EXERCISE PRESCRIPTION :: how to prescribe an exercise in a scientific way???

Human body is built and designed for movements.Patterns of today's living have channeled the average human an increasingly sedentary existence. Physiologically we have not adapted well to this inactive lifestyle. Hence prescribing exercise is one of the biggest challenge for physiotherapists during the rehabilitation process. Most of the practitioners are unaware of the importance of exercise prescriptions in reducing exercise related complications. understanding about basics of exercise prescription is important in safe and effective physiotherapy practices.

EXERCISE PRESCRIPTIONS

The exercise prescription involves four basic factors:

Mode of exercise
frequency of participation
Duration of each exercise bout
Intensity of a Exercise Bout

Before examining the components of the exercise prescription, We must consider how much exercise is effective. A minimum threshold for frequency, duration, and intensity of exercise must be reached before any aerobic defects are obtained. A minimal threshold for frequency ,duration and intensity must be reached to gain aerobic benefits from that exercise. Further more , minimal threshold vary widely , making individualized exercise prescription necessary.

Exercise Mode

The prescribed exercise program should focus on one or more modes orb types of cardiovascular endurance activities.The activities most prescribed are.

Walking
Jogging
Running
Hiking

Spinning, aerobic dance , box or bench stepping and most racket sports also have been shown to improve aerobic capacity.

Exercise Frequency

The frequency of exercise prescription although certainly an important factor to consider, is probably less critical than either exercise duration or intensity. Research studies conducted on exercise frequency shown that 3 to 5 days per week is an optimal frequency.That does not mean that 6 or 7 days per week wont give additional results.

Exercise initially should be limited to 3 or 4 days per week and increased up to 5 or more days per week only if the activity is enjoyed and physically tolerated.

Exercise Duration

Several Studies have demonstrated improvement of cardiovascular conditioning with endurance exercise period as brief as 20- 30 minutes will give optimal results. Exercise duration cannot be discussed appropriately without also discussing exercise intensity.Similar improvements in aerobic capacities are gained with either a short duration high intensity exercise or a long duration low intensity exercise program.

Exercise Intensity

exercise intensity can be stated according to the level of exercise, such as

minimal intensity
moderate intensity
sub maximal intensity
high intensity

The intensity of exercise appear to be most important factor in exercise prescription. It can be stated in the basis of

VO2 max
RPE ( Rate of Perceived Exertion)
MET
Max Heart rate

The last one is more common among others.

ie . minimum intensity Below 40% of MHR

Moderate Intensity Between-60% MHR

Sub-maximal Intensity Between 60- 85% MHR

High Intensity Above 90% MHR

Monitoring Exercise Intensity

Resting Heart Rate ( RHR) - should be measured prior to the training
Maximum Heart rate (MHR) - which means the maximum level of heart rate that can be achieved during any exercise without causing any undesirable effect on the individual , usually calculated subtracting the individuals age from 220 .ie. Max HR = 220- age)
Target Heart rate - which means how much heart rate could be achieved during a particular exercise intensity range

THR = RHR + 0.75 (MHR -RHR) { Karvonen method

Metabolic Equivalent

exercise intensity also can be prescribed using metabolic equivalent system. The amount of oxygen your body consumes is directly proportional to the energy you exp[end during the physical activity. At rest your body uses approximately 3.5 ml of oxygen per kilogram of body weight per minute.this resting metabolic rate is prescribed as 1 MET. All activities are classified according to the rating MET.

EXERCISE PROGRAMS

It must include three steps