Peak bone mass is the largest amount of bone tissue that a person has at any point in life. This occurs within a mature skeleton as bone mass develops all through childhood, adolescence, the teenage years, and even during the years of early adulthood. Most people reach their peak bone mass by the age of 30. Because bones are some of the most rigid, sturdy objects in our bodies, many people forget that they are living tissues, much like muscle. As with muscle mass, bone mass can be lost due to a number of factors.

Just as the body consistently breaks down old muscle tissue and creates new muscle tissue, the body also consistently breaks down bone tissue and replaces it with new bone tissue. As many people have a few periods of peak fitness in their lives during, which they have the most muscle mass of their lives, everyone also has a period in which they have more bone mass than they have ever had before or will ever have again. At this point they have what is considered to be peak bone mass.

After this point, bone mass can be lost. In order to avoid brittle bones, too much loss of bone tissue, or even osteoporosis, people have to work not to allow their bone mass to fall too far below their peak bone mass. This can be done by getting plenty of calcium and also making sure to participate in regular physical activities. Unlike muscle mass, which can clearly be seen under the skin, bone mass is impossible to see without medical technology. This is because bone mass does not just have to do with the size of the bones, but also with the density of the bones.

At the point of peak bone mass, the bones are more dense than ever have been or ever will be in the future. Although the bones may have finished growing in size many year before the point of peak bone mass, they have never stopped developing internally. The difference between a bone at peak bone mass and a bone that has experienced bone density loss or osteoporosis is clear. At peak bone mass the bones are quite solid. However, when bone density has depleted or if osteoporosis sets in, the bones look much more porous and, in a magnified form, can even resemble a pumice stone.