Upper-limb bone mineral density of female collegiate gymnasts versus controls

PURPOSE: We examined bilateral bone mineral density (BMD) in the arms of female college gymnasts to assess the relative contribution of high-impact loading forces versus daily activities on bone plasticity. METHODS: Twenty-five female collegiate gymnasts and 25 controls were studied. BMD of the lumbar spine, proximal femur, and whole body were assessed via dual energy x-ray absorptiometry. Upper-limb BMD was determined by custom analyses of the whole-body scans to examine arms individually. RESULTS: BMD of gymnasts was significantly (P < 0.0001) greater than controls at all sites. Whole-body BMD was 8% higher in gymnasts (1.270 +/- 0.078 vs 1.175 +/- 0.073 g x cm(-2)), with 18-19% differences in the lumbar spine (1.427 +/- 0.144 vs 1.212 +/- 0.106 g x cm(-2), right proximal femur (1.298 +/- 0.101 vs 1.100 +/- 0.129 g x cm(-2)), and left proximal femur (1.293 +/- 0.111 vs 1.104 +/- 0.133 g x cm(-2)). Arm BMD was 17% greater in gymnasts, with higher values in both dominant (1.013 + 0.067 vs 0.875 + 0.066 g x cm(-2)) and nondominant (1.002 + 0.060 vs 0.849 + 0.062 g x cm(-2)) arms. Intragroup comparisons revealed a significantly (P < 0.0001) greater BMD in the dominant arm of the controls but no side-to-side difference in the arms of the gymnasts. CONCLUSIONS: Upper-limb BMD followed use patterns in both gymnasts and controls, demonstrating that the forces imposed on the arms with gymnastics training enhanced BMD and resulted in no bilateral differences. These findings illustrate the association between gymnastics training and increased BMD throughout the body, suggesting that the high BMD values observed in gymnasts are due primarily to the activity itself rather than selection bias.     

Spine bone mineral density increases in experienced but not novice collegiate female rowers

PURPOSE: There is evidence that rowing exercise targets the spine, but the dose of exercise required to build bone is poorly understood. To further explore this topic, we studied the bone response at the spine in novice and experienced female collegiate rowers over their 6-month competitive season. We hypothesized that, with rowing strokes similar between groups during training, experienced rowers would produce greater force at the spine than novices and thus, gain more bone mineral density (BMD). METHODS: Subjects included 16 experienced rowers (21.2 +/- 1.2 yr) who had been rowing 26 +/- 10 months and 19 novice rowers (19.5 +/- 0.8 yr) who had been rowing three months and 14 controls (19.2 +/- 1.6 yr). BMD was assessed by DXA at baseline and after the 6-month competitive season. During the season, all rowers participated in the same training program and took approximately the same number of strokes per training session (1000-1200 repetitions). On the 2000- and 6000-m rowing ergometer tests experienced rowers had faster times, indicating that their power output, and thus force production, was greater than novices. RESULTS: In ANCOVA, adjusting for body mass index, age, and initial BMD, the experienced rowers demonstrated a 2.5% increase at the spine that was significantly different than that of the novice rowers, but BMD change scores in the rowing groups were not different than controls. CONCLUSION: Because the number of strokes (repetitions) was similar between rowing groups during training, the higher power output in experienced rowers produced higher forces at the spine over the 6-month period that resulted in gains in spine BMD. These results support the theory that force magnitude is a key variable in osteogenesis.     

Effect of increased training volume on nutrient intake of male collegiate swimmers.

To assess the effect of a period of increasing training on dietary quantity and quality, a men's collegiate swim team (n = 24) was divided into two groups of equal skill at the start of a 25-week season of training and competition. After a 4-week conditioning period, the "Long" group underwent a 6-week period during which they swam up to 44,000 m.wk-1, while the "Short" group maintained their swimming at 22,000 m.wk-1. For the remainder of the season, the two groups swam together, performing the same volume and intensity of training. Two-day food intake records were obtained during the early season, during the period of increased training, and during the late season. Swimmers' diets during the early season averaged 15.3 MJ, with 55% from carbohydrate (500 g), and exceeded RDAs for all nutrients assessed. During the increased training period, energy and carbohydrate intakes of the Long group increased significantly (p less than 0.05) to 17.7 MJ and 600 g respectively, but the percentage of energy derived from carbohydrate, protein and fat was stable. Intakes of the Short group did not change over the season. Energy intake did not fully compensate for expenditure, as both groups maintained weight but lost subcutaneous fat. An increase in training volume appears to result in an increased consumption of the athletes' usual diets.     

Effect of increased training volume on blood lipids and lipoproteins in male collegiate swimmers.

This study was conducted to assess whether a previously described dose-response relationship between the amount of exercise and the magnitude of change in blood lipid and lipoprotein levels is observed with large volumes of exercise in young, healthy individuals. Blood lipid and lipoprotein levels were monitored during a 25-wk season of training and competition in experienced male collegiate swimmers, who were divided into two groups matched for swimming skill. After an initial 4-wk conditioning period for both groups, one group (N = 11) underwent a 6-wk period during which their training volume was increased from 22,000 m.wk-1 to 44,000 m.wk-1. The other group (N = 13) maintained their swimming distance at 22,000 m.wk-1 during this period. During the remaining 15 wk of the season, both groups swam approximately 22,000 m.wk-1. Swimmers' body weights did not change over the season, but body fat decreased significantly (P less than 0.01). No changes in HDL cholesterol were observed during the season in either the increased training or the regular training groups. Total and LDL cholesterol levels were lower at 20 wk than at the start of the study, but final levels did not differ from initial levels. Thus, the volume of swimming exercise may not be related to the degree of change in blood lipid and lipoprotein levels in healthy subjects with high activity levels.     

Plasma glutamine changes after high-intensity exercise in elite male swimmers

The aim of this study was to establish the pattern and time course of plasma glutamine recovery after acute, high-intensity exercise in well-trained swimmers. In Study 1, elite male swimmers (n=8) performed 15 x 100 m swimming intervals (ITS) at 70% and 95% of maximal 100m freestyle time. Resting plasma glutaminle levels were determined on a nonexercise control day (0% ITS). Venous blood samples were obtained prior to, immediately afte;, and 30, 60, 120, and 150 mini postexercise. In Study 2, the 95% ITS was repeated in elite male swuimmers (n=8), while control subjects (n=8) did not exercise, to test for any diurnal variation in plasma glutamine levels. Venous blood samples were obtained prior to and 2, 4, 6, and 8 h postexercise. In Study 1, no change was observed in plasma glutamine following the 0% (control) and 70% ITS, but following the 95% ITS glutamine decreased significantly (p < 0.01) over the recovery period. In Study 2, plasma glutamine again decreased over the recovery period in the swimmers, but no changes were observed in the controls. It was concluded that intensive swim traininlg results in postexercise decreases in plasma glutamine levels. Because glutamine has been suggested as a marker of overtraining, a need to measure glutaminle at standard times within training programs is indicated.     

Regional bone mineral density in male athletes: a comparison of soccer players, runners and controls

Objectives

To investigate the association of soccer playing and long‐distance running with total and regional bone mineral density (BMD).

Design

Cross‐sectional study.

Setting

Academic medical centre.

Participants

Elite male soccer players (n = 15), elite male long‐distance runners (n = 15) and sedentary male controls (n = 15) aged 20–30 years.

Main outcome measurements

BMD (g/cm²) of the lumbar spine (L1–L4), right hip, right leg and total body were assessed by dual‐energy x‐ray absorptiometry, and a scan of the right calcaneus was performed with a peripheral instantaneous x‐ray imaging bone densitometer.

Results

After adjustment for age, weight and percentage body fat, soccer players had significantly higher whole body, spine, right hip, right leg and calcaneal BMD than controls (p = 0.008, p = 0.041, p<0.001, p = 0.019, p<0.001, respectively) and significantly higher right hip and spine BMD than runners (p = 0.012 and p = 0.009, respectively). Runners had higher calcaneal BMD than controls (p = 0.002). Forty percent of the runners had T‐scores of the lumbar spine between −1 and −2.5. Controls were similar: 34% had T‐scores below −1 (including 7% with T‐scores lower than −2.5).

Conclusions

Playing soccer is associated with higher BMD of the skeleton at all sites measured. Running is associated with higher BMD at directly loaded sites (the calcaneus) but not at relatively unloaded sites (the spine). Specific loading conditions, seen in ball sports or in running, play a pivotal role in skeletal adaptation. The importance of including an appropriate control group in clinical studies is underlined.     

Muscle strength correlates with total body bone mineral density in young women but not in men

BACKGROUND: Osteoporosis is a growing health problem. One of the proposed reasons for this is a more sedentary lifestyle. The aim of this study was to investigate the associations between muscle strength and total body bone mineral density (TBMD) in young adults at expected peak bone mass. METHODS: Sixty-four women and 61 men (total 125) 21 years of age were included. Handgrip strength, isokinetic knee-flexion and -extension muscle strength, TBMD, and body composition were measured. RESULTS: Univariate regression analyses showed that knee flexion and extension explained almost 30% of the variation in TBMD in women, whereas handgrip strength was not associated with TBMD. In men, no correlation between any measures of muscle strength and TBMD was evident. Stepwise regression analysis showed that knee-flexion and -extension muscle strength in women were associated with TBMD, R2=0.27. In men, lean body mass, fat mass, weight, and height were predictors for TBMD, R2=0.43, whereas muscle strength did not affect the prediction of TBMD. CONCLUSIONS: Muscle strength at weight-bearing sites is related to TBMD in women, whereas body composition is related to TBMD in men. The association of lower limb strength on TBMD only in young women indicates a gender difference.     

男性糖尿病患者身体成分变化与骨密度相关性分析

目的分析男性2型糖尿病（DM）患者身体成分变化与骨密度（BMD）的关系。方法采用双能x线BMD检测仪,对88例男性2型DM患者（DM组）和97例男性非DM患者（非DM组）进行腰椎（L1-L4）正位、左股骨和全身BMD检测和身体成分检测,并分析比较。结果（1）两组问所测部位BMD均无显著差异,但DM组全身、躯干和左大腿脂肪质量,左大腿肌肉质量均比非DM组显著降低。（2）在DM组,体重与腰椎BMD、左髋各部BMD和全身BMD等呈显著正相关;体重指数与左股骨各部（Wards三角除外）BMD和全身BMD等呈显著正相关;全身脂肪质量与L1、L3和全身BMD等呈显著正相关;左大腿肌肉质量分别与L1、L3、股骨颈、股骨干和全身BMD等呈显著正相关。（3）在非DM组,体重、体重指数和各部组织成分质量均与全身BMD呈显著正相关。体重、体重指数、全身脂肪质量和躯干脂肪质量均分别与腰椎BMD、左股骨各部BMD等呈显著正相关;全身肌肉质量与左股骨各部BMD（Wards三角除外）、L1BMD呈显著正相关;左大腿肌肉质量也与左股骨各部BMD呈明显正相关;躯干肌肉质量与股骨颈BMD呈显著正相关。结论男性DM患者身体成分变化主要表现为脂肪质量和左大腿肌肉质量明显减少,身体成分与BMD存在一定相关性,但与非DM者相比有较多不同,其差异可能与糖尿病引起的代谢异常有关。     

Comparison of bone mineral density in adolescent male soccer and basketball players

Purpose

The aim of this study was to compare bone mineral density (BMD) in adolescent male basketball (BB) and soccer (S) players.

Methods

The study included Estonian national youth league level participants: 12 BB (16.3 ± 0.7 years, 186.8 ± 6.6 cm, 80.9 ± 11.9 kg) and 15 S players (16.0 ± 0.3 years, 178.5 ± 8.1 cm, 66.3 ± 6.8 kg). All participants had a history of 7.9 ± 2.9 years of training, with training loads of 9.2 ± 1.8 h per week. Body composition and BMD were determined by dual X-ray absorptiometry (DXA).

Results

BB were significantly taller, heavier and had greater lean body mass (LBM) compared to S. No significant (P < 0.05) differences existed in age, body fat %, sports participation, and weekly training load. BB had significantly (P < 0.05) greater BMD values in total body, lumbar spine, right arm, left arm, right leg, right femur, right femoral neck, and right femoral shaft compared to S. The biggest between-groups difference (P < 0.001) existed in upper extremities (25–28%). LBM was the main determinant for all BMD variables.

Conclusions

Regular participation in basketball and soccer practice in adolescent males is associated with enhanced BMD in loaded sites specific to demands of the sport. Basketball practice seems to have higher impact on non-weight bearing bones, compared to soccer.

     

The spatial-temporal and coordinative structures in elite male 100-m front crawl swimmers

This study analysed the spatial-temporal and coordinative structures in 12 elite male 100-m front crawl swimmers. Swim performance was analysed over each length of a 25-m pool divided into five zones of 5 m. Velocity (V), stroke rate (SR), and stroke length (SL) were calculated for each zone and each length. Four stroke phases were identified by video analysis and the Index of Coordination (IdC) was established. Three modes of coordination were identified: catch-up (IdC < 0), opposition (IdC = 0), and superposition (IdC > 0). The swimmers tended to reduce the decrease in V and SR over the course of the 100 m by maintaining a stable SL. In fact, these spatial-temporal values were stable during the time spent stroking and were higher or lower during the start, the turns (in and out), and the finish. Thus the spatial-temporal changes did not occur within the lengths, but between them. Conversely, the evolution in the IdC showed that the swimmers had to install the stroke at the beginning and only reached a stable coordination in the second part of the race. Moreover, the IdC increased throughout the different zones of each 25-m length, indicating changes in motor organisation, particularly increases in the push or pull phases. The IdC values corresponded to a superposition of the arms, linked to a six-beat leg kick. Achievement of an effective superposition coordination occurred by boosting the stroke just after the turn-out until the end of the length. Regarding the spatial-temporal and coordinative structures of a 100-m front crawl, great swimming skill was reflected by both high and stable data.     

Measurements of bone mineral density. Mineral density in metabolic bone disease.

Bone metabolism and thus bone remodelling and bone mineral content are profoundly influenced by many hormonal and metabolic factors. This review presents the state of the art procedures for bone mineral absorptiometry and examines the interactions of endocrine and metabolic diseases and bone mineral content. Preventive and therapeutic modalities of osteoporosis are discussed in this context.     

Whole body vibration increases hip bone mineral density in road cyclists

This study aimed to determine the effects of 10 weeks of whole body vibration training on the bone density of well-trained road cyclists. 15 road cyclists were assigned to either a vibrating group (n=8), who undertook 15 min of intermittent whole body vibration at 30 Hz, 3 times per week while continuing with their normal cycling training; or a control group (n=7), who continued with their normal cycling training for the 10-week period. Cyclists were age, body mass and height matched with 15 sedentary participants. At baseline, all participants underwent regional dual x-ray absorptiometry scans, where both cycling groups had lower pelvic (p<0.050) and higher head bone mineral density (p<0.050) than the sedentary participants with no other differences observed. After 10 weeks of training, vibrating cyclists showed a significantly greater increase in hip bone mineral density (0.020±0.010 g.cm - 2 (1.65%), p=0.024) while the control cyclists ( - 0.004±0.001 g.cm - 2 (0%)) showed no change (p>0.050). The control group had a significantly lower spine bone mineral density (1.027±0.140 g.cm - 2, p=0.020) compared to baseline (1.039±0.140 g.cm - 2). This loss was not observed in the vibrating group. 10 weeks of whole body vibration training increased hip and preserved spine bone mineral density in road cyclists.     

Coordination in front crawl in elite triathletes and elite swimmers

The aim of this study was to compare the arm coordination in 19 elite triathletes and 15 elite swimmers at six different velocities between 80 % and 100 % of their maximal velocity (Vmax). The different phases of the stroke (A: entry; B: pull; C: push; D: recovery) were identified by video analysis. An index of coordination (IdC) was calculated. It was the time that separated the beginning of the propulsive phase of one arm from the end of the propulsive phase of the other arm. IdC allows to express the mode of arm coordination: catch-up, IdC < 0; opposition, IdC = 0; superposition, IdC > 0. Between 80 % and 98 % Vmax, elite triathletes showed similar increases in IdC than swimmers (from -8.8 % to 2.6 % vs from -8.6 % to 0.3 %) switching from a catch-up to a superposition coordination. Between 88 % and Vmax, triathletes increased the propulsive phase (B+C) less (p < 0.01) than swimmers (3.4 % vs 8.5 %) and increased the recovery phase (0.8 %) when swimmers reduced it (-1.6 %). Between V5 and Vmax, both triathletes and swimmers had a significant (p < 0.01) difference in IdC change (-1.7 % vs 2.3 %). Moreover, triathletes reduced the propulsive phase when swimmers increased it (-0.6 % vs 3.2 %). The lower velocity of the triathletes was associated to a shorter stroke length when compared to the swimmers (1.70 m vs 2.15 m at Vmax). The stroke rates were not statistically different (55.1 vs 51.2 stroke x min(-1) at Vmax). Thus, monitoring IdC and stroke length is recommended for triathletes mainly at maximal velocity.     

Radiation exposure in bone mineral density assessment.

Osteoporosis is a systematic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue which leads to diminished biomechanical competence of the skeleton and low-trauma or atraumatic fractures. Due to increased awareness of the impact of osteoporosis on the elderly population, the use of bone densitometric techniques is becoming more widespread. Considerable progress has been made in the development of non-invasive methods for the assessment of the skeleton. While DXA and QCT are commonly used techniques, the popularity of other approaches such as RA, SXA and QUS is gaining grounds. QCT has an advantage over the other techniques in its ability to measure the true volumetric density of trabecular or cortical bone. We therefore present an overview of these current techniques for bone mineral density (BMD) measurements. In the second section we discuss the radiation doses incurred in BMD measurements by patients and methods for reducing patient and staff radiation exposure are given. Studies of radiation dose to patient from DXA confirms that patient dose is small (0.08-4.6 muSv) compared to that given by many other investigations involving ionizing radiation. Fan beam technology with increased resolution has resulted in increase patient dose radiation dose (6.7-31 muSv) but this is still relatively small. Carrying vertebral morphometry using DXA also incurs less radiation dose (< 60 muSv) than standard lateral radiographs QCT has radiation dose (25-360 muSv) comparable to simple radiological examination such as chest X-ray but lower than imaging CT. Radiation dose from other techniques such as RA and SXA are in the same order of magnitude as pencil beam DXA. For pencil beam DXA and SXA systems the time average dose to staff from scatter is very low even with the operator sitting as close as 1 m from the patient during measurement. However the scatter dose from fan beam DXA systems is considerable higher and approaches limits set by regulator bodies for occupational exposure.     

Regional bone mineral density after resistive training in young and older men and women

PURPOSE: The purpose of this study was to determine the effects of 6 months of whole-body resistive training (RT) on total and regional bone mineral density (BMD) and bone mineral content (BMC) by age and gender in young and older men and women. METHODS: Younger men (n=10) and women (n=7) aged 20-29 years (25+/-1 years) and older men (n=10) and women (n=10) aged 65-74 years (69+/-1 years) participated in 6 months of progressive whole-body RT. Upper- and lower-body strength was assessed by the one repetition maximum (1RM) test, and total body fat, lean tissue mass, femoral neck BMD, Ward's triangle BMD, greater trochanter BMD, total-body BMD, and L2-L4 spine BMD were determined by dual-energy X-ray absorptiometry before and after 6 months of RT. RESULTS: Percent body fat decreased only in the young men (P<0.05). Lean tissue mass increased after training in young men and women and older men (P<0.05) but did not change significantly in older women. Upper- and lower-body 1RM strength increased in all groups (P<0.01). Overall, there was a significant increase in BMD at the femoral neck, ward's triangle and greater trochanter BMD, as well as total body BMC and leg BMC (P<0.05). Total-body BMD and L2-L4 spine BMD did not change with RT. There were no gender differences in the training response between men and women for any of the BMD regions and no age differences in the training response, except for a trend between young and older subjects for femoral neck (P<0.08). CONCLUSION: A 6-month RT program increases muscle mass and improves BMD of the femoral region in young and healthy older men and women as a group, with a trend for this to be greater in young subjects.     

Regional bone mineral measurements

Total body dual-photon transmission scanning was performed in 9 control persons, 15 athletes and in 5 patients with eating disorders. Total body bone mineral mass was measured, with a reproducibility of 2%; for regional bone mineral mass the reproducibility was 4%. The fraction of total bone mineral in the spines and heads of women is greater than in men. Patients with eating disorders have a smaller fraction of total body mineral in the pelvis than female controls. Weight lifters have a significantly greater mineral mass in the trunk region than other athletes and male controls. These and other differences are consistent with the conclusion that total body dual-photon absorptiometry allows quantitation of the distribution of mineral within the skeleton.     

Quality of life assessment in elite collegiate athletes.

The objectives of this study were to establish baseline Medical Outcomes Study Short Form Health Survey (SF-36) data for Division I collegiate athletes and to determine the effects of injury severity and training time. All participating athletes (N = 562) at a major university were evaluated with the SF-36. Regression analysis was performed to identify predictive factors. When the men without injury were compared with a previously established norm group, there was a significant increase in the role emotional score. In the women without injury there were significant increases in mental component summary, physical function, role emotional, mental health, and vitality scores when compared with the norm group. Serious injury was a predictor of lower scores in all domains, whereas minimal injury was predictive of lower physical component summary, role physical, bodily pain, social function, and general health scores. Increased training time was predictive of higher mental component summary, role physical, vitality, and general health scores. Elite collegiate athletes scored differently from previously established age-matched norms, and injury was a strong predictor of lower scores.     

High femoral bone mineral content and density in male football (soccer) players

PURPOSE: This investigation examined the effect that long-term football (soccer) participation may have on areal bone mineral density (BMD) and bone mineral content (BMC) in male football players. METHODS: Dual energy x-ray absorptiometry (DXA) scans were obtained in 33 recreational male football players active in football for the last 12 yr and 19 nonactive subjects from the same population. Both groups had comparable age (23 +/- 4 yr vs 24 +/- 3 yr), body mass (73 +/- 7 kg vs 72 +/- 11 kg), height (176 +/- 5 cm vs 176 +/- 8 cm), and calcium intake (23 +/- 10 mg.kg(-1).d(-1) vs 20 +/- 11 mg.kg(-1).d(-1) (mean +/- SD). RESULTS: The football players showed 8% greater total lean mass (P < 0.001), 13% greater whole-body BMC (P < 0.001), and 5 units lower percentage body fat (P < 0.001) than control subjects. Lumbar spine (L2-L4) BMC and BMD were 13% and 10% higher, respectively, in the football players than in the control subjects (P < 0.05). Furthermore, football players displayed higher femoral neck BMC (24%, 18%, 23%, and 24% for the femoral neck, intertrochanteric, greater trochanter, and Ward's triangle subregions, respectively, P < 0.05) and BMD (21%, 19%, 21%, and 27%, respectively, P < 0.05) than controls. BMC in the whole leg was 16-17% greater in the football players, mainly because of enhanced BMD (9-10%) but also because of bone hypertrophy, since the area occupied by the osseous pixels was 7% higher (867 +/- 63 cm2 vs 814 +/- 26 cm2, P < 0.05). Leg muscle mass was 11% higher in the football players than in the control subjects (20,635 +/- 2,073 g vs 18,331 +/- 2,301 g, P < 0.001). No differences were found between the legs in either groups for BMC, BMD, and muscle mass. Left leg muscle mass was correlated with femoral neck BMC and BMD (P < 0.001), as well as with lumbar spine (L2-L4) BMC and BMD (P < 0.001). CONCLUSION: Long-term football participation, starting at prepubertal age, is associated with markedly increased BMC and BMD at the femoral neck and lumbar spine regions.     

The relationship of sustained exercise training and bone mineral density in aging male runners

Fifty-six men aged 42–73 years (50.2±10.0 years), who were competitive distance runners 20–25 years previously, were examined for bone mineral density (BMD) to determine the relationship between sustained distance running and BMD. Subjects were classified as being highly trained (HT, n =17), moderately trained (MT, n =29) or untrained (UT, n =10) according to their training in recent years. Subjects in each group were of similar age (HT 46.5±2.01, MT 53.0±1.51, UT 46.7±2.44 years) and lean body mass. Total body weight (kg) and percentage fat, however, were significantly greater ( P <0.05) in the UT group than in either the MT or HT groups (UT 80.6±2.44 kg, 22.0±1.16%; MT 74.9±1.51 kg, 17.5±0.61%; HT 70.5±1.71 kg, 13.5±0.59%). Lumbar vertebrae and hip region BMD (g·cm⁻²) was determined via dual energy X-ray absorptiometry (DEXA). No differences in BMD were found among the three groups in either the lumbar (HT 1.00±0.02, MT 1.02±0.03, UT 1.07±0.04 g·cm⁻²) or the hip regions (HT 0.99±0.03, MT 0.98±0.02, UT 1.06±0.04 g·cm⁻²). Furthermore, none of the groups had BMD that was significantly different from age-matched normative values taken from a reference database. A moderate correlation was found between body weight and BMD when combining all subjects ( r =0.38 for lumbar and r =0.41 for hip). These results indicate that middle-aged to older males who have sustained exercise training in the form of running do not have significantly different lumbar vertebrae or hip region BMD compared to individuals who run less or not at all.