Guidelines for aerobic exercise
1. It is recommended that exercise routines involving repeated foot impacts be limited to 30 minutes in duration at intensities not exceeding 75% of maximal heart rate. There should be a day of rest between such sessions.
2. A resilient floor should be selected for exercise that involves repeated foot impacts. If such a surface is not available, the exercise routines should be modified to ensure that the feet remain close to the floor throughout the program.
3. Aerobic exercise should be preceded by a gentle warm-up routine that uses the full range of motion of the joints. This increases the elasticity of the muscles and will help prevent potentially injurious movements.
4. Muscles that are used repeatedly during aerobic exercise must be stretched carefully before and afterward.
5. To reduce the severity of impact shock on the lower extremities, repetitive jumping on the same foot should not exceed four consecutive jumps.
6. Extremes of joint flexion and extension (such as deep knee bends and ballistic hyperextension of the knee) should be avoided.
7. The feet should be moved repeatedly to prevent cramping in the intrinsic muscles of the foot.
8. Trunk rotation should be avoided while on the feet with hips or lower spine flexed. Rotational activity in this position subjects the intervertebral disks to very high mechanical stress.
9. Intense physical activity should always be followed by a cool-down period of at least 10 minutes of lighter activity to prevent pooling of blood in the extremities. Hot showers and baths should be avoided immediately after intense physical activity.
10. Participants should be given a specific means of assessing physical status and progress. Working heart rate should be measured during peak levels of exercise to ensure that the intensity of activity is within the desired range. Regular measurement of the recovery heart rate will motivate participants by documenting their progress. Failure to progress as measured by this method may indicate the need for more intense activity during the aerobic phase or may signal the presence of other problems.
Guidelines for Strengthening Exercises
1. Strengthening exercises should not be performed on the same muscles on consecutive days.
2. A general warm-up routine should be performed before muscles are made to work against resistance.
3. Exercises should be preceded and followed by stretching exercises that are specific for the muscles that are made to work against resistance.
4. All strengthening exercises should be performed in a slow and controlled manner. Ballistic (rapid or jerky) movements increase the risk of injury.
5. The most efficient way to improve strength is to allow brief rest periods between bouts of vigorous exercise. Repetitions should be limited to short sets (10 or fewer) that are repeated later.
6. When the strength of one muscle or muscle group is disproportionate to that of the antagonist(s) for that muscle or group, the weaker muscle should be strengthened to restore balance around the joint.
7. Participants should not hold their breath during strength-training exercises. Exhalation should take place during the exertion phase of each repetition.
Guidelines for stretching exercises
1. Stretching exercises may be performed as often as desired, preferably at least once a day.
2. A general warm-up routine should be performed before muscles are stretched.
3. Stretching routines should be performed statically, without holding the breath. Rapid, jerky movements should be avoided.
4. Each stretch should be held long enough so that relaxation will occur sufficiently to achieve the maximum benefit of the stretch. This can vary from as little as 6 seconds in some individuals to 20 seconds in others.
5. Muscles should be stretched only to the point of tension. Pain should be regarded as a signal that a stretch has gone too far.
