Prof. Stanley HUIProf. Stanley HUI

許世全教授許世全教授香港中文大學體育運動科學系 副教授香港體適能總會 副主席美國運動醫學學院 院士

Exercise PrescriptionExercise PrescriptionForFor

Chronic DiseasesChronic Diseases

運動處方 運動處方 – – 特殊族群特殊族群

ACSM Guidelines for Exercise Testing and Prescription

(ACSM 7th Ed., Chapters 7-10)

Guideline for Exercise Testing and Prescription

(ACSM 7th Ed., Chapters 7-10)

Principles of Training• Overload - Work harder than the body is

accustomed to.Frequency - number of times per weekIntensity - level of the effort at any given

time; speed, weight, hills, water resistance, etc.

Duration - time, reps/sets in weight training

Principles of Training (Continued)

FIT Principle - Frequency, Intensity, TimeFrequency and duration together are often referred to

as training volume. In weight training volume is often reps/sets (volume per exercise session).

• Specificity - Adaptations that occur are specific to the type of training performed.

Principles of Training (Continued)

• Progression Gradually increase the overload in an exercise

program over time.Prevent possible injury and frustration.NOTE: Increase training volume first, then

intensity.Table 7-4, Page 154

• Reversibility - Training adaptations (improvements) will be lost if training is stopped for a prolonged period of time. In general, the faster the adaptation occurred, the

sooner it will be lost once training stops.

Aerobic Fitness

Target Heart Rate, METs, and RPE

1. Target Heart Rate Target HR range = 55/65 – 90% HRmax Heart Rate Reserve (Karvonen) Method:

o Target HR range = 40/60 – 80% HRR

THRR = [(HRmax – RHR) x .40/.50 and .85] + RHR

Target VO2:o VO2 Reserve =

(% intensity)(VO2max – VO2rest) + VO2rest

Aerobic Fitness (Continued)

Target Heart Rate, METs, and RPE (Continued)2. Metabolic Equivalents (METs):

One MET = 3.5 ml/kg/min (VO2) Target METs = Target VO2 (ml/kg/min)/3.5

ml/kg/min Target VO2 based on reserve (R) concept:

VO2R = (% intensity)(VO2max – VO2rest) + VO2rest Note: current ACSM recommendations suggest

using % of VO2R instead of % of VO2max

Table 7.3, Pages 152 –153

Aerobic Fitness (Continued)

Target Heart Rate, METs, and RPE (Continued)

3. RPE – Rating of Perceived Exertion (Borg Scale) Category Scale (6-20) and Category-Ratio

Scale (0-10); Table 4-6, Page 79. Guideline of 12 – 16 on CS, 3 – 6 on C-

RS; also see Table 7.2, page 150.

Rate of Perceived Exertion Scale. (RPE)

Aerobic Fitness (Continued)

Target Heart Rate, METs, and RPE (Continued)• General Points for THR, METs, and RPE:

These all represent exercise intensity.THR and RPE are most commonly used.METs (target VO2) can be problematic because:

• METs cannot be easily monitored in many exercise settings.• METs will vary with skill level and conditioning in various

exercises (e.g., running vs. swimming).THR can be problematic if it is based upon predicted

HRmax (220 – age; error of ± 10 bts/min)

Aerobic Fitness (Continued)

Target Heart Rate, METs, and RPE (Continued)

• Caloric Expenditure GuidelinesAnother guide for exercise prescriptionExpend 150 – 400 Kcal/day (150 for low

fitness level)Caloric cost of exercise:

Kcal/min = [METs x 3.5 x BW (kg)]/200Note: Caloric expenditure takes into account

all three components of overload (FIT).

Aerobic Fitness (Continued)

Exercise Duration and Frequency• Duration

The duration is dependent upon the intensity.To achieve health/fitness benefits, ACSM

recommends 20 – 60 min of continuous or intermittent (10-min bouts) of exercise at 60 – 80% of HRR (VO2R).Higher intensity can allow for less time.Lower intensity should be accompanied by a

longer duration.

Aerobic Fitness (Continued)

Exercise Duration and Frequency (Continued)

• FrequencyACSM recommends 3 – 5 days per week.If intensity is low, greater than 3 days/week

may be necessary to achieve weight loss goals.

Muscular Fitness

• ACSM guidelines and the ACSM Position Stand regarding recommendations for muscular fitness programming focuses on health fitness for the general population.Recommendations reflect minimum

requirements to develop muscular strength, endurance, and flexibility.

These recommendations are not best suited for athletic performance enhancement.

Muscular Fitness (Continued)

• Muscular fitness incorporates strength, endurance and flexibility (the text separates flexibility into its own category).

• Strength improvements are greater with near maximal intensity (resistance) and fewer repetitions.

• Endurance improvements are greater with lower intensity and more repetitions.

• For general fitness improvements, exercise prescription develops both strength and endurance. 8 to 12 repetitions that result in fatigue (ages < 50 – 60 yrs). 10 – 15 repetitions that result in fatigue (ages > 50 – 60 yrs).

Muscular Fitness (Continued)

• Exercise prescription recommendations for muscular strength and endurance:Exercises – sufficient number to train all major

muscle groups (8 to 10 exercises).Sets – 1 set sufficient to develop strength and

endurance.Repetitions – 8 to 12 that result in volitional

fatigue (intensity) (10 to 15 for older adults; lower intensity).

Frequency – 2 to 3 d/wk.Overall Goal – time efficiency. High drop out rate

for general fitness programs if muscular training program is longer than an hour.

Muscular Fitness (Continued)

• Muscular flexibility improvements follow the FIT principle as well.

• Static stretching and PNF stretching are preferred techniques.Static technique is most commonly used.PNF is more time consuming and required

assistance from a person trained in the technique.

• For health fitness purposes, flexibility exercises often target the lower back and posterior hip/hamstring muscles ( rationale is to addresses risk of low back pain).

Muscular Fitness (Continued)

• Exercise prescription recommendations for muscular flexibility:Exercises – sufficient number to address

major muscle/tendon groups (significant focus on low back/hip/hamstring area).

Intensity – Position of mild discomfort.Duration – 10 to 30 s (static stretching).Repetitions – 3 to 4 per stretch.Frequency – 2 to 3 d/wk.

Maintenance of Training Effect

• Training adaptations are maintained if intensity is maintained, even if frequency and duration are reduced.

• This applies to both muscular adaptations and aerobic adaptations.

• Training improvements begin to decline relatively quickly with complete inactivity (as soon as two weeks). Principle of reversibility.

Special Populations

1. Cardiopulmonary Patients (Chapters 8 and 9)

Primary goal is to regain functional capacity (i.e. return to work status, ability to perform tasks of daily living).

Primary consideration is to establish exercise intensity below threshold for onset of problems.

Cardiac patients:o Box 8-3, page 179 o Box 8-4, page 180o Box 8-6, page 190

Pulmonary Patients:o page 227 - 229

Special Populations (Continued)

6. Hypertensives (Chapter 9) General goal is to provide well-rounded fitness program

that minimizes risks associated with hypertension. Follow general recommendations for aerobic FIT, with slight

reduction in intensity (40% - 70% VO2R). Emphasis on aerobic activity. Monitor blood pressure before, during, and after exercise. 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. Stage 3 hypertensives should begin pharmacological treatment

prior to starting exercise program (controlled BP prior to starting).

Special Populations (Continued)

7. Diabetics (Chapter 9) Goal is to follow general fitness guidelines

and maintain blood glucose homeostasis. Monitor blood glucose before, during, and after

exercise if taking insulin or oral medication. Avoid exercise at peak insulin times. Do not exercise if blood glucose is > 300 mg/dl

or >240 mg/dl with urinary ketone bodies. Take CHO if blood glucose is < 80 mg/dl.

Note: Table 10-1 (pages 210 – 211) of 6th ed. provides summary of exercise recommendations and precautions.

Special Populations (Continued)

5. The Obese (Chapter 9) Primary goal is likely fat reduction while trying to

maintain lean body mass. Obese individuals will likely lose lean body mass

along with fat mass, but the goal is to minimize this. Focus will be on aerobic activity. Generally recommended to reduce/expend 500 –1,000

kcal/day to loose body fat. Acceptable loss is 1% of body weight/week (1.0 – 2.0 lbs/week for avg. person).

o Exercise objective is to expend >300 kcal/day.o Should not reduce total kcal/day intake below 1,200 kcal.

1996 U.S. Surgeons’ General Report: 1996 U.S. Surgeons’ General Report: Physical Activity and Physical Activity and Health (USDHHS / CDC / ACSM)Health (USDHHS / CDC / ACSM)

AccumulatingAccumulating at least at least 30 minutes30 minutes of of any any kindkind of of moderate intensity physical moderate intensity physical activityactivity on on most daysmost days of the week of the week

would effectively reduce the risk of would effectively reduce the risk of coronary heart disease, type 2 diabetes, coronary heart disease, type 2 diabetes, hypertension, stroke and some kinds of hypertension, stroke and some kinds of cancercancer

Current Recommendation of Current Recommendation of PA for Health PromotionPA for Health Promotion

The End