Exercise Prescription for Cardiovascular diseases Dr. Leung Tat Chi, Godwin Specialist in Cardiology 27 April 2008 Prevention of Atherosclerotic Vascular Disease by Physical Exercise Physical activity reduces the incidence of CAD Physical inactivity is a major CAD risk factor The relation is strong, with the most physically active subject is generally demonstrated CAD rates half those of the most sedentary group Independent of other risk factors Not protective in later years without lifelong physical activity Benefit seen in middle age and older age groups Powell KE, Thompson PD, Caspersen CJ, et al. Physical activity and the incidence of coronary heart disease. Annu Rev Public Health. 1987;8:253-287 Reduction of Atherosclerotic Risk Factors Physical activity both prevents and treats establish atherosclerotic risk factors: – – – – – Elevated blood pressure Insulin resistance Glucose intolerance Elevated triglyceride concentration, low HDL-C Obesity Exercise + weight reduction >>>> LDL-C and increase HDL Thompson et al, Exercise and Physical Activity in Cardiovascular Disease. Circulation June 24, 2003; 107:3109-3166 Response of Blood Lipids to Exercise Training Meta-analysis of 52 exercise training trials of >12 weeks Include 4700 patients Change in lipid profile – HDL-C increase 4.6% – Reduction in LDL-C by 5.0% – Reduction in TG by 3.7% Leon AS, Sanchez O. Meta-analysis of the effects of aerobic exercise training on blood lipids. Circulation. 2001;104(suppl II):II-414-415. Abstract. Response of Blood Pressure to Exercise Training 44 randomized controlled trials include 2674 patients Average change in blood pressure – SBP decrease by 3.4 mmHg – DBP decrease by 2.4 mmHg Hypertensive patient – SBP decrease by 7.4 mmHg – DBP decrease by 5.8 mmHg Normotensive patient – SBP decrease by 2.6 mmHg – DBP decrease by 1.8 mmHg BP drop is not dose related Fagard RH. Exercise characteristics and the blood pressure response to dynamic physical training. Med Sci Sports Exerc. 2001;33(6 suppl) Blood Pressure Reductions as Little as 2 mmHg Reduce the Risk of Cardiovascular Events by up to 10% Meta-analysis of 61 prospective, observational studies 1 million adults 12.7 million person-years 7% reduction in risk of ischemic heart disease mortality 2 mmHg decrease in mean systolic blood pressure 10% reduction in risk of stroke mortality Lewington S, et al. Lancet. 2002;360:1903–1913 Lifestyle modification Modification Recommendation Physical activity Engage in regular aerobic physical activity such as brisk walking (at least 30 mins per day, most days of the week) Moderation of alcohol consumption SBP reduction 4-9mmHg Limit consumption to no more 2-4mmHg than 2 drinks (e.g., 24 oz beer, 10 oz wine, or 3 oz 80-proof whiskey) per day in most men and to no more than 1 drink per day in women and lighterweight persons Lifestyle modification Modification Recommendation SBP reduction Weight Reduction Maintain normal BW (BMI 18.5-24.9kg/m2) 520mmHg/10kg Adopt DASH eating plan Diet rich in fruits, vegetables, and low-fat diary products with a reduced content of dietary cholesterol as well as saturated and total fat 6-14mmHg Dietary sodium restriction Reducing dietary sodium to 2-8mmHg no more than 100 mmol/day (2-4g Na or 6g NaCl) Effect of Exercise-based Cardiac Rehabilitation on Cardiac Events Outcome Mean Difference 95% Cl Statistically Significant? Exercise-only intervention Total mortality -27% -2% to –40% Yes Cardiac mortality -31% -6% to –49% Yes Nonfatal MI -4% -31% to +35% No Comprehensive rehabilitation Total mortality -13% -29% to +5% No Cardiac mortality -26% -4% to –43% Yes Nonfatal MI -12% -30%-+12% No Cl indicates confidences intervals. Cls not including zero are statistically significant. •Meta analysis include 51 randomized trials •Include 8440 patients: CABG, PTCA, MI, angina, middle-age men •Supervised exercise for 6 months, follow up 2 years later Jolliffe JA, Rees K, Taylor RS, et al. Exercise-based rehabilitation for coronary heart disease. Cochrane Database Syst Rev. 2001(1):CD001800 The Exercise Training Intervention after Coronary Angioplasty Randomised 118 patients after coronary revascularization 6 months of exercise training vs usual care Trained patients significant increases in peak VO2 (26%) Quality of life parameters increases in 27% Fewer cardiac events (11.9% vs 32.2%) Hospital readimissions (18.6% vs 46%) Residual coronary stenosis decrease by 30% Recurrent cardiac event reduced by 29% BelardinelliR, Paolini I, Cianci G, et al. Exercise Training Intervention after Coronary Angioplasty: the ETICA trial. J Am Coll Cardiol., 2001;37:1891-1900 Risk Cardiac rehabitation programs – Cardiac arrest: 1 in 117000 (patient-hours of participation) – Nonfatal MI: 1: in 220000 – Death : 1: 750000 Aerobic Activity Muscle-Strengthening Activity Recommendation Frequency Intensity Duration Healthy adults, 2007. (ACSM/AHA Recommendation) A minimum of 5 d/wk for moderate intensity, or a minimum of 3 d/wk for vigorous intensity Moderate intensity between 3.0 and 6.0 METS; vigorous intensity above 6 METS Older adults, 2007 (ACSM/AHA Recommendation) A minimum of 5 d/wk for moderate intensity, or a minimum of 3 d/wk for vigorous intensity Moderate intensity at 5 to 6 on a 10point scale; vigorous intensity at 7 to 8 on 10point scale Frequency Number of Exercises Sets and repetitions Accumulate at At least 2 least 30 min/d d/wk of moderateintensity activity, in bouts of at least 10 min each; continuious vigorous activity for at least 20 min/d 8-10 exercises involving the major muscle groups 8-12 repetitions Accumulate at At least 2 least 30 min/d d/wk of moderateintensity activity, in bouts of at least 10 min each; continuious vigorous activity for at least 20 min/d 8-10 exercises involving the major muscle groups 10-15 repetitions Flexibiltiy/ Balance At least 2 d/wk flexibiltiy; for those at risk of falls, include exercises to maintain or improve balance Aerobic Activity Muscle-Strengthening Activity Recommendation Frequency Intensity Duration Frequency Number of Exercises Sets and repetitions Hypertension, 2004 (ACSM Recommendation) Most, preferably all days per week Moderate intensity at 40 <60% of VO2max reserve (vigorous intensity acceptable for selected adults) Accumulate 30 - 60 min/d of moderateintensity activity, in bouts of at least 10 min each; 2-3 d/wk (resistance training an adjunct to aerobic activity) 8-10 exercises involving the major muscle groups 1 set of 815 repetitions (more than 1 set acceptable for selected adults) Cholesterol, 2001, National Cholesterol Education Program Most days of the week, preferably daily Moderate intensity At least 30 min/d Musclestrengthening activities recommended as beneficial Flexibiltiy/ Balance Flexibility regarded as beneficial Aerobic Activity Muscle-Strengthening Activity Recommendation Frequency Intensity Duration Frequency Coronary artery disease, 2001, AHA (aerobic recommendation) At least 3 d/wk Moderate intensity at 40 60% of HR reserve (vigorous intensity as tolerated at 6085% of HR reserve) At least 30 min Cardiovascular disease, 2000, AHA (flexibility and resistance training recommendation) A minimum of 5 d/wk for moderate intensity, or a minimum of 3 d/wk for vigorous intensity Moderate intensity at 5 to 6 on a 10point scale; vigorous intensity at 7 to 8 on 10point scale Accumulate at At least 2 least 30 min/d d/wk of moderateintensity activity, in bouts of at least 10 min each; continuious vigorous activity for at least 20 min/d Number of Exercises Sets and repetitions Flexibiltiy/ Balance 8-10 exercises involving the major muscle groups 10-15 repetitions At least 2 d/wk flexibiltiy; for those at risk of falls, include exercises to maintain or improve balance Hypertension and Exercise Position Stand (Evaluation) Severity Secondary cause CV risk factors Target organ damage (TOD) CVD complications Exercise is a major lifestyle modification needed to prevent, treat and control hypertension Hypertension and Exercise Position Stand (Evaluation) Supervised exercise stress test – High intensity exercise program (VO2 R >60%) – Patients with TOD/DM or BP >180/110 before engaging in moderate-intensity exercise (VO2R 40 to 60%) – Patients with CVD (stroke, heart failure, IHD) Avoid high intensity exercise (vigorous program best initiated at dedicated rehabilitation centre) Special Consideration Beta-blockers and diuretics impair the ability to regulate body temperature. S/S of heat illness Adequate hydration Proper clothing Optimal times of the day Beta blockers can alter submaximal and maximal exercise capacity Alpha blockers, CCB, vasodilators Provoke hypotensive episodes after abrupt cessation of activity Extend the cool-down period Diuretics increase the potential for dehydration Hypertension and Exercise Position Stand Emphasis on aerobic activity. VO2R 40 to 60%. RPE 12-13. Avoid high-intensity resistance training (lower intensity, higher repetitions). Clients should maintain hypertensive medications, if prescribed. Do not exercise if resting SBP > 200 mm Hg or DBP > 115 mm Hg. Maintain BP <220/105 during exercise Begin pharmacological treatment prior to starting exercise program if BP > 160/100 Resistance training/ Valsalva maneuver Forced expiration against a closed glottis Increase in intrathoracic pressure leading to decreased venous return and potentially reduced cardiac output At the release of the “strain,” venous return is dramatically increased, increasing cardiac output and elevation of BP Symptoms of lightheadedness or dizziness may occur if cardiac output is reduced. With relaxation, individuals may experience headache while pressure remains elevated. In patients with heart disease, symptoms of myocardial ischemia may ensue as a result of elevated BP and increased myocardial work. Adherence Education regarding the importance of regular exercise for BP control Especially responsive if information comes from their personal physician Knowledge of the immediate BP-lowering effects of exercise (up to 22 hr) (PEH) Cardiac rehabilitation Core components – Medical assessment – Nutrition counseling – Risk factor management (lipid, DM, weight, smoking) – Psychosocial management – Activity counseling and exercise training Cardiac rehabilitation Phase I – Inpatient Phase II – Up to 12 weeks of ECG monitored exercise Phase III – Clinical supervision Phase IV – No ECG, medical supervision Cardiovascular System Assessment Patients with known coronary artery disease should undergo a supervised evaluation of the ischemic response to exercise, ischemic threshold, and the propensity to arrhythmia during exercise. In many cases, left ventricular systolic function at rest and during its response to exercise should be assessed. Physical Activity/Exercise and Diabetes; Diabetes care, vol. 27, supplement 1, January 2004 Exercise testing Integral component of the rehab process – Establishment of appropriate specific safety precautions – Guide training intensity – Target exercise training heart rates – Initial levels of exercise training work rates – Risk stratification Should be performed on all cardiac patients entering an exercise training program Exercise prescription for individuals with CAD (Risk Stratification) Mildly increased risk – Preserved LV systolic function (EF > 50%) – Normal exercise tolerance for age > 50 years old 50 to 59 60 to 60 >70 > 10METS >9METS >8METS >7METS – Absence of exercise induced ischemia – Absence of hemodynamically significant stenosis of a major coronary artery (>50%) – Successful revascularization Exercise prescription for individuals with CAD (Risk Stratification) Substantially increased risk – Impaired LV systolic function (<50%) – Evidence of exercise-induced myocardial ischemia – Hemodynamically significant stenosis of a major coronary artery (>50%) Medically Supervised Exercise Moderate to High risk subjects – – Medical supervision required until safety established ECG and BP monitoring (usually > 12 sessions) Low risk subjects – Benefit from medically supervised programs – Safe Group dynamics ECG monitoring (useful during the early phase, 6 – to 12 sessions) Rehabilitation in Coronary Heart Disease • Mainly endurance training • at an intensity of 50 (-60) -75% of symptomlimited VO2max (or heart rate reserve) for 30 minutes 3-4 times weekly (minimum), full benefit is obtained with 5-6 times/week • Resistance training in addition • at an intensity of 30-50% (up to 60-80%) of 1 RM (one repetition maximum), 12-15 repetitions, 1-3 sets twice weekly Outpatients exercise program Setting a safe upper limit for Intensity – Moderate intensity exercise (40 to 60% VO2max) – Brisk walking, treadmill, cycle, stair-climbing, rowing machine – Initial intensity 40 to 60% of heart rate reserve Can be increased to 85% (high intensity) if tolerated – RPE 11 to 13 (between fairly light to somewhat hard) Duration may be increased as appropriate after safe activity levels established Intensity may be increased as heart rate response to exercise decreases with conditioning Exercise prescription without exercise test Initial exercise intensity – 2 to 3 METs 1 to 2 mph, 0% grade on treadmill 100 to 300 kg.m.min-1 (12.5- 50W) on cycle ergometer – RPE: 11-13 – Gradual increments of 0.5 to 1.0 METs as tolerated – Target heart rate 20 beats/min above standing rest – Frequency 30 – 45 minutes per day 5 d/wk, Exercise prescription in the presence of ischemia Inappropriate for those with angina < 3METS Aim to increase anginal threshold Prolonged warm up and cool Upper body exercises may precipitate angina more readily Heart rate and work rate below the identified threshold of ischemia Should be a minimum of 10 beats/min below the heart rate at which the abnormality occurs Intermittent, shorter duration-type on a more frequent basis Home exercise rehabilitation Lower cost Convenience Promote independence Comparable safey and efficacy Good communication between patients and staff required Heart Failure Benefits of exercise – Functional capacity, improved leg blood flow and oxidative capacity, neurohormones, autonomic tone Initiated at a low to moderate level (25 to 60% of VO2max) VO2max determined by direct gas exchange measurements Careful supervision and monitoring Brief training session Lengthened warm up and cool down RPE: 11 to 14 Safety and efficacy of resistance training not well established After cardiac procedure CABG – Avoid upper body exercise for 3 months PCI – Resume exercise no sooner than 5 to 7 days – Catheterization access sites should be healed Pacemakers and implantable cardioverter defrillators Type and settings of pacemaker should be noted Avoid high intensity resistance exercise Fixed-rate pacemakers – Activity intensity must be gauged by other methods RPE ICD – Limit target heart rate at least 10 to 15 beats/min lower than the threshold discharge rate AHA Scientific Statement: Recommendations for the Acceptability of Recreational (Noncompetitive) Sports Activities and Exercise in Patients With Genetic CVD GCVD – HCM, LQTS, Marfan syndrome, ARVC, Brugada syndrome Recreational sports are categorized with regard to high, moderate and low levels of exercise Graded on relative scale (from 0 to 5) for eligibility – 0 to 1: indicating generally not advised or strongly discouraged – 4 to 5: indicating probably permitted – 2 to 3: indicating intermediate and to be assessed clinically in an individual basis AHA Scientific Statement: Recommendations for the Acceptability of Recreational (Noncompetitive) Sports Activities and Exercise in Patients With GCVDs Intensity Level HCM LQTS Marfan Syndrome ARVC Brugada Symdrome Basketball 0 0 2 1 2 Full court 0 0 2 1 2 Half court 1 1 0 1 1 Body building 0 0 1 0 0 Ice hockey 0 2 2 0 2 Racquetball/squash 1 1 1 1 1 Rock climbing 0 0 2 0 2 Running (downhill) 2 2 2 1 1 Skiing (cross-country) 2 3 2 1 4 Soccer 0 0 2 0 2 Tennis (singles) 0 0 3 0 2 Touch (flag) football 1 1 3 1 3 Windsurfing 1 0 1 1 1 High Recommendations for Physical Activity and Recreational Sports Participation for Young Patients with Genetic Cardiovascular Diseases, Circulation. 2004; 109:2807-2816) AHA Scientific Statement: Recommendations for the Acceptability of Recreational (Noncompetitive) Sports Activities and Exercise in Patients With GCVDs Intensity Level HCM LQTS Marfan Syndrome ARVC Brugada Symdrome Baseball/softball 2 2 2 2 4 Biking 4 4 3 2 5 Modest hiking 4 5 5 2 4 Motocycling 3 1 2 2 2 Jogging 3 3 3 2 5 Sailing 3 3 2 2 4 Surfing 2 0 1 1 1 Swimming (lap) 5 0 3 3 4 Tennis (doubles) 4 4 4 3 4 Treadmill/stationary bicycle 5 5 4 3 5 Weightlifting (free weights) 1 1 0 1 1 Hiking 3 3 3 2 4 Moderate Recommendations for Physical Activity and Recreational Sports Participation for Young Patients with Genetic Cardiovascular Diseases, Circulation. 2004; 109:2807-2816) AHA Scientific Statement: Recommendations for the Acceptability of Recreational (Noncompetitive) Sports Activities and Exercise in Patients With GCVDs Intensity Level HCM LQTS Marfan Syndrome ARVC Brugada Symdrome Bowling 5 5 5 4 5 Golf 5 5 5 4 5 Horseback riding 3 3 3 3 3 Scuba diving 0 0 0 0 0 Skating 5 5 5 4 5 Snorkeling 5 0 5 4 4 Weights (non-free weights) 4 4 0 4 4 Brisk walking 5 5 5 5 5 Low Recommendations for Physical Activity and Recreational Sports Participation for Young Patients with Genetic Cardiovascular Diseases, Circulation. 2004; 109:2807-2816) Case study Mr. Wong is a 50-year old male, sales representative who travels often BP 150/90 mmHg Medications: atenolol 50mg daily, lisinopril 10mg daily Resting HR: 60/min 170cm, 84kg , BMI 29 His brother just suffered from MI at age 40. Concerned about his health Want to do start exercise and lose weight Evaluation Classify client according to Risk Stratification Criteria – ACSM/ ACP/ACCVPR/ AHA Identify Major Coronary Artery Disease Risk Factors Identify signs or symptoms suggestive of cardiopulmonary disease Identify secondary risk factors – Obesity, alcohol consumption, stress levels Consider the following criteria during your evaluation: – – – – – – Age and gender Moderate Vs vigorous exercise program Physician present during testing Submaximal or maximal graded exercise test Type of test (treadmill, leg ergometer, step) Absolute and relative contraindications to exercise testing What recommendations in reference to medical examination and testing prior to participation in an exercise program? Hypertension and Exercise Position Stand (Evaluation) Supervised exercise stress test – High intensity exercise program (VO2 R >60%) – Patients with TOD/DM or BP >180/110 before engaging in moderate-intensity exercise (VO2R 40 to 60%) – Patients with CVD (stroke, heart failure, IHD) Avoid high intensity exercise (vigorous program best initiated at dedicated rehabilitation centre) Questions Please write an initial exercise prescription Any adjustments and practical tips in patients with HT? Aerobic Activity Muscle-Strengthening Activity Recommendation Frequency Intensity Duration Frequency Number of Exercises Sets and repetitions Hypertension, 2004 (ACSM Recommendation) Most, preferably all days per week Moderate intensity at 40 <60% of VO2max reserve (vigorous intensity acceptable for selected adults) Accumulate 30 - 60 min/d of moderateintensity activity, in bouts of at least 10 min each; 2-3 d/wk (resistance training an adjunct to aerobic activity) 8-10 exercises involving the major muscle groups 1 set of 815 repetitions (more than 1 set acceptable for selected adults) Cholesterol, 2001, National Cholesterol Education Program Most days of the week, preferably daily Moderate intensity At least 30 min/d Musclestrengthening activities recommended as beneficial Flexibiltiy/ Balance Flexibility regarded as beneficial Special Consideration Beta-blockers and diuretics impair the ability to regulate body temperature. S/S of heat illness Adequate hydration Proper clothing Optimal times of the day Beta blockers can alter submaximal and maximal exercise capacity Alpha blockers, CCB, vasodilators Provoke hypotensive episodes after abrupt cessation of activity Extend the cool-down period Diuretics increase the potential for dehydration Exercise Prescription 5 days per week (F) 40 to 60% VO2 max/HRR reserve (I) 12-14 RPE 30 – 60 min per session (T) Rhythmical & aerobic, large muscle activities (running, jogging, cycling …etc.) (T) Case Study M/60 Recently diagnosed to have type 2 DM, put on Daonil BP 160/90 mmHg on metoprolol 50mg bd Half pack a day smoking habit due to stress of his job Cholesterol level: 6.2mmol/l , HDL 0.90 mmol/l, LDL 3.8mmol/l TG: 2.4 mmol/l No regular exercise No signs or symptoms of cardiopulmonary disease A constellation of cardiovascular risk factors related to hypertension, abdominal obesity, dyslipidemia, and insulin resistance Certain drugs used to treat hypertension may accelerate the appearance of new-onset diabetes. In particular, both β blockers and diuretics have been implicated in this effect. ALLHAT – In high risk hypertensive patients, the diuretic, chlorthalidone, was 43% more likely than the ACEI, lisinopril, to produce diabetes, but was also 18% more likely than the calcium channel blocker, amlodipine, to produce this adverse effect. HOPE – The development of new diabetes was reduced by 34% (p<0.001) in the ramipril-treated group. LIFE (Losartan Intervention For Endpoint Reduction in Hypertension) – The ARB, losartan, was associated with a 25% relative risk reduction in new-onset diabetes when compared with the β blocker, atenolol VALUE (The Valsartan Antihypertensive Long-term Use Evaluation) – Valsartan, was associated with 23% RRR in new-onset diabetes when compared with the calcium channel blocker, amlodipine. ARB/ACEI may have positive effects on insulin action and potentially plays a meaningful role in protecting high-risk hypertensive patients from developing diabetes. Medications Metoprolol changed to ACE inhibitors/ ARB Metformin Statin Will you subject patient to exercise stress test before writing exercise prescription? Exercise stress test METS achieved: 8 VO2max = 28 ml kg-1 min-1 Peak heart rate: 160 beats per minute Peak blood pressure of 200/88 mmHg. No exercise induced ischemia Questions Please write an initial exercise prescription Any adjustments and practical tips in patients with DM and HT? Exercise prescription Address each of the following – Aerobic endurance – Strength training – Flexibility Include each of the following in your prescription frequency times/day, days/week Intensity HRR, %VO2max, %HRmax, %1RM, %MVC, etc Duration warm-up, cool-down, exercise component, rest between sets, etc Mode of exercise types of exercise, stretching techniques, resistance training, etc Rate of progression Target heart rate zone HRR (40%) – = (160-60) x 0.4 + 60 – = 100 – (60%) – =120 Exercise Intensity – Concepts of METs and Ex HR MET (metabolic equivalent) – A unit of metabolic equivalent, or MET, is defined as the number of calories consumed by an organism per minute in an activity relative to the Basal metabolic rate 1 MET is equivalent to a metabolic rate consuming 3.5 milliliters of oxygen per kilogram of body weight per minute. 1 MET is equivalent to a metabolic rate consuming 1 kilocalorie per kilogram of body weight per hour. Simple Estimation of Ex Intensity Low Intensity: 3-5 METs Moderate Intensity: 4-7 METs High Intensity: 8-12 METs e.g. A 75 kg man plays basketball game for 30 min, Kcal = ? Kcal = METs x duration x Wt/60 = 8 x 30 x 80/60 = 8 x 30 x 80/60 = 320 KCal METs: a multiple of the resting rate of oxygen consumption (of a seated individual at rest) 1 MET = 3.5 ml kg-1 min-1 VO2 Compendium of Physical Activities (MSSE, 1993: 71-80) Target VO2 What will be the intensity exercise? Lower range: – 28-3.5 x 0.4 + 3.5= 13.3 ml kg-1 min-1 Higher range: – 18.2 ml kg-1 min-1 Recommended work rate VO2 = (0.1 (speed)) + 1.8 (speed) (grade) + 3.5ml kg-1 min-1 – For treadmill grade 2.5% Speed = 13.3 ml kg-1 min-1/0.145 =91.7m/min or 5.5 kph @2.5% Recommendation Health professionals should personally engage in an active lifestyle References Exercise standards for testing and training: a statement for healthcare professionals from the American Heart Association. Circulation. 2001;104:1694-1740 Exercise and physical activity in the prevention and treatment of atherosclerotic cardiovascular disease: AHA scientific statement. Circulation. 2003;107:3109-3116 Recommendations for Physical Activity and Recreational Sports Participation for Young Patients with Genetic Cardiovascular Diseases, Circulation. 2004; 109:2807-2816 ACSM’s guidelines for exercise testing and prescription. 7th edition 36th Bethesda Conference. Eligibility recommendations for competitive athletes with cardiovascular abnormalities. JACC 19 April 2005 Recommendations for preparticipation screening and the assessment of cardiovascular disease in masters athletes. Circulation. 2001;103:327-334. Physical activity and public health in older adults: Recommendation from the American College of Sports Medicine and the American Heart Association. Circulation. 2007;116:000-000 ACSM Position Stand. Exercise and Hypertension. hypertension. Med. Sci. Sports Exerc. 36:533–553, 2004. Resistance Exercise in Individuals With and Without Cardiovascular Disease: 2007 Update Circulation. 2007;116:572-584