Bone Mineral Content and Density Among Female NCAA Division I Athletes Across the Competitive Season and Over a Multi-Year Time Frame

Abstract

Stanforth, D, Lu, T, Stults-Kolehmainen, MA, Crim, BN, and Stanforth, PR. Bone mineral content and density among female NCAA Division I athletes across the competitive season and over a multi-year time frame. J Strength Cond Res 30(10): 2828-2838, 2016-Longitudinal and cross-sectional bone mineral content (BMC) and bone mineral density (BMD) comparisons were made among impact and nonimpact sports. Female collegiate athletes, 18-23 years of age, from basketball (BB; n = 38), soccer (SOC; n = 47), swimming (SW; n = 52), track sprinters and jumpers (TR; n = 49), and volleyball (VB; n = 26) had BMC/BMD measures preseason and postseason over 3 years. Control groups of 85 college females, 18-24 years of age, who completed 2 tests 1-3 years apart and of 170 college females, 18-20 years of age, were used for the longitudinal and cross-sectional analyses, respectively. A restricted maximum likelihood linear mixed model regression analysis with a compound symmetric heterogeneous variance-covariance matrix structure was used for all analyses (p ≤ 0.05). Increases from year-1 preseason to year-3 postseason included the following: total BMC (3.3%), total BMD (1.4%), and spine BMD (4.5%) for BB; total BMC (1.5%) and leg BMD (1.2%) for SOC; arm (1.8%), leg (1.9%), and total BMD (5.7%) for SW; total BMC (2.0%), arm (1.7%), leg (2.3%), pelvis (3.4%), spine (6.0%), and total BMD (2.3%) for TR; and arm (4.1%), leg (2.0%), pelvis (2.0%), spine (2.0%), and total BMD (2.7%) for VB. Comparisons among sports determined that BB had higher BMC and BMD values than all other sports for all variables except spine and total BMD; BB, SOC, TR, and VB had higher total BMC (11-29%), leg BMD (13-20%), and total BMD (9-15%) than SW and CON, and there were few differences among SOC, TR, and VB. In conclusion, small, significant increases in many BMC and BMD measures occur during female athlete's collegiate careers. The BMC and BMD differences between impact and nonimpact sports are large compared with smaller differences within impact sports.

Maintenance of Serum Ionized Calcium During Exercise Attenuates Parathyroid Hormone and Bone Resorption Responses

“…Bone mineral density (BMD) is known to vary among athletes who participate in different sports. In general, BMD tends to be lower in those who participate in weight‐supported (eg, cycling) or low‐impact activities (eg, cross‐country skiing) than in athletes who participate in higher‐impact activities (eg, volleyball) . This suggests that forces acting on bone in low‐impact and non‐impact sports are not sufficient to generate the anabolic skeletal response that occurs with high‐impact activities.…”

“…In general, BMD tends to be lower in those who participate in weight-supported (eg, cycling) or low-impact activities (eg, cross-country skiing) than in athletes who participate in higher-impact activities (eg, volleyball). (1)(2)(3) This suggests that forces acting on bone in low-impact and non-impact sports are not sufficient to generate the anabolic skeletal response that occurs with high-impact activities. However, bone loss has been observed over time in some athletes, at an age when stable BMD would be expected, suggesting that exercise may sometimes have catabolic skeletal effects.…”

Vitamin D Status and Bone Mineral Density in Female Collegiate Dancers and Cheerleaders

“…Physical activity is known to be a factor in promoting bone formation and moderate levels of physical activity, as little as twice per week, have been shown to reduce the risk of fractures [2]. Athletes, regardless of sport, have higher bone mineral density than non-athletes [3,[6][7][8], and BMD is higher in athletes engaged in high impact sports such as basketball and volleyball than in athletes in low-impact or non-impact sports such as swimming, water polo, and distance running [5][6][7][9][10][11][12]. Although sports with high-impact loading are associated with higher bone mineral density than low-impact or non-impact sports, confounding variables are differences in the athletes' body size and sport-specific training [11,13].…”

“…Further support for this comes from the finding that BMD did not differ between dancers and cheerleaders at any of the sites measured. Previous studies have shown a sport specific response to loading patterns in bone mineral density [6,9,11,29]. Team female team handball players had higher forearm BMD, considered to be a weight-bearing site in this sport, than female soccer players [29].…”

“…However, it has yet to be determined if any one sport or type of athletic activity is more beneficial or osteogenic than another. In general, research has shown that sports that have a repeated occurrence of high impact movements, such as gymnastics, volleyball, basketball, and track & field jumping events, have a greater effect on BMD when compared with sports with little or no impact such as cycling, water polo, and swimming [5][6][7][9][10][11][12].…”