Most people know that exercise helps make bones stronger. It’s also well known that in the teen years, we lay down most of the bone mass we’ll depend on throughout adulthood. Can the form of exercise or sport chosen by teenagers make any difference in the process of building stronger bones?
Two main forms of activity that can affect bone building are impact loading and active loading. Impact loading includes activities that put a force on the skeleton through contact with a hard surface (e.g. running, gymnastics). Active loading includes activities such as swimming, in which the muscles are active but minimal forces act on the skeleton. Past studies have shown that impact loading has a greater affect than active loading on bone health.
This study was designed to view how these two different forms of activity affected bone mass and development of boys around puberty (ages 12 to 18). Forty-five boys were selected, 18 of whom were involved in impact sports (basketball, tennis) and 27 who were involved in active sports (swimming, water polo). These two groups were also compared to a control group of 12- to 18-year-old boys who were not involved in any kind of organized sports.
Bone density was higher in the impact sports group when compared to both other groups. Participants in both athletic groups had higher bone mineral content than their nonexercising counterparts. They were taller and heavier yet also leaner, too.
Testosterone levels were higher in the impact group compared to the active group, though this did not appear to have any affect on bone density, growth, and development (including sexual development). Impact sports improve bone density more than active sports. But any form of physical activity during the teen years is better than no activity for bone development and body composition.