Sex, race, nutritional status, exercise, and overall health all affect peak mass. Bone mass is about 30 percent higher in men than in women. The bone mass is approximately 10 percent higher in blacks than in whites. Following the attainment of peak bone mass, the mass subsequently declines throughout life. Immediately following menopause the bone mass decreases rapidly for 3 to 7 years.
Bone is a dynamic substance.
It is not static as many lay persons think. It changes continuously. Use, disuse, and overuse each affect bone density and mineralization. Osteoclasts are cells that bone. After a fracture or other bone injury they are the cells that are active first.