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The purpose of this study was to compare the muscle-to-bone ratio (MBR) in National Collegiate Athletic Association Division I football players (collegiate football players [CFP]) to healthy, age-matched controls. In addition, we examined MBR in CFP by position. A total of 553 CFP and 261 controls had their total and regional lean mass (LM), fat mass (FM), and bone mineral content (BMC) determined by dual x-ray absorptiometry (DXA). College football players were categorized by positions defined as offensive linemen (OL), defensive linemen (DL), tight end, linebacker (LB), running back (RB), punter or kicker, quarterback (QB), defensive back (DB), and wide receiver (WR). There were significant differences between CFP and controls for total LM (80.1 ± 10.0 vs. 56.9 ± 7.8 kg), FM (22.2 ± 12.5 vs. 15.2 ± 7.1 kg), and BMC (4.3 ± 0.5 vs. 3.1 ± 0.5 kg). Although there were significant differences in body composition between CFP and controls, there was no significant differences in total MBR between CFP and controls (18.6 ± 1.4 vs. 18.8 ± 1.7). Regionally, CFP had significantly lower trunk MBR than controls (26.7 ± 2.7 vs. 28.7 ± 4.2), but no difference was seen in leg or arm MBR. Positional differences in CFP were noted as total MBR being significantly higher in DL (19.0 ± 1.4) than in DB (18.1 ± 1.3), WR (18.1 ± 1.3), and LB (18.2 ± 1.3). OL had a significantly higher total MBR (19.2 ± 1.3) than DB(18.1 ± 1.3), LB (18.2 ± 1.3), QB (18.1 ± 1.0), and WR (18.1 ± 1.3). In addition, RB had significantly higher total MBR (18.8 ± 1.3) than DB (18.1 ± 1.3) and WR (18.1 ± 1.3). This study may provide athletes and training staff with normative values when evaluating total and regional MBR with DXA. [ABSTRACT FROM AUTHOR]

Accurate assessments of aerobic capacity are essential to ensuring the health and well-being of firefighters, given their arduous and stressful working conditions. The use of a submaximal protocol, if proven accurate, addresses concerns such as administrative cost, time, and ease of test performance. The purposes of this study were to develop and validate graded submaximal and maximal stairmill protocols and to develop accurate maximal and submaximal equations to predict peak [??][o.sub.2] using both the stairmill and Gerkin treadmill protocols. Fifty-four subjects, men (36.3 [+ or -] 5.6 years) and women (36.4 [+ or -] 6.3 years), performed maximal graded exercise tests using both the stairmill and Gerkin treadmill protocols. Significant predictors of peak [??][o.sub.2] included body mass index, time to completion for maximal protocols, and time to 85% of predicted maximal heart rate for submaximal protocols. Maximal prediction equations were more accurate on both the treadmill ([R.sup.2] = 0.654, standard error of the estimate [SEE] = 3.73 ml x [kg.sup.-1] x [min.sup.-1]) and stairmill ([R.sup.2] = 0.816, SEE = 2.89 ml x [kg.sup.-1] x [min.sup.-1]) than developed submaximal prediction equations for both the treadmill ([R.sup.2] = 0.325, SEE = 5.20 ml x [kg.sup.-1] x [min.sup.-1]) and stairmill ([R.sup.2] = 0.480, SEE = 4.85 ml x [kg.sup.-1] x [min.sup.-1]). Both of the newly developed submaximal prediction equations more accurately predict peak [??][o.sub.2] than the current Gerkin equation. In summary, we support the use of both the stairmill and treadmill as a means for aerobic assessment in this population. The use of the developed submaximal prediction equations should lead to a reduced cost and time of assessment; however, direct measurement of maximal oxygen consumption remains the better alternative. KEY WORDS Gerkin, peak [??}[o.sub.2], heart rate (HR), body mass index (BMI)

Athletic training improves bone mineral density (BMD) through repeated mechanical loading. The location, intensity, and direction of applied mechanical pressure play an important role in determining BMD, making some sports more advantageous at improving BMD at specific regions. Thirty-seven (10 power lifters [PL], 8 Olympic lifters [OL], 8 soccer players [SP], and 11 recreationally active [RA]) women participated in a cross-sectional study. We measured lumbar spine (L1-L4), femoral neck, total-body BMD, and overall body composition (total fat mass, lean mass, percent body fat) with dual-energy x-ray absorptiometry. All athletic groups had greater total BMD than RA (p 5 0.01 [PL]; p, 0.001 [OL]; p 5 0.01 [SP]). Olympic lifters had the highest total BMD than all other athletic groups. Olympic lifters had the significantly greater total BMD than PL (p 5 0.018), but there was no difference in total BMD between PL and SP. As compared with RA, OL showed greater BMD at both the total lumbar spine (p 5 0.002) and the femoral neck (p 5 0.007), whereas PL showed greater BMD only for the total lumbar spine (p 5 0.019) and SP showed greater BMD only for the femoral neck (p 5 0.002). Olympic-style lifting includes both high-impact and odd-impact loading modalities that are associated with the highest BMD at both the lumbar spine and femoral neck. [ABSTRACT FROM AUTHOR]