Wolff’s law is a theory developed by the German Anatomist/Surgeon Julius Wolff (1836-1902) in the 19th century that states that bone in a healthy person or animal will adapt to the loads it is placed under.
If loading on a particular bone increases, the bone will remodel itself over time to become stronger to resist that sort of loading. The external cortical portion of the bone becomes thicker as a result.
The converse is true as well: if the loading on a bone decreases, the bone will become weaker due to turnover as it is less metabolically costly to maintain and there is no stimulus for continued remodeling that is required to maintain bone mass.
In some extreme cases the fibula (a thin non-weight bearing bone) has been transplanted to replace a shattered tibia. Do you know what the result is? The transplanted fibula gradually takes on the shape of a tibia due to Woolf’s Law of Bone.
We must remember that everything in the body responds to stress, muscles, tendons, cartilage and bone. In fact studies have shown that athletes have thicker hyaline cartilage (lining bones) than non-athletes. This improves the body’s protective mechanism in delaying osteoarthritis.
Weightlifters often display increases in bone density in response to their training.