As with many things, moderation is the key to healthy bones, joints and muscles. High load mechanical forces resulting from overtraining or repetitive overuse can lead to bone microfractures, muscle and tendon fiber tears and a localized connective tissue swelling/spasm cycle induced by ischemia.

This phenomenon is not limited to elite athletes training for competition. A typical adult who participates irregularly in exercise may have a lower threshold for mechanical overload. In addition, various repetitive strain injuries have been identified in occupations that use selected joints. For example, the huge increase in the use of computers has lead to an increase in the prevalence of conditions such as carpal tunnel syndrome.