A comprehensive fitness program tailored to an individual typically focuses on one or more specific skills,
[7] and on age-
[8] or health-related needs such as bone health.
[9] Many sources
[10] also cite mental, social and emotional health as an important part of overall fitness. This is often presented in textbooks as a trianglemade up of three points, which represent physical, emotional, and mental fitness. Physical fitness can also prevent or treat many chronic health conditions brought on by unhealthy lifestyle or aging.
[11] Working out can also help some people sleep better and possibly alleviate some mood disorders in certain individuals.
[12]
Developing research has demonstrated that many of the benefits of exercise are mediated through the role of skeletal muscle as an endocrine organ. That is, contracting muscles release multiple substances known as myokines, which promote the growth of new tissue, tissue repair, and various anti-inflammatory functions, which in turn reduce the risk of developing various inflammatory diseases.
[13]