Exercise Prescription for Cardiovascular Fitness The Art of Exercise Prescription The art of exercise prescription is the successful integration of exercise science with behavioral techniques that result in long-term program compliance and attainment of the individual s goals. P 136 (ACSM s Guidelines) Components of Fitness Cardiorespiratory Resistance Exercise Muscular Strength Muscular Endurance Flexibility Body Composition 1
MSSE Vol 30, number 6 1998 The Recommended Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory and Muscular Fitness and Flexibility in Healthy Adults ACSM Position Stands Definitions Specificity training effects derived from an exercise program are specific to the exercise performed, muscle groups involved, ROM and energy system utilized Overload principle for a tissue or organ to improve its function, it must be exposed to a stimulus greater than it is normally accustomed to 2
Components of the Training Session Warm-up (5-20 minutes) Purpose Facilitates transition from rest to exercise Stretches postural muscles Increases blood flow to working muscle Elevates body temperature Increase joint ROM May decrease susceptibility to musculoskeletal injury May decrease occurrence of ischemia and lifethreatening arrhythmias Warm-up Protocol 5-10 min of low-intensity exercise (10-30% HRR) gradually increasing in intensity to the lower limit of the exercise prescription 5-10 min of static, dynamic, or PNF stretching Stimulus or Conditioning Phase Purpose Improve VO2max Reduce risk of CAD, diabetes, etc. Protocol 20-60 min of continuous or intermittent activity (multiple bouts of 10 minutes) Lower intensity 30 min or more 3
Cool-down Purpose Gradually decrease heart rate Prevent pooling of blood (muscle pump) Prevent post exercise hypotension - antihypertensives Combats post exercise increase in plasma catecholamines reducing risk of serious arrhythmias Cool-down Protocol Gradually decrease in intensity for 5-10 min (muscle pump) - large muscle groups Stretching Length of W-U and C-D? Depends. Time of day Temperature Medications Risk stratification Intensity of work out 4
Checking Heart Rate/RPE When? End of warm-up Reach steady state, not too late to adjust End of cool down Heart rate still elevated Hot shower Where monitor? Carotid problems at rest Brachial Radial Hand over chest (exercise only) 5
How many seconds? Rest 30 60 seconds Exercise 15 X 4 = 60 seconds 10 X 6 = 60 seconds 6 X 10 = 60 seconds Issues Accuracy 15 second count Decrease Intensity heart rate drops within 15 seconds Time to locate pulse 10 second count for exercise Start from 0 or 1? 0 - if timing is initiated simultaneously with a pulsation 1 - if a second person is keeping time or a lag between the initiation of timing and first pulsation 6
Variables That Interact to Form Exercise Prescription Frequency Intensity Time Type of Activity Type of Activity Variety Exercise all major muscle groups Reduce risk (high-impact vs nonweight bearing) of injury Increase likelihood that training effect will transfer to vocational and recreational activities Aerobic Activity Extended time Rhythmic/repetitive Large muscle groups* CWT ~ 6% increase in VO2max vs 20-25% for aerobic exercise program 7
If target heart rates are equivalent during cardiorespiratory endurance exercise and circuit weight training, why aren t the training effects the same (increase in VO 2 max)? Pressor Response Increase in SBP and DBP Q = HR X SV HR increases with CDV and WT SV NC or decrease with WT Decreased preload (venous return due to compression of vena cava) Increased afterload (due to mechanical constriction of vessels) - increased TPR decreases EF or SV) Box 7-1. Grouping of Cardiorespiratory Endurance Activities (p 144 G) Group 1 Activities that can be readily maintained at a constant intensity and interindividual variation in energy expenditure is relatively low. Desirable for more precise control of exercise intensity, as in the early stages of a rehabilitation program. Examples of these activities are walking and cycling, especially treadmill and cycle ergometry 8
Box 7-1. Grouping of Cardiorespiratory Endurance Activities Continued Group 2 Activities in which the rate of energy expenditure is highly related to skill, but for a given individual can provide a constant intensity. Such activities may also be useful in early stages of conditioning, but individual skill levels must be considered. Examples include swimming and cross-country skiing Box 7-1. Grouping of Cardiorespiratory Endurance Activities Continued Group 3 Activities where both skill and intensity of exercise are highly variable. Such activities can be very useful to provide group interaction and variety in exercise, but must be cautiously employed for high-risk, low-fit, and/or symptomatic individuals. Competitive factors must also be considered and minimized. Examples of these activities are racquet sports and basketball Determining Exercise Intensity p 145 G Individual s level of fitness: low fit, very sedentary and clinical populations can improve fitness with lowerintensity, longer- duration exercise sessions. Higher fit individuals need to work at the higher end of the intensity continuum to improve and maintain their fitness Medications (see Appendix A) that may influence HR require special attention when defining the initial target HR range and when the dose or timing is changed 9
Exercise Intensity Continued Risk of cardiovascular and orthopedic injuries is higher and adherence is lower with higher-intensity exercise programs Individual preferences for exercise must be considered to improve the likelihood that the individual will adhere to the exercise program Individual program objectives (lower BP; lower body fatness; increased VO 2max ) help define the characteristics of the exercise prescription Time 20-60 min of continuous or intermittent exercise Minimum of 10 min bouts Most train 20-30 min 70-85% HRmax or 60-80% HRR, not counting WU and CD Related to caloric expenditure goals Incidence of Injury and Time 15 min - 22% 30 min 24% 45 min 54%**** 10
Frequency Deconditioned can improve with 2 d/wk Optimal 3-5 d/wk >3 d/wk magnitude of change is smaller Exercise at Lower Intensities > 3 d/wk required to achieve adequate caloric expenditure in novice population 150-400 kcal/day in PA or Exercise ~ 1,000 kcal/wk as initial goal for sedentary Goal = 300-400 kcal/d of PA If < 5MET functional capacity 1-2 short daily sessions Incidence of Injury (Pollock et al.) 1 d/wk 0% 3 d/wk 12% 5 d/wk 39%********* If 60-80% HRR or 70-85% HRmax 3 days adequate to improve or maintain VO2max 11
Bottom Line > 30 min, 3 d/wk significantly increases risk of injury Transfer of Training Benefits (ACSM G p 157) Mode of Activity Specificity little transfer between arm and leg work with regard to submaximal or maximal exercise Also applies to lactate threshold and pulmonary ventilation Central vs peripheral changes 12
Fick Equation VO 2 = HR X SV X a-v O 2 dif Central Increase in SV Increase in Q at max Peripheral Increase a-v O 2 dif Increase number of capillaries Increase mitochondrial enzymes Increase number of mitochondria Increased myoglobin Mode of Activity Maximal heart rates will be different with different modes of activity RPE values will be specific to mode of exercise Cross training Muscle balance Risk of injury Variety Supervision? 13
Exercise for Weight Loss Rest 1.2 kcal/min 65% fat/35% CHO Energy system - aerobic Intensity and Substrate Utilization with Exercise Intensity CHO Utilization Fat Utilization Training Status Cardiorespiratory fitness burn more fat and less CHO for a given workload Why???? More mitochondria 14
Diet and Substrate Utilization Eat CHO within 8 hr of exercise Fat utilization CHO utilization Fasting burn greater %age of fats vs CHO Questions Is it better to exercise at a low intensity which burns more fats or a higher intensity which burns more CHO if weight loss is my primary goal? The facts about fat (Stanforth, UTA) 50% VO2max 50% fat/50% CHO 4.86 kcal/min 146 total kcal for 30 min Fat 73 kcal CHO 73 kcal 70% VO2max 40% fat/60% CHO 6.86 kcal/min 206 total kcal for 30 min Fat 82 kcal CHO 124 kcal 15
Answer If client can safely exercise for full exercise period at the higher intensity better for weight loss Why? Burns more total kcal Burns more fat (even though %age fat higher due to more total kcal burned) Total kcal burned more important than kcal as fat or CHO Greater EPOC (>70% VO 2 max ) Which is better for weight loss if only 30-60 minutes? Both cardio and weight training Studies show that cardiovascular exercise is not adequate to maintain FFM Equally important Resistance training burn more kcal post exercise for equivalent VO 2 and more fat Comparison of Weight Loss Options Goal: 5 pounds Exercise only Diet only Diet + Exercise Diet + Exercise + Resistance Training 16
Exercise Only 3 miles, 3 days/week 3 mi X 100 kcal/mile X 3 day/wk = 900 kcal/wk 3500 kcal/lb X 5 lb = 17,500 kcal 17,500 kcal/900 kcal/wk = 19.4 wk Diet Only Decrease caloric intake 250 kcal/day 250 kcal/day X 7 day/wk = 1,750 kcal/wk 17,500 kcal/1750 kcal/wk = 10 weeks Diet + Exercise Diet 1,750 kcal/wk Exercise 900 kcal/wk Total = 2,650 kcal/wk 17,500 kcal/2,650 kcal/wk = 6.6 weeks 17
Add Resistance Training Add 2 pounds of muscle mass Burn additional 35 kcal/day per lb of muscle 35 kcal/day X 2 = 70 kcal/day 70 kcal/d X 7 d/wk = 490 kcal/wk 490 + 2,650 (diet+exercise) = 3,140 kcal/wk 17,500 kcal/3,140 kcal/wk = 5.3 weeks What type of exercise is best for weight loss? Aerobic Exercise Improve health Improve VO2max Burns more kcal (10-13 kcal/min) What type of exercise is best for weight loss? Resistance Training Increase/preserve muscle mass Increase bone density Muscle is more metabolically active than fat (burns more kcal) Increase muscular strength and endurance Hormonal response favors higher post exercise oxygen consumption than endurance aerobic conditioning and fat burning 18
Bottom Line Both are important! Research on role of weight training and weight loss Not shown a definitive benefit alone or in combination with endurance exercise Reductions in FFM = Decrease in REE No scientific evidence Criteria for Overweight/Obesity 55-60% Adults Overweight (BMI > 25kg/m 2 ) Of this group 20-25% Adults Obese (BMI > 30 kg/m 2 ) Pattern of body fat distribution android (apple) vs gynoid (pear) Intra-abdominal fatness positively associated with hypertension, hypercholesterolemia and hyperinsulinemia 19
Energy Deficit 500-1,000 kcal/day Goal 1-2 pounds/week Reduce fat and kcal both for best results Maintenance of low fat intake important for maintenance of long-term weight loss Summary BMI >25 should reduce weight Reduce weight by minimum of 5-10% Long-term weight maintenance goal Maintenance body weight within 5 pounds of current weight Change eating and exercise behaviors Reduce intake 500-1,000 kcal/d Summary Fat <30% of energy intake Minimum of 150 min/wk of moderate intensity activity goal Long-term weight loss - 200-300 min/wk or > 2,000 kcal/wk of activity Resistance training Pharmacotherapy only for BMI > 30 or > 27 with comorbidities Behavioral intervention 20
Intensity and Heart Rate Intensity/type High intensity high impact High intensity low impact Low intensity high impact Low intensity low impact Heart Rate (bpm) % Max HR % VO2max 175 88 78 163 83 61 164 82 67 130 65 37 Ways to Increase Intensity (VO2) Intensity/Type VO2 (ml/kgmin) Heart Rate (bpm) Kcal/min Low Impact Aerobics 39.5 173 10.7 High Impact Aerobics 39.4 170 10.6 How do you increase HR and VO2? Propulsion (change center of gravity) Jump Bench As move Locomotion Change directions Lengthen lever arm Arms??????? 21
Bench Height vs Step Rate (VO2 ml/kgmin) Bench Height (inches) Step Rate (bpm) 6 8 10 12 120 21.3 25.9 29.8 34.1 128 22.6 27.1 31.6 36.0 Body Position and Energy Cost on Stairmaster (METs) Workload Level 5 7 9 11 No support 7.3 9.1 10.8 12.4 Arm Support 6.4 7.8 9.1 10.3 Lean 6.2 7.4 8.9 10.1 22