Q: The Fitness First staff has commented that strength training improves bone mass/density.  Please explain.

A: To start, the primary purpose of bones is to provide a structural frame for the body, to work with muscle, ligaments, tendons, and joints to provide movement, to protect vital organs, and to produce blood cells and calcium for the entire body.

Bones are a dynamic tissue that are continuously being broken down and restructured in a process called remodeling.  During remodeling, bones cells called osteoclasts break down and absorb existing bone and other bone cells called osteoblasts deposit new bone.  Peak bone mass is generally reached between the ages of 25 and 30.  Bone mass starts to diminish around the age of 40.

Due to the critical nature of bone, maximizing peak bone mass, maintaining bone mass, and minimizing bone loss during aging are important.  One of the best ways to achieve these goals is through strength training.  Strength training increases the physical stresses on bone. These stresses activate the osteoblasts to deposit new bone in the stressed area.

Similar to muscle, bones respond to progressive overloads.  Progressive overloading means safely and systematically applying higher levels of stress to the bone.  Properly applying the overload leads to greater increases in bone mass or minimizes bone loss due to aging.


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