As a fitness pro, you can’t fix the genetic and environmental contributors to bone loss, but you can encourage physical activity and proper nutrition, both of which improve bone health. More than 70% of Americans don’t get the recommended amount of physical activity (Laskowski 2012), and 50% are considered deficient in vitamin D (Karaguzel & Holick 2010). One systematic review rated calcium, vitamin D, dairy and physical activity/exercise as the most important modifiable lifestyle factors that can influence the development of peak bone mass (NOF 2016).
According to the Surgeon General, physical activity
“is one of the most important controllable lifestyle changes to help prevent (or reduce the risk of) a number of chronic diseases” (OSG 2004), and although it is a leading health indicator, more than 80% of adults do not meet the guidelines for both aerobic and muscle-strengthening activities (ODPHP 2018).
McMillan et al. (2017) state that physical inactivity, or sedentary behavior, has been described as “the major public health problem of our time.” Physical activity is known to influence both bone and muscle metabolism
; therefore, inactivity—or a decline in activity—can affect bone through those two pathways (Tagliaferri et al. 2015). Osteogenesis occurs in response to mechanical loading. Inactivity, with its lack of loading, prevents bones from receiving the signal to adapt, which causes bone loss. It’s a basic use-it-or-lose-it scenario.
While all exercises affect muscle and bone, recent research indicates that some activities help bones more than others. In program development, it is important to consider that the skeletal sites closest to the engaged muscle will have the biggest BMD increases (McMillan et al. 2017). For example, in sprinters and shot putters, BMD is highest in the legs and dominant arm, respectively. This is helpful to know when working with clients who have compromised BMD in certain sites.