Exercise Prescription

Aerobic Fitness

Principles of Training

• Overload – Harder work than the body is accustomed to.Training Variables (FIT Principle)

Frequency - number of times per week

Intensity - level of the effort at any given time; speed, weight, hills, water resistance, etc.

Time - duration, reps/sets in weight trainingFrequency and duration together are often referred to as

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

Principles of Training

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

Principles of Training• Progression

Gradually increase the overload in an exercise program over time.

Prevents possible injury and frustration.NOTE: Increase training volume first, then

intensity.

Principles of Training

• Progression – Sedentary but low riskTable 7-1, Page 149– Initial Stage – 4 wks.– Improvement Stage - ~ 20 wks.– Maintenance Stage – lifelong !

Principles of Training• 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 to .85] + RHR

Aerobic Fitness

Target Heart Rate, METs, and RPE

2. Target VO2

VO2 Reserve =

[(VO2 max – VO2 rest) x % intensity] + VO2 rest

Aerobic Fitness

Target Heart Rate, METs, and RPE

3. 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 = [(VO2max – VO2rest) x % intensity] + VO2rest

Note: current ACSM recommendations suggest using % of VO2R instead of % of VO2max

Aerobic Fitness

Target Heart Rate, METs, and RPE

4. RPE – Rating of Perceived Exertion Category Scale (6-20) – Borg Scale Category-Ratio Scale (0-10);

Table 4-7, Page 77.

Aerobic Fitness

Target Heart Rate, METs, and RPE• 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

Target Heart Rate, METs, and RPE

• 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

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

Exercise Duration and Frequency

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

may be necessary to achieve weight loss goals.

Aerobic Fitness

Metabolic Calculations• Metabolic calculations are used to:

Determine predicted maximal exercise aerobic capacity (VO2max)

Determine exercise intensities based on test data (THRR, %VO2R/METs, RPE)

Establish treadmill, cycle, and stepper settings to achieve target exercise intensities.

• Appendix D!!

Aerobic Fitness

Metabolic Calculations• Key Terms:

Gross VO2 represents both the resting and exercise VO2 components.

Net VO2 represents only the exercise VO2 component.

Absolute VO2 represents the oxygen consumption for the total person (l/min).

Relative VO2 represents the oxygen consumption per unit of body weight (ml/kg/min).

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) 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: Pulmonary Patients:

Special Populations

2. 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 lose 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.

Special Populations

3. 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 9-2 (page 209) provides summary of extreme glycemic signs and symptoms.

Special Populations

4. 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 Populations5. Pregnant Women (Chapter 9) Exercise is generally O.K. for pregnant women with no

complications. Intensity should be moderate (high intensity not

recommended). Factors to consider:

Avoid high-impact activities – vertical or horizontal! Be cautious with activities requiring balance as center of gravity

changes during pregnancy. Avoid large increases in body temperature. Proper hydration and increased caloric intake for exercise and

fetal needs are important.

Special Populations

6. Children (Chapter 10) Primary goal is to have participate in regular physical

activity (not necessarily exercise). Attention should be paid to avoid injuries due to

improper exercise/activity. Overuse injuries, often the most common form of injuries in

children.o Be cautious of too much activity (volume) and high intensity.

Be cautious of exercise in heat and cold environments. Children do not respond to extremes as well as adults.

Special Populations

7. Elderly (Chapter 10) Generally follow the same prescription guidelines for the

regular adult population. Consider mode – orthopedic and balance friendly Consider accessibility Consider group setting for adherence Duration vs. intensity – frequent shorter bouts

Questions?

End Prescription

Aerobic Fitness