Relationship among running mileage, bone density, and serum testosterone in male runners

Abstract

Our purpose was to investigate the relationship between running volume and bone mineral mass in adult male runners. Whole body and regional bone mineral density were determined by dual-photon absorptiometry in 22 sedentary controls and 53 runners who were selected according to their running mileage to fall into a 5- to 10-, 15- to 20-, 25- to 30-, 40- to 55-, or 60- to 75-mile/wk group. All groups were of similar age (20-45 yr) and nutritional status, as determined by 7-day food records. Regional sites for bone density measurements included the trunk, spine, pelvis, thighs, and lower legs. In addition, serum total testosterone was determined in each subject and computed tomography scans were made of the lower legs in 34 subjects to assess bone cross-sectional area. No significant differences were detected for bone density measurements with the exception of the lower legs where it was significantly (P less than 0.05) greater for the 15- to 20-mile/wk group than for the control and 5- to 10-mile/wk groups. With mileage greater than 20 miles/wk, bone density of the lower legs showed no further increase and, in fact, tended to decrease, so that for the 60- to 75-mile/wk group it was similar to that of the controls. Cross-sectional area of the tibia and fibula when normalized to body weight tended to be greater as weekly mileage increased and was significantly greater in the 40- to 55-mile/wk runners than in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Bone mineral density in triathletes over a competitive season

“…There are reports of compromised skeletal health in long-distance endurance male athletes (Bilanin et al, 1989;MacDougall et al, 1992;Hetland et al, 1993). For example, in a study of 120 male runners and non-runners, Hetland et al (1993) reported a negative correlation between the distance run weekly and the bone mineral density of longdistance runners.…”

Jogging and bone mineral density in men: results from NHANES III

“…For example, one study reported that men who ran more than 64 km per week had significantly lower vertebral BMD than nonrunners, 23 and another concluded that male long-distance runners had reduced BMD and increased bone turnover compared with controls. 16 MacDougall et al 14 found no further increase in lower-leg BMD in male runners who ran more than 20 miles per week compared with those who ran less; in fact, increased distance was potentially detrimental (i.e., mean BMD in those who ran 60-75 miles per week was similar to that in controls). Our results showing similar femoral BMD in those who jogged frequently (i.e., >20 times/month) and those who jogged less frequently, while exploratory in nature, were consistent with these studies.…”

“…Our results showing similar femoral BMD in those who jogged frequently (i.e., >20 times/month) and those who jogged less frequently, while exploratory in nature, were consistent with these studies. The mechanism underlying this ceiling effect is probably multifactorial and may include factors such as body weight 14 or sex hormone status. 24 Our study focused on the proximal femur, which is a skeletal site that receives increased loading from jogging.…”

“…Some studies have found higher BMD among joggers in the femoral neck, lumbar spine, or total body, 1,[10][11][12] while others have found an association only at lower limb sites. 13,14 Other studies have found that BMD among runners is the same as or lower than in nonrunners. 15,16 A problem of the studies of both men and women has been the use of self-selected athletes, which, coupled with small sample sizes, likely limits generalizability.…”

Experimental validation of finite element predicted bone strain in the human metatarsal

“…This leads to a reduction in BMD (46) which increases the risk of stress fractures, as discussed previously. Studies examining the effect of reduced testosterone levels in male athletes have not observed a reduced BMD (47,48).…”