If you become injured, rest for a while and then find you are unable to return to your favorite sport or exercise without aggravating your injury, you will become frustrated. The injury-rest-re-injury cycle is common for athletic injuries, but you can avoid this cycle using the principles of reconditioning and working back safely to your former level of exercise or sport performance.
Reconditioning after injury means you should modify your normal workouts to control your intensity, judged by overall perception of effort (muscle tension or soreness, joint stress, breathing and chest sensations). Then, you should monitor residual pain in your injured area to an acceptable level.
When you are injury-free, normal conditioning requires you choose a level of exercise that causes enough overload to produce improvement in performance after recovery. If the intensity is too high you may become injured. There is a range of exercise intensity that will work properly to provide conditioning. We call this range the "intensity window." When you are not injured this window is wide. When you are injured this window is very narrow. Too high an intensity will prevent recovery and cause re-injury. During reconditioning you must be very specific in your choice of intensity in order to succeed in helping recovery.
It is helpful to think of pain in two ways. Type I pain is the pain felt during exercise. Type II pain is the residual pain, felt about 1.5 hours after exercise. These should be monitored to help select the right exercise window.
When you are not injured you can use overall Type I pain to regulate exercise intensity; you exercise to the point of slight discomfort or overall pain then go a little further, but short of producing specific pain in a localized area such as a muscle or joint. You have to continue to challenge your general exercise pain in order to achieve maximal performance gains.
Successful uninjured athletes continue to confront pain and push through Type I pain (when it comes to optimizing athletic performance, in the overall sense no pain no gain is true). Type I pain is relieved by rest soon after exercise and does not produce lasting effects.
When you are injured, no pain no gain doesn't work, and you will be frustrated if you try to use a similar approach during reconditioning. Instead of growing stronger you will become re-injured. Type II pain can become intense, even though you felt only slight pain during exercise.
When you are injured you should change your approach. Now you should focus on the injured area and use Type II pain instead of Type I to regulate your reconditioning. When you have no Type II pain or only mild pain relieved in one hour of light activity, you can slightly increase your exercise level. If Type II pain is intense, you should rest for up to three days, and then resume your reconditioning at a lower intensity.
To select appropriate exercise windows you should begin reconditioning with exercise involving static, pain-free stretching. When flexibility has returned you can begin weight lifting (or using resistance machines), using light weights at first and progressing slowly to heavier loads to increase muscle strength. When normal strength has returned you can practice the drills and moves associated with your sport, cautiously at first and gradually increasing intensity.
During each stage of your reconditioning you should take care to choose an intensity that does not increase Type I or Type II pain. As your recovery continues, your exercise window will grow wider and you will find at some point you can increase Type I pain with minimal or no Type II pain.
When you are injured you should recognize that your exercise window has narrowed, and you should take care to concentrate on monitoring your Type II pain. If you follow these guidelines you should be able to recondition an injury without stumbling into the injury-rest-re-injury pathway.