A Christian Guide to Body Stewardship, Diet and Exercise

Chapter 6: Training for Strength 129 Fortunately, participation in regular strength training can help prevent both fat gain and muscle loss. Figure 6.2 depicts changes in body composition after one year of strength training. The green line represents changes in fat mass, whereas, the orange line represents changes in fat-free mass. As you can see from the figure, this individual lost over 5 lbs. of fat and gained 3.5 lbs. of muscle. Figure 6.2. Impact of Strength Training on Body Composition In addition to improving body composition, regular strength training can also help to improve bone density (amount of bone mineral in bone tissue) and reduce the risk of osteoporosis (disease in which the density and quality of bone are reduced). Research shows that bone density peaks around the age of 25 for most individuals and then begins to deteriorate (Walters & Byl, 2013). These findings depict the importance of regular participation in strength training early (e.g., late teens to mid-20s) in order to establish sufficient bone density and help prevent or delay the onset of osteoporosis. Figure 6.3 depicts bone density scans, as taken by dual-energy x-ray absorptiometry (DEXA), of two active duty servicemembers. The graph on the left depicts a 40-year old female who regularly performed endurance training (e.g., running, rowing), but rarely performed strength training. The graph on the right depicts a 43-year old male who has performed strength training for over 20 years. As depicted in the below graphs, the female servicemember is currently at the 10th percentile for bone density for her age. Conversely, the male servicemember is well above the 90th percentile for bone density for his age. Higher percentiles represent higher levels of bone density and a reduced risk of osteoporosis and fracture.