Chapter 16 Exercise Prescriptions for Health and Fitness
Dose-Response for Exercise: FITT-VP principle
- Includes Frequency, Intensity, Time, Type - Volume Frequency x intensity x time - Progression Transition from easier to harder exercise
Muscular strength and flexibility are important components of a complete fitness program
- Increasing and maintaining strength - Additional health benefits
U.S. Physical Activity Guidelines (2008):
- Individuals can realize the health-related benefits of physical activity by doing between 150 and 300 minutes of moderate-intensity physical activity per week, or 75 to 150 minutes of vigorous intensity physical activity per week, or some combination of the two. 150 minutes of moderate-intensity physical activity or 75 minutes of vigorous intensity physical activity is the minimum goal The range of physical activity (150-300 minutes) indicates that more health-related benefits are realized by doing additional activity (i.e., more is better). Physical activity can be done in multiple intermittent bouts (e.g., 10 min each) to meet the goal.
Sequence of Physical Activity: Games and Sports
- Intermittent higher-intensity activities within THR range
General Guidelines for Improving Fitness: Warm-up, stretch and cool-down, stretch
- Light exercise and stretching performed at beginning and end of exercise session
Regular participation in physical activity associated with:
- Lower rates of all-cause mortality, total CVD, and CHD incidence and mortality - Increased weight loss and reduced weight regain - Lower incidence of obesity, type 2 diabetes, and metabolic syndrome - Lower risk of colon and breast cancer - Improved ability to complete activities of daily living and reduced risk of falls - Reduction in depression and cognitive decline - Favorable changes in cardiovascular disease risk factors
Exercise Prescription for CRF: Time (duration)
- Must be considered with intensity Greater time required at lower intensities - Many sedentary people can more easily complete longer duration exercise at lower intensity
Acute response
- Occur with one or several exercise bouts but do not improve further
Strength Training: Single Versus Multiple Sets: ACSM recommendation
- One set of 8-10 exercises (major muscle groups) - 8-12 reps per set - 2-3 sessions per week
The effect (response) of the amount of a drug (dose)
- Potency Relatively unimportant characteristic - Slope How much change in effect comes from a change in dose - Maximal effect Efficacy - Variability Effect varies between and within individuals - Side effect Adverse effect
Sequence of Physical Activity: Walking
- Recommended activity for sedentary - Start at a comfortable speed for 15 minutes - Gradually increase duration and speed
Moderate physical activity results in reducing health- related problems
- Risk associated with PA is low
General Guidelines for Improving Fitness: Screening
- Risk of cardiovascular complications is related to degree of pre-existing cardiac disease
Dose-Response for Exercise: Response
- Specific changes VO2 max - Health-related changes
Sequence of Physical Activity: Jogging
- Start by adding some running when walking - Gradually increase speed/duration of running
General Guidelines for Improving Fitness: Progression
- Start with light- to moderate-intensity activity - Then increase duration and/or intensity Walk----->walk/jog----->jog Increase about 10%
6. For a person with a maximal heart rate of 180 b•min-1 and a resting heart rate of 70 b•min-1, calculate a target heart rate range by the Karvonen method and the percent of maximal HR method.
- Subtract resting HR from maximal HR to obtain HRR - Take 60% and 80% of HRR - Add each HRR to resting HRR to obtain THR range - 180(max HR) - 70(resting HR) = 110 (HHR) - 110 (HHR)x.60 = 66 - 110 (HHR)x.80 = 88 - 66+70 = 136 - 88+70 = 158 - THR 136-158 beats per min
Determining Target Heart Rate Range: Direct
- THR range determined from maximal GXT - HR at 60-80% VO2 max
The ACSM/AHA recommendation (2007):
- To promote and maintain health, all healthy adults aged 18 to 65 years need moderate-intensity aerobic (endurance) physical activity for a minimum of 30 min on five days each week or vigorous-intensity aerobic physical activity for a minimum of 20 min on three days each week. - Included resistance training 8-10 exercises, 8-12 reps, two or more non-consecutive days per week
Strength Training: Max Strength
- Untrained: four sets at 60% 1-RM, three days/week - Trained: four sets at 80% 1-RM, two days/week - Athletes: eight sets at 85% 1-RM, two days/week
Physical activity and health
- Volume of physical activity is most important variable linked to health - Risk of chronic diseases reduced by 20-40% Greatest gains in those who went from no activity to some activity - Some physical activity is better than none Even if recommendations aren't met - More activity is better for health outcomes Balanced by increased risk for adverse outcomes with too much activity
Sequence of Physical Activity
- Walking - Jogging - Games and Sports
Dynamic, large muscle activities
- Walking, jogging, running, swimming, cycling, rowing, dancing
7. Recommend an appropriate progression of activities for a sedentary person wishing to become fit.
- progression of physical activities is from walking to jogging to games Start with light- to moderate-intensity activity Then increase duration and/or intensity Walk----->walk/jog----->jog Increase about 10%
2. From a public health standpoint, why is there so much attention paid to increasing a sedentary person's physical activity by a small amount rather than recommending strenuous exercise?
- small changes in physical activity result in large health benefits with only minimal risk
Exercise Prescription for CRF: Frequency
- ≥5 days/week for moderate intensity exercise - ≥3 days/week for vigorous intensity exercise - Minimum of 2 days/week - Gains level off after 3 to 4 sessions/week - Higher frequencies associated with increased risk of injury
Pattern of Responses to Exercise: Types
-Acute -Rapid -Linear -Delayed
How does resistance training compare w/ aerobic training in reducing risk of disease?
-Resistance training increases and maintains strength and decreases in body weight and fat mass with comparable increases in fat-free mass. -Both offer a strong protective role in the prevention of non-insulin-dependent diabetes mellitus. -Both support optimal changes in body composition to successfully attain weight management goals, which in turn reduces the risk of disease.
9. What is the recommended resistance-training program for untrained adults.
60-70% of 1-RM for 8-12 reps 1-3 sets with 2-3 min rest between sets 2-3 days per week
Strength and Flexibility Training: In Summary
A logical progression of physical activities is from walking to jogging to games. The progression addresses issues of intensity, as well as the risk of injury. For many, walking may be their only aerobic activity. Strength and flexibility activities should be included as a regular part of an exercise program.
Dose-Response for Exercise: In Summary
An exercise dose reflects the interaction of the intensity, frequency, and duration to yield the volume of exercise. The response to an exercise intervention can include both functional changes (e.g., an increase in VO2 max) and health outcomes (e.g., lower blood pressure), independent of each other.
Exercise Prescription for CRF: ACSM recommendation
- 3-5 sessions per week - 20-60 min per session - Intensity of 40-89% HRR or VO2R Moderate intensity: 40-59% HRR Vigorous intensity: 60-89% HRR - Should result in volume of 500-1000 MET-min per week
Moderate intensity PA
- 3-6 METs - May be vigorous for deconditioned subjects
Additional Progression Guidelines: Novice
- 60-70% of 1-RM for 8-12 reps - 1-3 sets with 2-3 min rest between sets - 2-3 days per week
Additional Progression Guidelines: Inter.
- 60-70% of 1-RM for 8-12 reps - multiple sets with 2-3 min rest between sets - 3-4 days per week
Additional Progression Guidelines: Adv.
- 80-100% of 1-RM - Multiple sets with 2-3 min rest between sets - 4-6 days per week
Exercise Prescription for CRF: In Summary
- A sedentary person needs to go through a health status screening before participating in exercise. - Exercise programs for previously sedentary persons should start with moderate-intensity activities (walking) and focus on increasing frequency and duration to gain additional health benefits before intensity is increased. - The optimal characteristics of an exercise program are: intensity = 60-80% VO2 max; frequency = 3-4 times per week; duration = minutes needed to expend about 200-300 kcal. - The THR range, taken as 60-80% HRR, or 70-85% of maximal HR, is a reasonable estimate of the proper exercise intensity.
Physical activity
- Any form of muscular activity - Can reduce the risk of death from all causes - Rduces risk factor for coronary heart disease
Vigorous-intensity PA was associated with reduced risk of CHD compared to lower intensities
- CHD risk factors also lower
Exercise Prescription for CRF: Intensity
- Describes the overload needed to bring about a training effect - CRF improvements at 60-80% of VO2 max Lower in those with low initial fitness level - Prescribed using target heart rate range
Strength and Flexibility Training: ACSM Recommendation
- Dynamic exercises - Done on routine basi
The ACSM/CDC recommendation (1995):
- Every U.S. adult should accumulate thirty minutes or more of moderate-intensity (3-6 METs) physical activity on most, preferably all, days of the week
Dose-Response for Exercise: Dose
- Frequency (F) Days per week, times per day - Intensity (I) %VO2 max, % maximal heart rate Rating of perceived exertion Lactate threshold - Time (T) Number of minutes of exercise - Type (T) Resistance, cardiovascular endurance Swimming, running, rowing
Higher intensity PA associated with
- Greater impact on CHD risk factors - Less sick leave
Determining Target Heart Rate Range: Indirect
- Heart rate reserve (Karvonen) method Subtract resting HR from maximal HR to obtain HRR Take 60% and 80% of HRR Add each HRR to resting HRR to obtain THR range - Percentage of maximal HR Take 70% and 85% of maximal HR as THR range - Use RPE scale in addition to HR RPE of 12-17 is about 40-89% HRR
Risk of cardiac arrest in vigorously active men
- Higher risk during exercise - Lower overall (exercise + rest) risk
Vigorous-intensity PA was more beneficial for altering CHD risk factors
- In some cases, equal to moderate intensity PA
Environmental Concerns
Environmental conditions can elevate exercise heart rate - Heat and humidity Increases blood circulation to skin - Altitude Decreases oxygen bound to hemoglobin Adjust exercise intensity in adverse environments - Use THR range as a guide for intensity Exercise in cold is typically safe - Dress appropriately - Avoid dangerous cold/wind conditions
4. What is the difference between "exercise" and "physical activity"?
Exercise is a subset of physical activity w/ a planned goal of improving/maintaining fitness, while physical activity is "any form of muscular activity".
5. List the optimal frequency, intensity, and duration of exercise needed to achieve an increase in cardiorespiratory function.
Frequency- Minimum of 2 days/week ≥5 days/week for moderate intensity exercise ≥3 days/week for vigorous intensity exercise Intensity- 60-80% of VO2 max Duration- Must be considered with intensity Greater time required at lower intensities Many sedentary people can more easily complete longer duration exercise at lower intensity
General Guidelines for Improving Fitness: In Summary
In previously sedentary subjects, small changes in physical activity result in large health benefits with only minimal risk. Strenuous exercise increases the risk of a heart attack during the activity, but reduces the overall (rest + exercise) risk of such an event. Moderate-to-high levels of cardiorespiratory fitness confers additional health benefits and increases one's ability to engage in recreational activities.
Strength Training: Multiple Sets
Multiple sets more effective for improving strength
1. What are the practical implications of classifying physical inactivity as a primary risk factor?
Physical inactivity can lead to: - coronary heart disease (CHD)
Intro: In Summary
Physical inactivity has been classified as a primary risk factor for coronary heart disease. Regular participation in physical activity can reduce the overall risk for those who smoke or who are hypertensive. Those who increase their physical activity and/or cardiorespiratory fitness have a lower death rate from all causes compared to those who remain sedentary.
Strength Training: Single Sets
Single set sufficient when maximal strength gain is not the primary goal
8. Why is it important to monitor heart rate frequently during exercise in heat, humidity, and at altitude
The THR acts as a guide to adjust exercise intensity in adverse environments such as high temperature and humidity, or altitude. A decrease in exercise intensity will counter the effects of high environmental temperature and humidity to allow one to stay in the target HR zone
Environmental Concerns: In Summary
The THR acts as a guide to adjust exercise intensity in adverse environments such as high temperature and humidity, or altitude. A decrease in exercise intensity will counter the effects of high environmental temperature and humidity to allow one to stay in the target HR zone.
3. What is the risk of cardiac arrest for someone who participates in a regular physical activity program?
The risk of cardiac arrest in habitually active men is higher during vigorous activity, however the overall risk of cardiac arrest in vigorously active men is only 40% of the risk in sedentary men.
Dose-Response: In Summary
To realize the health-related benefits of physical activity, adults should do between 150 and 300 minutes of moderate-intensity physical activity per week, or 75 to 150 minutes of vigorous intensity physical activity per week, or some combination of the two. Resistance training (8-10 exercises, 8-12 reps) should be done on two or more non-consecutive days per week.
Benefits of Resistance Training: Diagram
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Dose-Response Relationship for Exercise: diagram
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Dose-Response of Physical Activity Related to All-Cause Mortality: diagram
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Examples of Walking and Jogging Programs: Diagram
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Intensity, Duration, and Frequency of Exercise and VO2 Max and Risks: Diagram
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Relative Exercise Intensity Based on Exercise Capacity: diagram
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Relative Risk of Death Among Different Fitness Levels: Diagram
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Target Heart Rate Range Determined From GXT: Diagram
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The Relationship Between Dose of a Drug and Effect: diagram
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