Bone Loss… What Can Exercise Do?
It is easy to think of our bones as a hard and unchanging aspect of overall health, but bone is actually extremely dynamic. We typically will accrue large amounts of bone mineral density as children and young adults. As we age, bone loss will begin to outpace bone gain, leading to increased risk for osteopenia and osteoporosis. These conditions will put us at greater risk for fracture later in life. The impact of osteoporosis is far-reaching; nearly 1 in 2 women and 1 in 4 men will break a bone because of osteoporosis, accounting for nearly $17-20 billion in healthcare costs and work lost per year (1).
There are several ways we can promote bone health while attenuating the increased risk for fracture due to osteopenia and osteoporosis. Such ways include changes in diet and pharmacologic therapies. Exercise is another great way to help attenuate this risk and may actually help accrue small gains in bone mineral density in several ways:
Several studies have documented a positive relationship between muscular strength and bone mineral density regardless of age or sex (2, 3, 4). This means that stronger muscles are associated with stronger bones. When muscles contract, they pull on bones and stimulate bone growth.
JUMP! To improve the health of a bone- you must challenge it! Jumping challenges the bone in a unique way, forcing it to respond to this challenge by laying down new bone. In fact, women who engaged in regular resistance training combined with 50-100 jumps 3x/week increased or maintained hip bone mass (7). Jumping routines are not currently recommended for those with already diagnosed osteoporosis.
When an astronaut goes to space, he or she may lose one at a rate of up to 1% every month (that is nearly 12-24 times faster than the rate we see as we age)! This is primarily due to the significant influence of gravity- the body will adapt to this reduced load. Therefore, it is important to perform exercise in which the body is being fully “loaded”. Non-weight bearing exercises such as cycling are not typically recommended with the goal of improving bone health (6).
Before beginning any exercise program, consult with a trained professional to determine its safety and efficacy. If you have been diagnosed with osteoporosis, activities that put higher stresses on the bone, such as jumping or trunk flexion exercises (i.e. toe touches, rowing) should be avoided. In order to promote bone health, prevent falls, and improve balance, begin with a well-rounded program consisting of resistance training and brisk walking (if hills are tolerated without pain, incorporate a few into your route). Exercise can be “medicine”… even for your bones!
- Bushman, Barbara, and American College of Sports Medicine. ACSM’s Complete Guide to Fitness & Health, 2E. Human Kinetics, 2017.