59 60 to 179 Minutes Walking/Wk 180 + Relative Risk for Coronary Events and Walking Time in Women (n=72,488) Mason JE, et al. NEJM:’99;341:650-8 RR 1.1 1 0.88 0.9 0.78 0.7 0.7 0.65 0.5 <10 min 10 to 29 30 to 59 60 to 179 Minutes Walking/Wk 180 + FINDINGS • Brisk Walking for 100-200 min/week at a Pace of <20 min/mile or <13 min/km. Reduces the Risk for Coronary Events in Women by 30 to 40 Percent. • Similar Caloric Expenditure Yields Similar Reductions in Risk for Coronary Events. Are Exercise Health Benefits Long-Lasting? The Harvard Alumni study (n=16,936) has shown that Ex-Varsity athletes retained lower risk for CHD only if they maintained a physically active lifestyle throughout life. Paffenberger et al., Am J Epidemiol 1978 108(3):161-175 Relative Risk of CHD & Aerobic Activity in Men (N=51,529) Tanasescu M, et al. JAMA:’02;288:1994-2000 RR P<0.001 1.1 1 0.87 0.9 0.79 0.7 0.58 0.5 None <30 min/Wk 30-60 min/wk >60 min/wk Survival for Fit & Unfit Men (n=9,777) Blair et al, JAMA 1995;273:1093-97 Survival Probability 1 Unfit to Fit 0.9 0.8 0.7 44% Reduction in Risk Unfit to Unfit 0.6 0 4 8 12 Follow-up Interval (yrs) 16 18 How Much Physical Activity? How Much Exercise? • Not an easy Question • Exercise Intensity, Duration and Frequency must be considered, as well as the interaction. • Caloric expenditure is one approach. • Intensity still may play an independent role. Physical Activity and All –Cause and CVD Mortality in Women >65 yrs Gregg EW, et al. JAMA’03;289:2379--86 Relative Risk CVD 1 1 1 0.77 0.73 0.7 0.7 0.68 0.65 0.62 0.6 0.58 0.4 <163 163-503 504-1045 Kcal/wk 1046-1906 >1907 Weekly Energy Expanded and Relative Risk of CHD in Men (n=7,337) Relative Risk Lee, I-Min et al. Circulation 2003;107:1110-16 1 * 0.9 0.84 0.8 0.7 0.5 <1000 1000-2499 Kcal/Week 2500+ Age-adjusted First MI Rates by Physical Activity (n=16,963) Paffenbarger et al., Am J Epidem. 1978;108(3):161-75 80 MI/10,000 person-yrs Total 60 Non-Fatal 40 Fatal 20 0 <500 500-999 1000-1999 2000-2999 3000-3999 Physical Activity ndex in Kcal/ Week 4000+ Exercise Intensity and Relative Risk of CHD in Men (n=7,337) Relative Risk Lee I-Min, et al. Circulation 2003;107:1110-16 1 0.98 0.9 0.75 0.6 <3 METs 3-6 METs Kcal/Week >6 METs Exercise Intensity and Relative Risk of CHD in Men (n=7,337) Lee I-Min, et al. Circulation 2003;107:1110-16 Relative Risk 1 0.81 0.8 0.62 0.6 0.5 None Moderate Vigorous Very Vigorous Relative Risk of All-Cause Death and Exercise Capacity Myers J et al. NEJM 2002;346:793-801 RR of Death 5 4.5 4.2 4 3 3 2.4 2.2 2 1.7 1.7 1.25 1 1 1 <6 METS 6-7.9 METS 8-9.9 METS 10-12.9 METS >13 METS 0 1 2 3 Quintiles of Exercise Capacity 4 5 Survival Curves for Normal and CVD Patients According to Exercise Capacity Myers J et al. NEJM 2002;346:793-801 Conclusions Myers J et al. NEJM 2002;346:793-801 • Exercise Capacity is a more powerful predictor of mortality for CVD than other established risk factors. • A linear reduction in mortality. For each 1 MET increase in exercise capacity, a 12%, decrease in mortality was observed. Exercise Capacity and Risk of Death in Women Gulati M, et al. Circulation 2003;108:1554-59 Hazard Ratio of Death 3.5 3.1 2.5 1.9 1.5 2 FRS-adjust 1.6 1 0.5 <5 MET 5-8 MET >8 MET Age-adjust Exercise Capacity and Risk of Death in Women Conclusions Gulati M, et al. Circulation 2003;108:1554-59 • Exercise capacity is a strong and independent predictor of all-cause mortality in asymptomatic women, even after adjusting for traditional cardiac risk factors. • For each 1 MET increase in exercise capacity, a 17%, decrease in mortality was observed. Exercise Threshold for Health Benefits METs <4 – 5 7 10 ? • Kcal/wk Threshold Fast walk 6 km/hr 500 - 1000 Running 10 km/hr 3,000 • 120 min/wk • 240 min/wk 750 - 1050 1500-2100 1,500 3,000 • Intensity Exercise in Patients with Risk factors and/or Chronic Disease Age-Adjusted CVD Death Rates &CHD Risk Factors (n=26,980) Blair, et al. JAMA 1996 51 Death Death Rate Rate 60 27.5 50 46 46 51 40 40 30 10 20 0 22.5 46 10 23 24 23Low 0 Low 13.2 27.5 24 20 12.6 4.2 Moderate 10 3.6 High Cardiorespiratory Fitness 4.2 3.6 Moderate High 2 12.61 6.5 22.5 3 3 13.2None 6.5 2 1 None Relative Risk of All-Cause Death and Exercise Capacity Myers J et al. 2002;346:793-801 RR of Death 2.5 >8 Mets 5-8 Mets <5 Mets 1.6 1.5 1.5 1.3 1 1.35 1.3 1 1 1 1 0.5 HTN DM Smoke BMI>29 C>220 mg/dl CV Events and Physical Activity in Diabetic Women (n=5125) Hu F, et al. Ann Intern Med :’01;134;96-105 Relative Risk 1.1 1 0.93 0.82 0.7 * 0.54 0.3 <1 1-1.9 2-3.9 Hours/Wk 4-6.9 Body Weight/ Obesity Relative Risk for Physical Activity & BMI, Adjusted For Risk Factors Mason JE, et al. NEJM:’99;341:650-8 RR 1 1 >29 N=72,488 <29 0.88 0.82 0.79 0.8 0.71 0.69 0.65 0.65 0.64 0.6 0.54 0.4 1 2 3 Physical Activity Quintiles 4 5 FINDINGS • Brisk Walking for 100-200 min/week at a Pace of <20 min/mile or <13 min/km. Reduces the Risk for Coronary Events in Women by 30 to 40 Percent. • Similar Caloric Expenditure Yields Similar Reductions in Risk for Coronary Events. Relative Risk of All-Cause Death and Exercise Capacity Myers J et al. 2002;346:793-801 RR of Death 5 CVD Normal 4.5 4.2 4 3 3 2.4 2.2 2 1.7 1.7 1.25 1 1 1 <6 METS 6-7.9 METS 8-9.9 METS 10-12.9 METS >13 METS 4 5 0 1 2 3 Quintiles of Exercise Capacity Conclusions Myers J et al. 2002;346:793-801 • Exercise Capacity is a more powerful predictor of mortality for CVD than other established risk factors. • A linear reduction in mortality. For each 1 MET increase in exercise capacity, a 12%, decrease in mortality was observed. STROKE The NIH Consensus Development Panel on Physical Activity and CVD JAMA ‘96;276:241-46 Data are inadequate to determine whether stroke incidence is affected by physical activity or exercise training. Physical Activity and Risk of Stroke in Women Hu FB, et al , JAMA 2000;283:2961-67 • • • • N=72,488 Female Nurses with no CVD or Cancer at Baseline Age: 40-65 years Follow-up: 8 years (560,087 person-years) 407 Strokes • 258 Ischemic • 67 Subarachnoid Hemorrhages • 42 Intracerebral & 40 of Unknown type Multivariate Relative Risk of Total Strokes Relative Risk 1.1 P=0.005 0.9 1 0.98 0.7 0.82 0.74 0.66 0.5 1 2 3 MET Quintiles 4 5 Multivariate RR for Ischemic Strokes Relative Risk 1 P=0.003 0.8 1 0.87 0.6 0.83 0.76 0.52 0.4 1 2 3 MET Quintiles 4 5 Multivariate Relative Risk of Total Strokes by Walking Activity Relative Risk P=0.01 1 0.8 1 0.6 0.76 0.78 0.7 0.66 0.4 0-0.5 0.6-2.0 2.1-3.8 METS 3.9-10 10+ Multivariate Relative Risk of Ischemic Strokes by Walking Activity Relative Risk p=0.02 1 0.8 1 0.6 0.77 0.75 0.69 0.6 0.4 0-0.5 0.6-2.0 2.1-3.8 METS 3.9-10 10+ RR of Total Strokes by Walking Pace Relative Risk 1 1 Age-Adjusted 1 Multivariate P<0.001 0.81 0.8 0.66 0.6 0.49 0.36 0.4 0.2 <2mph 2-2.9 mph 3+ mph Relative Risk of Hemorrhagic Strokes by Walking Pace Relative Risk 1 1 0.9 P<0.02 Age-Adjusted P<0.06 Multivariate 0.82 0.73 0.7 0.57 0.5 0.5 0.3 <2mph 2-2.9 mph 3+ mph Findings and Conclusions Sedentary women who became active in middle to late adulthood had significantly lower risk for: • Total Strokes : 27% - Age-adjusted 20% - Multivariate • Ischemic Strokes: 38% - Age-adjusted 30% - Multivariate Findings and Conclusions • • Walking pace is strongly associated with risk of stroke, Independent of the number of hours spent walking. Comparable magnitudes of risk reduction with equivalent energy expenditures from walking and vigorous activity. Cardiac Function HTN Dyslipidemia Physical Activity Body Fat DM Type II ?? Endothelial Function Hypertension Kokkinos P., et al. Cardiology Clinics 2001;19(3):507-516 Average Reduction in BP: Active: 10.5/7.6 mm Hg Controls: 3.8/1.3 mm Hg BP Changes with Exercise Kokkinos ,Pittaraset al. NEJM 1995;333:1462-7 mm Hg 0 -2 -4 -6 -8 SBP DBP P<0.05 -10 16 weeks 32 weeks BP Changes with Exercise mm Hg 0 -2 -4 2 Wks -6 2 Wks -8 16 Wks 16 Wks -10 -12 SBP DBP Relative Risk of All-Cause Death and Exercise Capacity in Hypertensive Patients RR of Death Myers J et al. 2002;346:793-801 2.2 2 1.7 1.3 1.2 1 0.7 0.2 >8 MET 5-8 MET <5 MET LVMI at Baseline and 16 Weeks Kokkinos, Pittaras et al. NEJM 1995;333:1462-7 * p<0.05 170 163 155 * 143 140 125 Baseline 16 weeks Wall Thickness at Baseline and 16 wks Kokkinos, Pittaras et al. NEJM 1995;333:1462-7 mm 15 * p<0.05 * 14 13 * 12 11 PW IVS Left ventricular hypertrophy is a powerful and independent predictor of cardiovascular events in patients with and without obstructive coronary disease. Ghali JK et al., 1992; Ann Intern Med 1992;117:831-36 Koren MJ et al., 1991; Ann Intern Med 1991;114:345-52 Casale PN, et al., Ann Intern Med 1986;105:173-78 LV Mass and Stroke Odds Ratio 7 Unadjusted Adjusted 6.14 6 5.49 5 4 2.8 2.72 3 2 2.5 1.59 1 1 1 0 1 2 3 Quartiles of LV Mass 4 LVH, Physical Activity and Risk of Stroke Adjusted Odds Ratio 5 4.5 4 3.5 3 2.5 2 1.5 1 1.59 1.78 Total Men 0.5 1.42 1.64 1.79 Women 40-60 yrs >60 yrs 0 LVH, Physical Activity & Risk of Stroke Odds Ratio 4 3.48 3 2 1 0.66 1 0.4 0 No LVH LVH SBP Following Aerobic Training Kokkinos et al, AJC 1997 p<0.01 220 219 219 200 * 199 198 * 180 187 171 160 * 140 138 131 120 Rest 6-Min 9-Min * Peak May mitigate the hemodynamic load during daily physical activities. Attenuate the development and/or progression of LVH. Heart Failure Skeletal Muscle Atrophy Muscular Changes Patient Adapts Sedentary Lifestyle Diminished Aerobic Capacity Cardiorespiratory Changes Neurohormonal Changes Kokkinos et al.. AHJ:140(1): 2000 All Cardiac Event Survival for HF Patients Belardinelli et al, Circulation ‘ 99;99:1173-82 1 Trained Survival 0.8 0.6 0.4 Untrained 0.2 0 0 200 400 600 800 Time (Days) 1000 1200 1400 1600 Hospitalization for Heart Failure Belardinelli et al, Circulation ‘ 99;99:1173-82 Survival probability 1 Trained 0.8 0.6 Untrained 0.4 0 200 400 600 800 Time (Days) 1000 1200 1400 1600 Cardiac Deaths for HF Patients Belardinelli et al, Circulation ‘ 99;99:1173-82 1 Trained Survival 0.8 0.6 Untrained 0.4 0.2 0 200 400 600 800 Time (Days) 1000 1200 1400 1600 Lipid & Lipoprotein Metabolism Changes in Lipids & Lipoproteins with Exercise and Diet in Men Wood et al., NEJM 1991;325:461-6 % Change 20 Control Diet Diet+Ex 10 0 HDL-C -10 TG -20 -30 LDL-C Changes in Lipids & Lipoproteins with Exercise and Diet in Women % Change 20 Wood et al., NEJM 1991;325:461-6 Control Diet Diet+Ex 10 0 TG -10 -20 LDL-C HDL-C Is There A Dose-Response Relationship? A dose-response relationship between HDL-C Levels and weekly distance run or weekly caloric expenditure is supported by most studies. HDL-C and Km Run/Week: A dose-Response Relationship Kokkinos P., et al. Arch Intern Med ‘95;155:415-20 mg/dL N=2,906 * p<0.001 56 53 * 53 51 49 47 46 0-3 4 to 10 11 to 16 Km/Week 17 to 22 23 to 32 33+ Is There An Exercise Threshold? The exercise-induced changes in lipid metabolism are likely the result of the interaction among exercise: Intensity, Duration, Frequency and Length of Training. It is also likely that an exercise threshold exists for each of these exercise components. HDL-C and Weekly Distance Kokkinos P., et al. Arch Intern Med ‘95;155:415-20 mg/dL 58 N=2,906 * 56 p<0.001 54 53 53 17-22 23-32 * 51 50 49 47 46 0-3 4 to 10 11 to 16 Km/Week 32+ Carbohydrate Metabolism The Association between Cardiorespiratory Fitness and Impaired Fasting Glucose and Type II DM Wei M, et al., Ann Intern Med 1999;130:89-96 • • • • • N = 8,633 Non-Diabetic Men Age : 30 to 79 yrs old 7,511 Had Normal Fasting Blood Glucose Follow-up: 6 yrs 149 Developed DM and 593 Developed Impaired Fasting Glucose Cardiorespiratory Fitness & Relative Risk for Type II Diabetes Wei M, et al. Ann Intern Med:1999;130:89-96 Relative Risk p<0.001 3.7 3.5 2.5 1.7 1.5 1 0.5 Low Fitness Levels Moderate High Cardiorespiratory Fitness & Relative Risk for Impaired Fasting Glucose Wei M, et al. Ann Intern Med:’99;130:89-96 Relative Risk 2 1.9 p<0.001 1.5 1.5 1 1 0.5 Low Moderate Fitness Levels High Cardiorespiratory Fitness & RR for Impaired Fasting Glucose & Type II Diabetes in Women (n=338) Relative Risk 4.85 p<0.001 5 4 2.7 3 2 1 1 0 Low Moderate Fitness Levels High Cumulative Incidence of Diabetes Diabetes Prevention Program Research Group NEJM 346 (6) 393-403 Cumulative Incidence of DM (%) 40 Placebo 30 Metformin 20 Lifestyle 10 0 0.5 1 1.5 2 2.5 Follow-up Interval (yrs) 3 3.5 4 Plasma Fasting Glucose Diabetes Prevention Program Research Group NEJM 346 (6) 393-403 Plasma Glucose (mg/dl 115 Placebo 110 Metformin Lifestyle 105 100 0 0.5 1 1.5 2 Follow-up Interval (yrs) 2.5 3 3.5 4 Glycosylated Hemoglobin Diabetes Prevention Program Research Group NEJM 346 (6) 393-403 Glycosylated Hemoglobin (%) 6.3 Placebo 6.1 Metformin 5.9 Lifestyle 5.7 0 0.5 1 2 Follow-up Interval (yrs) 3 4 Conclusions • Lifestyle changes and treatment with metformin both reduced the incidence of DM in persons at high risk. • Lifestyle intervention was more effective than metformin. Number of pts need to be treated for 3 yrs to prevent 1 case of DM is 6.9 for the lifestyle intervention and 13.9 for metformin. • Plasma Glucose Levels Before & After Aerobic Training Plasma Glucose (mg/dl) Smutok et al. Metabolism ‘93 200 Pre-Training 180 160 * * 140 Post-Training 120 100 0 30 60 90 Minutes After Glucose Ingestion 120 Plasma Glucose Levels Before & After Strength Training Plasma Glucose (mg/dl) Smutok et al. Metabolism ‘93 ‘ 200 Pre-Training * 180 * 160 * 140 Post-Training 120 100 0 30 60 90 Minutes After Glucose Ingestion 120 Plasma Insulin Levels Before & After Aerobic Training Plasma Insulin (U/ml) Smutok et al. Metabolism ‘93 105 Pre-Training 85 * 65 * 45 Post-Training 25 5 0 30 60 90 Minutes After Glucose Ingestion 120 Plasma Insulin Levels Before & After Strength Training Plasma Insulin (U/ml) Smutok et al. Metabolism ‘93 105 Pre-Training 85 65 * 45 * Post-Training 25 5 0 30 60 90 Minutes After Glucose Ingestion 120 Body Weight/ Obesity Relative Risk for Physical Activity & BMI, Adjusted For Risk Factors Mason JE, et al. NEJM:’99;341:650-8 RR 1.2 1 N=72,488 >29 <29 1 0.88 0.82 0.79 0.8 0.71 0.69 0.65 0.65 0.64 0.6 0.54 0.4 1 2 3 Physical Activity Quintiles 4 5 Cardiorespiratory Fitness & CVD Mortality in Men (N=25,714) Relative Risk 5 Wei M, et al.JAMA:’99;282(16);1547-53 5 4.5 Fit Unfit 4 3.1 3 2 1.5 1.6 1 1 0 (Normal) BMI<25 BMI 25-29.9 (Over WT) BMI 30+ (Obese) CVD Mortality Predictors in Normal WT Men (BMI 18.5-24.9) Wei M, et al.JAMA:’99;282(16);1547-53 Relative Risk 4 3.1 3 2.6 2.1 2.2 2 1.4 1 0 TC Smoke DM HTN Low Fit CVD Mortality Predictors in Overweight Men (BMI 25-29.9) Wei M, et al.JAMA:’99;282(16);1547-53 Relative Risk 5 4.5 3.9 4 3.3 3 3.4 2.8 2 TC Smoke HTN DM Low Fit CVD Mortality Predictors in Obese Men (BMI >30) Wei M, et al.JAMA:’99;282(16);1547-53 Relative Risk 5.5 4.9 5 4.7 4.5 4.4 4.5 3.5 Smoke HTN TC DM Low Fit These findings suggest that it is as important for a clinician to assess the fitness status of patients, (especially obese) as it is to assess blood glucose, TC, HTN and smoking habits. Exercise Recommendations • Aerobic Activity 3-5 times/wk • • • • Brisk Walk to Slow Jog 60% to 80% of PMHR 100 to 200 minutes/week 1200 to 2400 Kcal/Wk LVMI at Baseline and 16 Weeks in Patients with LVH g/m2 170 Kokkinos, Pittaras et al. New Engl J Med 1995;333:1462-7 * p<0.05 163 * 150 143 Baseline 130 16 weeks Wall Thickness at Baseline and 16 wks Kokkinos, Pittaras et al. New Engl J Med 1995;333:1462-7 mm 15 14.9 * p<0.05 * 14 14 13.3 13 * 12.3 12 11 PW IVS How Much Physical Activity ? • • • • • Do something Choose something you enjoy Start Low & Progress Slowly Increase duration by 1-2 min/wk Be Consistent (2-5 times/week) Goal: 100-200 minutes/week Exercise Training is Governed By Three Principles • Specificity • Overload • Reversibility The Specificity Principle Biological Systems will Make Specific Adaptations to Accommodate an Imposed Demand ! SPECIFICITY Aerobic Anaerobic • Long Duration (>10 min) • Low Intensity (<85% of PMHR) • ATP via TCA Cycle • FFA as Fuel • Short Duration (<5 min) • High Intensity ( >90% of PMHR) • ATP via Glycolysis • CHO as Fuel The Overload Principle The performance of a Biological System will Improve Only If the Demand Imposed upon it is Greater than the System is Currently Accustomed. Overload Principle Frequency, Duration and/or Intensity Must be Increased Periodically. Reversibility Principle Training adaptations diminish if stimulation (training) is discontinued for a length of time (12 -90 days). Exercise Components • Frequency - Times/Wk • • • Duration Intensity Length - Min/Session - How Hard - How many Wks Frequency • 2- 5 Times per Week • Exercise Every Other Day • Multiple Short Daily Sessions (5-10 min) for Those with Functional Capacity < 3 METS Duration • 20-60 Minutes/Session of Continuous Aerobic Activity • Multiple Daily Sessions (~ 10 min) for Those with Functional Capacity < 3 METs. • Slow, Progressive Increase Length of Training Most Exercise Benefits Are Evident Within 12 Weeks of Consistent Training. ACSM Exercise Intensity Classifications METS %PMHR • Low <4 35-59 • Moderate 4-6 60-79 • High >6 > 80 Exercise For Overweight & Obese Patients Exercise Modality that does not Impose Excessive Orthopedic Stress (walking, stationary bike, aquatic exercises). Exercise Intensity for Patients on Chronotropic Medications Base Exercise intensity on 50% to 80% of Peak HR achieved during ETT. METs & Kcal for 30 Minutes of Select Physical Activities (80-kg person) Activity • • • • • • Fast Walk Jog (12 min/mile) Bike (Stationary) Health Club Dancing Stair Climbing METs 5 8 7 7 5 5 Kcal 200 320 280 280 200 200 Contraindications & Recommendations for Exercise • Complete Physical • • • • Resting BP< 190/105 mm Hg Exercise BP <240/120 mm Hg Exercise SBP drop >10 mm Hg (baseline) Unable to complete 5 METs (ETT) or climb a flight of stairs without severe SOB or symptoms. Gill et al. JAMA 2000 Relative Risk of Onset of MI with Physical Activity 8 7 Willich et al. NEJM '93 6 Relative Risk 4 1.3 2 0 Inactive Active Relative Risk of Onset of MI with Physical Activity Mittleman et al. NEJM '93 107 90 Relative Risk 60 20 30 8 2.4 0 0 1 to 2 3 to 4 5+ The relative MI Risk for a 50-yr-old Non-smoking, Non-diabetic Man during a given hour is 1 in 1 million. If this man were sedentary and engaged in heavy physical exertion during that hour, his risk would increase 100 times or 1 in 10,000. Framingham Heart Study