Search

Although body composition is known to influence success in organized sport, the longitudinal body composition changes produced by sport specialization are not well characterized for women's soccer. To address this need, this study reports the body composition changes of NCAA Division I women's soccer players over their entire collegiate playing career. Serial dual-energy x-ray absorptiometry (DXA) scans were performed throughout players' involvement in collegiate women's soccer. Analyses of all players with multiple DXA scans (n 5 80) and players with $3 years of DXA data (n 5 17) were performed using linear mixed-effects models that included effects of time, playing position, game minutes, and interactions. In all athletes (n 5 80; 2.1 6 1.2 years of participation), significant increases in bone mass (1.4%), total lean mass (1.7%), and fat-free mass index (0.3 kg·m-2) occurred. These changes coincided with increased arm and leg bone mass, increased lean mass in all regions, and decreased body fat percentage and leg fat mass. In athletes with $3 years of collegiate data (n 5 17; 3.5 6 0.4 years of participation), larger increases in bone mass (3.0%), bone mineral density (2.2%), total lean mass (2.5%), fat-free mass index (0.4 kg·m-2), and segmental bone and lean mass were observed. Larger decreases in body fat percentage and leg fat mass were also noted. Although playing position was related to body composition characteristics, changes in outcomes were generally unrelated to position or game minutes. In summary, beneficial changes in multiple aspects of body composition were observed over years of participation in a collegiate women's soccer program. [ABSTRACT FROM AUTHOR]

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]

Background: Lower limb bone stress injury (BSI) of the pelvis, femur, and tibia is prevalent in collegiate track and field distance runners. Bone mineral density (BMD), body composition (BComp), and anthropometric parameters before initial collegiate injury have not been compared between runners with BSI and their noninjured counterparts. Purpose: To characterize bone health in relation to BComp and anthropometric measurements from total-body dual x-ray absorptiometry (DXA) scans in collegiate male and female distance runners before BSI and develop BMD prediction models. Study Design: Case-control study; Level of evidence, 3. Methods: Distance runners (N = 79) from a single university track and field team were retrospectively enrolled into this study. The runners completed a DXA scan during the fall season (August-November) and participated in sport activities before the scan. Three months after scanning, electronic medical records were reviewed for the occurrence of BSI. An independent-sample t test was used to compare BMD (total and regional [spine, pelvis, and legs]), BComp (% body fat, fat mass, and lean mass), and anthropometric measurements (shoulder width and leg, arm, and trunk length) between runners with versus without BSI (included subgroup analysis by sex). Multiple linear regression with stepwise removal was used to determine variables most predictive of BMD. Results: Of the 79 enrolled participants (42 male, 37 female), 18 runners (22.8%; 11 female, 7 male) sustained a lower limb BSI. Compared with the noninjured group, injured runners had lower total and regional BMD (P <.001 for all) and shorter leg and arm lengths (P <.05 for both), whereas injured male runners had lower fat mass and injured female runners had lower lean mass in the legs (P <.05 for both). Injured runners' age-matched total BMD Z score (-0.1 ± 0.6) was considered clinically normal. BComp and anthropometric measures were predictive of total and regional BMD (P <.05; R 2 = 0.64-0.80; percentage error = 3.8%-4.8%). Conclusion: The DXA scans of injured runners prior to incidence indicated lower BMD compared with noninjured runners. Shorter limb lengths, lower fat mass (male), and lower leg lean mass (female) may also be indicative of risk. Certain BComp and anthropometric measures were predictive of BMD. [ABSTRACT FROM AUTHOR]

Body composition and bone mineral density of Division 1 collegiate football players: a consortium of college athlete research study. J Strength Cond Res 33(5): 1 3 3 9 - 1346, 2 0 1 9 -T h e purpose of this study was to generate normative data for total and regional body composition in Division 1 collegiate football players using dual-energy x-ray absorptiometry (DXA) and examine positional differences in total and regional measurements. Data were used from the Consortium of College Athlete Research (C-CAR) group. Four hundred sixty-seven players were included in this study. Height, body mass, total and regional fat mass, lean mass, and bone mineral density were measured in each athlete in the preseason (June- August). Players were categorized by their offensive or defensive position for comparisons. Linemen tended to have the higher fat and lean mass measures (p < 0.05 for all) compared with other positions. Positions that mirror each other (e.g. linemen) had similar body composition and body ratios. All positions were classified as overweight or obese based on body mass index (BMI) (> 2 5 k g - r r r 2), yet other than offensive and defensive linemen, all positions had healthy percent body fat (1 3 -2 0% ) and low visceral fat mass (< 5 0 0 g). The data presented here provide normative positional data for total and regional fat mass, lean mass, and bone density in Division 1 collegiate football players. Player position had a significant effect on body composition measures and is likely associated with on-field positional requirements. From a player's health perspective, although all positions had relatively high BMI values, most positions had relatively low body fat and visceral fat, which is important for the health of players during and after their playing career. The increased accuracy and reliability of DXA provides greater information, regarding positional differences in college football players compared with other methods. [ABSTRACT FROM AUTHOR]

Objective: Develop a prediction model for lower extremity long bone injuries (LBIs) in male endurance running athletes using dual-energy x-ray absorptiometry (DEXA). Design: Retrospective. Setting: Sports medicine department in a university athletic setting. Participants: National Collegiate Athletic Association (NCAA) Division 1 white male endurance athletes (n=527). Independent Variables: Backward stepwise elimination was used to achieve a model that predicts LBI, by removing noncontributory variables (P > 0.10), using binary logistic regression. Independent prediction variables analyzed for model were as follows: (1) height (cm), body mass index (BMI) (kg/m-2), and total mass (kg); and (2) regional and total lean mass, fat mass, and bone density assessed using DEXA. Main Outcome Measures: Dichotomous dependent variable was LBI. Results: Final constructed model predicted 96.3% of athletes with and without LBI. Prediction model were as follows: predict lower extremity long bone stress injury = 23.465 - 0.896 BMI + 1.043 (total upper-body mass) TUB - 34.536 leg bone mineral density (BMD). Predict lower extremity long bone stress injury is the LBI prediction, and TUB (kg) is total fat, muscle, and bone weight in trunk and arms. Conclusions: These preliminary data suggest that Division 1 white male endurance running athletes are at risk of LBI with higher relative TUB and lower BMI in combination with a lower leg BMD. [ABSTRACT FROM AUTHOR]