Body composition changes among female NCAA division 1 athletes across the competitive season and over a multiyear time frame

The Shape of Success: A Scoping Review of Somatotype in Modern Elite Athletes Across Various Sports

This scoping review aimed to determine the somatotype of modern elite athletes across various sports. The literature search followed the PRISMA guidelines for scoping reviews. Four databases were consulted, PubMed, Scopus, Web of Science, and Clarivate InCites, as well as platforms such as Google Scholar, Taylor & Francis Online, Books Ovid, CAB eBooks, MyiLibrary, and Core Collection. Eligibility criteria included articles published between 1995 and 2024 involving athletes at the elite level, such as junior, senior, Olympic, first-division professionals, world-class competitors, national competitors, black belts, master athletes, non-professional athletes with at least 10 years of experience, those ranked in the national or international top 10, and high-level collegiate athletes. A total of 66 studies were included. Modern male elite athletes predominantly exhibited an endomorphic mesomorphic somatotype, whereas female athletes were classified as central. The present study was the first to synthesize data from 66 articles, encompassing athletes of varying elite levels, both males and females, while providing detailed information on age, weight, height, BMI, somatotype and its classification, and complemented by somatoplot references. Future research is recommended to include a greater diversity of sports and a more significant number of elite female athletes to enhance the representativeness of elite athletes.

Off- to in-season body composition adaptations in elite male and female endurance and power event athletics competitors: an observational study

BACKGROUND

Monitoring elite athletes' body composition (BC) is vital for health and optimizing performance in sports emphasizing leanness, such as athletics. This study aims to investigate and compare sex- and event-specific off-to in-season BC changes in endurance and power event athletics competitors.

METHODS

Elite male and female endurance athletes (> 800 m runners; n = 21) and power event athletes (sprinters, jumpers; n = 32) underwent dual-energy X-ray absorptiometry (DXA) scans for whole and regional lean mass (LM), fat mass (FM), bone mineral content (BMC), and density (BMD) during off-season (September-October) and in-season (April-May). Linear mixed models tested between-group off-season differences in BC, within-group off-season to in-season changes, and between-group differences in change. To assess meaningful or least significant changes (LSC) in BC, DXA precision errors were determined from two consecutive total body scans in a subsample of athletes (n = 30).

RESULTS

Male athletes (n = 26) gained significantly (p < 0.05) more body mass (BM; mean difference 1.5 [95% confidence interval (CI):0.5-2.4] kg), LM (843 [95% CI:-253:1459] g), and trunk LM (756 [-502:1156] g) than female athletes (n = 27). The proportion of changes in athlete's BC exceeding the LSC threshold for LM and trunk LM were 70% and 65% in males, and 48% and 26% in females. Significant (p < 0.05) within-group off-season to in-season increases in LM were found for male endurance and power athletes, and female power athletes. All groups significantly increased BMD (p < 0.05). Only male and female power athletes had significant in- to-off-season increases in BMC. 80% of all athletes who had a meaningful increase in BMC belonged to the power event group. No significant within- or between group change in FM was observed.

CONCLUSIONS

The present study found that male athletes gained more BM, LM and trunk LM than females. Within-group increases in regional and whole-body LM and BMC were predominantly found among power event competitors. Incorporating individual meaningful changes alongside traditional statistics provided additional insights into sex and event-group differences. Future research on elite athletic event groups should include DXA measurements closer to major outdoor-season competitions, coupled with site-specific measures (ultrasound, MRI) for better detection of subtle changes in LM and FM.

Application of a New Monitoring Variable: Effects of Power Loss During Squat Training on Strength Gains and Sports Performance

ABSTRACT

Zhang, M, Chen, L, Dai, J, Yang, Q, Huang, Z, He, J, Ji, H, Sun, J, and Li, D. Application of a new monitoring variable: Effects of power loss during squat training on strength gains and sports performance. J Strength Cond Res 38(4): 656-670, 2024-This study aimed to compare the effects of power loss (PL) autoregulated volume (PL10 and PL20) with standardized fixed-load (FL) prescription on strength, sports performance, and lean body mass (LBM). Thirty-five female basketball players from a sports college were randomly assigned to 3 experimental groups (PL10, n = 12; PL20, n = 12; and FL, n = 11, respectively) that performed a resistance training (RT) program with wave-like periodization for 10 weeks using the back squat exercise. Assessments performed before (Pre) and after (Post) intervention included assessed 1 repetition maximum (1RM), body composition, 20-m sprint (T20M), change of direction (COD), and jump performance, including countermovement jump with arm swing, maximum vertical jump, and reactive strength index. Three groups showed significant improvements in strength (effect size [ES]: PL10 = 2.98, PL20 = 3.14, and FL = 1.90; p < 0.001) and jump performance (ES: PL10 = 0.74, PL20 = 1.50, and FL = 0.50; p <0.05-0.001). However, PL10 and PL20 demonstrated different advantages in sports performance compared with FL (group × time interaction, p <0.05). Specifically, PL10 significantly improved COD performance (ES = -0.79 ∼ -0.53, p <0.01), whereas PL20 showed greater improvements in sprint (ES = -0.57, p <0.05) and jump performance (ES = 0.67-1.64, p <0.01-0.001). Moreover, PL10 resulted in similar gains to PL20 and beneficial improvements compared with FL in LBM, despite performing the least repetitions. Overall, the study indicates that power loss-based autoregulation induces greater gains in LBM and sports performance, as well as eliciting a higher efficiency dose response than standardized FL prescriptions, particularly for PL10. Therefore, incorporating PL monitoring in training programs is recommended, and further studies on power-based RT would be worthwhile.

Tracking Body Composition Over a Competitive Season in Elite Soccer Players Using Laboratory- and Field-Based Assessment Methods

ABSTRACT

Bongiovanni, T, Lacome, M, Rodriguez, C, and Tinsley, GM. Tracking body composition over a competitive season in elite soccer players using laboratory- and field-based assessment methods. J Strength Cond Res 38(3): e104-e115, 2024-The purpose of this study was to describe body composition changes in professional soccer players over the course of a competitive playing season and compare the ability of different assessment methods to detect changes. Twenty-one elite male soccer players (age: 23.7 ± 4.8 years; height: 185.0 ± 5.2 cm; body mass: 80.7 ± 5.5 kg; body fat: 12.8 ± 2.2%) playing for an Italian national second league (Serie B) championship team were assessed at 4 time points throughout a competitive season: T0 (mid-October), T1 (mid-December), T2 (mid-February), and T3 (end of April). Dual-energy x-ray absorptiometry (DXA), skinfolds (SKF), and bioelectrical impedance analysis were performed at each time point, and multiple SKF-based equations were applied. A modified 4-compartment (4C) model was also produced. Data were analyzed using repeated measures analysis of variance, relevant post hoc tests, and Pearson's correlations. Dual-energy x-ray absorptiometry, 4C, and the SKF-based equations of Reilly and Civar detected differences in fat-free mass (FFM) between time points, with the most differences observed for DXA. Fat-free mass increased from T0 values to a peak at T2, followed by a decrease by T3, although FFM values remained higher than T0. Fat-free mass gain was primarily driven by increases in the lower limbs. Fat-free mass changes between all methods were significantly correlated, with correlation coefficients of 0.70-0.97. No significant differences between time points were observed for absolute fat mass or body fat percentage, although significant correlations between several methods for change values were observed. Select laboratory and field methods can detect changes in FFM over the course of a season in elite, professional soccer athletes, with a more limited ability to detect changes in adiposity-related variables. For SKF in this population, the equation of Reilly is recommended.

Development and validation of a rapid multicompartment body composition model using 3-dimensional optical imaging and bioelectrical impedance analysis

BACKGROUND & AIMS

The multicompartment approach to body composition modeling provides a more precise quantification of body compartments in healthy and clinical populations. We sought to develop and validate a simplified and accessible multicompartment body composition model using 3-dimensional optical (3DO) imaging and bioelectrical impedance analysis (BIA).

METHODS

Samples of adults and collegiate-aged student-athletes were recruited for model calibration. For the criterion multicompartment model (Wang-5C), participants received measures of scale weight, body volume (BV) via air displacement, total body water (TBW) via deuterium dilution, and bone mineral content (BMC) via dual energy x-ray absorptiometry. The candidate model (3DO-5C) used stepwise linear regression to derive surrogate measures of BV using 3DO, TBW using BIA, and BMC using demographics. Test-retest precision of the candidate model was assessed via root mean square error (RMSE). The 3DO-5C model was compared to criterion via mean difference, concordance correlation coefficient (CCC), and Bland-Altman analysis. This model was then validated using a separate dataset of 20 adults.

RESULTS

67 (31 female) participants were used to build the 3DO-5C model. Fat-free mass (FFM) estimates from Wang-5C (60.1 ± 13.4 kg) and 3DO-5C (60.3 ± 13.4 kg) showed no significant mean difference (-0.2 ± 2.0 kg; 95 % limits of agreement [LOA] -4.3 to +3.8) and the CCC was 0.99 with a similar effect in fat mass that reflected the difference in FFM measures. In the validation dataset, the 3DO-5C model showed no significant mean difference (0.0 ± 2.5 kg; 95 % LOA -3.6 to +3.7) for FFM with almost perfect equivalence (CCC = 0.99) compared to the criterion Wang-5C. Test-retest precision (RMSE = 0.73 kg FFM) supports the use of this model for more frequent testing in order to monitor body composition change over time.

CONCLUSIONS

Body composition estimates provided by the 3DO-5C model are precise and accurate to criterion methods when correcting for field calibrations. The 3DO-5C approach offers a rapid, cost-effective, and accessible method of body composition assessment that can be used broadly to guide nutrition and exercise recommendations in athletic settings and clinical practice.

Changes in Body Composition and Athletic Performance in National Collegiate Athletic Association Division I Female Field Hockey Athletes Throughout a Competitive Season

ABSTRACT

Summer, LC, Cheng, R, Moran, JT, Lee, M, Belanger, AJ, TaylorIV, WL, and Gardner, EC. Changes in body composition and athletic performance in National Collegiate Athletic Association Division I female field hockey athletes throughout a competitive season. J Strength Cond Res 38(1): 146-152, 2024-The purposes of this study were (a) to analyze the changes in total and regional body composition measurements in a National Collegiate Athletic Association (NCAA) Division I female field hockey team throughout a 17-game competitive season using dual X-ray absorptiometry (DXA); (b) to examine improvements, if any, in athletic performance measures after a season; and (c) to report on the relationship between these body composition changes and changes in athletic performance. Preseason and postseason dual-energy DXA and performance data from the 2019-2020 season were retrospectively identified for 20 field players (forwards, midfielders, and defenders). Body composition data included total and regional fat mass, lean mass, and body fat percentage, whereas athletic performance measures included the vertical jump, 10-yard dash, and pro-agility (5-10-5) shuttle run. All variables were quantitative and analyzed using paired t -tests or its nonparametric equivalent and an alpha level of p < 0.05 was used to determine significance. After a competitive season, athletes had significant decreases in fat mass and increases in lean mass in their arms, legs, trunks, gynoids, and total body measurements. Android fat mass and body fat percentage also decreased. Athletes performed significantly better on the pro-agility shuttle run at the end of the season, but no significant differences were observed in other performance metrics. Moderate correlations were observed between changes in body composition (total fat mass and total lean mass) and changes in athletic performance. Our study provides a novel, longitudinal assessment of body composition and athletic performance for elite female field hockey athletes that will help trainers and coaches better understand how these variables change throughout a season and allow them to better prepare their players for competitive success.

Accuracy and precision of multiple body composition methods and associations with muscle strength in athletes of varying hydration: The Da Kine Study

BACKGROUND

Athletes vary in hydration status due to ongoing training regimes, diet demands, and extreme exertion. With water being one of the largest body composition compartments, its variation can cause misinterpretation of body composition assessments meant to monitor strength and training progress. In this study, we asked what accessible body composition approach could best quantify body composition in athletes with a variety of hydration levels.

METHODS

The Da Kine Study recruited collegiate and intramural athletes to undergo a variety of body composition assessments including air-displacement plethysmography (ADP), deuterium-oxide dilution (D2O), dual-energy X-ray absorptiometry (DXA), underwater-weighing (UWW), 3D-optical (3DO) imaging, and bioelectrical impedance (BIA). Each of these methods generated 2- or 3-compartment body composition estimates of fat mass (FM) and fat-free mass (FFM) and was compared to equivalent measures of the criterion 6-compartment model (6CM) that accounts for variance in hydration. Body composition by each method was used to predict abdominal and thigh strength, assessed by isokinetic/isometric dynamometry.

RESULTS

In total, 70 (35 female) athletes with a mean age of 21.8 ± 4.2 years were recruited. Percent hydration (Body Water6CM/FFM6CM) had substantial variation in both males (63-73 %) and females (58-78 %). ADP and DXA FM and FF M had moderate to substantial agreement with the 6C model (Lin's Concordance Coefficient [CCC] = 0.90-0.95) whereas the other measures had lesser agreement (CCC <0.90) with one exception of 3DO FFM in females (CCC = 0.91). All measures of FFM produced excellent precision with %CV < 1.0 %. However, FM measures in general had worse precision (% CV < 2.0 %). Increasing quartiles (significant p < 0.001 trend) of 6CM FFM resulted in increasing strength measures in males and females. Moreover, the stronger the agreement between the alternative methods to the 6CM, the more robust their correlation with strength, irrespective of hydration status.

CONCLUSION

The criterion 6CM showed the best association to strength regardless of the hydration status of the athletes for both males and females. Simpler methods showed high precision for both FM and FFM and those with the strongest agreement to the 6CM had the highest strength associations.

SUMMARY BOX

This study compared various body composition analysis methods in 70 athletes with varying states of hydration to the criterion 6-compartment model and assessed their relationship to muscle strength. The results showed that accurate and precise estimates of body composition can be determined in athletes, and a more accurate body composition measurement produces better strength estimates. The best laboratory-based techniques were air displacement plethysmography and dual-energy x-ray absorptiometry, while the commercial methods had moderate-poor agreement. Prioritizing accurate body composition assessment ensures better strength estimates in athletes.

Body fat of competitive volleyball players: a systematic review with meta-analysis

BACKGROUND

Reference values of body fat for competitive volleyball players are lacking, making it difficult to interpret measurement results. This review systematically summarized published data on the relative body fat of volleyball players and calculated potential differences between sex, measurement method, and competitive level.

METHODS

The protocol followed the Preferred Reported Items for Systematic Reviews and Meta-Analysis guidelines. The literature search was conducted using five electronic databases to retrieve all relevant publications from January 1, 2010, to July 1, 2021. The 63 studies including 2607 players that met the inclusion criteria were analyzed using random-effects models. Data were reported as pooled mean body fat with 95% confidence intervals.

RESULTS

Body fat for males and females was 12.8% (11.9-13.8%) and 22.8% (21.9-23.7%), respectively. Body fat was 18.3% (16.3-20.4%) measured via skinfolds, 18.4% (15.6-21.2%) via bioelectrical impedance analysis, 24.2% (20.4-28.0%) via dual-energy x-ray absorptiometry and 21.6% (17.4-25.8%) via densitometry. Regional, national, and international-level players had body fat values of 19.5% (17.8-21.2%), 20.3% (18.6-22.0%), and 17.9% (15.7-20.4%), respectively. When the meta-regression was adjusted for the variables sex, measurement method, and competitive level, a significant difference between sex (p < 0.001), dual-energy x-ray absorptiometry and skinfolds (p = 0.02), and national and international-level players (p = 0.02) was found. However, sensitivity analysis revealed that findings regarding measurement method and competitive level were not robust and should, therefore, be interpreted with caution.

CONCLUSIONS

Despite the limitations of published data, this meta-analysis provided pooled values for body fat of male and female volleyball players for different competitive levels and measurement methods.

Energy balance and energy availability of female basketball players during the preparation period

OBJECTIVE

To determine the level of energy balance and energy availability (EA) in female basketball players during the preparation period.

METHODS

Fifteen basketball players (age: 19.53 ± 1.3 years; height: 173.6 ± 8.95 cm; weight: 67.55 ± 14.34 kg; training experience: 9.6 ± 2.7 years) and 15 age and body mass index-matched controls (age: 19.53 ± 1.1 years; height: 169.4 ± 5.06 cm; weight: 63.10 ± 6.14 kg) participated in the study. Resting metabolic rate (RMR) and body composition were measured by the indirect calorimetric method and dual-energy x-ray absorptiometry, respectively. A 3-day food diary was used to determine macronutrients and energy intake while a 3-day physical activity log was used to determine energy expenditure. Independent Samples t-test was used for data analysis.

RESULTS

The daily energy intake and expenditure of female basketball players were 2136.5 ± 594.9 kcal·day-1 and 2953.8 ± 614.5 kcal·day-1, respectively, indicating 817 ± 779 kcal·day-1 of negative energy balance. One hundred percent and 66.6% of the athletes failed to meet the carbohydrate and protein intake recommendations, respectively. EA of female basketball players was 33.04 ± 15.69 kcal·fat free mass-1·day-1 and the percentages of athletes who had negative energy balance, low EA, and reduced EA were 80%, 40%, and 46.7%, respectively. However, despite the low and decreased EA, the measured RMR to predicted RMR ratio (RMRratio) was 1.31 ± 0.17 and the body fat percentage (BF%) was 31.00 ± 5.21%.

CONCLUSION

This study shows that female basketball players have a negative energy balance during the preparation period which can be partly explained by insufficient carbohydrate intake. Although most of the athletes experienced low or reduced EA during the preparation period, the physiologically normal RMRratio and relatively high BF% indicate that this is a transient situation. In this regard, strategies to prevent the development of low EA and negative energy balance during the preparation period will contribute to positive training adaptations throughout the competition period.

Dynamic balance and explosive strength appears to better explain single leg hop test results among young elite female basketball athletes

To analyze the impact of balance, lower-limb explosive strength and anthropometric variables on the result of the hop test in young elite female basketball athletes. Ninety young elite female basketball athletes (13-17 years), without current or recent lower-limb injury, were assessed in the off-season period of July 2021. Single leg hop test, countermovement jump, Y balance test and anthropometric outcomes were assessed. A correlation study and a regression model were performed to investigate the influence of such outcomes and the value of their participation on the hop test results. It was found a low-to-moderate correlation effect size for both countermovement jump (distance and power flight) and Y balance test values (except interlimb outcomes) with the single leg hop test results. Anthropometric outcomes did not show significant correlation (p > 0.05). Regression model revealed that for right hop test, countermovement jump values exhibited an adjusted determination coefficient of 0.408, (β = 0.249, p = 0.013), For left hop test, again the countermovement jump values (β = 0.229, p = 0.025), and left Y balance test values (β = 0.331, p = 0.011) jointly obtained an adjusted determination coefficient of 0.263 significant predictive value for countermovement jump outcomes in both right (β = 0.249, p = 0.013; β = 0.301; p = 0.031) and left leg (β = 0.229, p = 0.025; β = 0.365, p = 0.040), as well as certain Y balance outcomes values. Explosive strength, and dynamic balance although to a lesser extent, appear to be the most relevant physical-functional factors influencing the single leg hop test results among young elite female basketball athletes. These findings may a serve as a basis to implement targeted interventions, such as plyometric and balance training, for an enhancement on functional rehabilitation and reducing the risk of injury related to the hop test results.

Changes in Body Composition and Motor Fitness of Young Female Volleyball Players in an Annual Training Cycle

BACKGROUND

Modern volleyball requires a high level of motor preparation, specific body build and optimal body composition.

OBJECTIVES

The aim of this study was to determine changes in body build, body composition and motor skills in young volleyball female players during an annual training cycle.

METHODS

The research group was comprised of 36 female athletes aged 14-16 years, who were monitored throughout a whole season using a longitudinal study design. Body composition was estimated by bioelectrical impedance analysis. Motor fitness was assessed with the following tests: vertical jumping tests (based on one-handed and two-handed reach, standing vertical jump and running vertical jump), standing long jump and 2 kg medicine ball throw. Measurements were carried out at the beginning of the preparatory period, after its completion, in the middle of the start period, at the end of the start period and during transition periods.

RESULTS

The study showed significant changes in body composition and motor fitness level during the annual training cycle. These changes differ in subsequent periods of the macrocycle. The most pronounced changes occurred after the preparatory period and concerned increases in fat-free mass, total water content and cell mass. A significant reduction in fat content was also noted at this point.

CONCLUSIONS

Systematic monitoring of morpho-functional changes in young female volleyball players over extended periods provides them a chance to maintain their optimal fitness level.

Season-Long Changes in the Body Composition Profiles of Competitive Female Rugby Union Players Assessed via Dual Energy X-Ray Absorptiometry

Background: Reference data for the body composition values of female athletes are limited to very few sports, with female Rugby Union players having mostly been omitted from such analyses.Methods: Using dual energy X-ray absorptiometry (DXA) scans, this study assessed the body composition profiles (body mass, bone mineral content; BMC, fat mass; FM, lean mass; LM, bone mineral density; BMD) of 15 competitive female Rugby Union players before and after the 2018/19 competitive season. Total competitive match-play minutes were also recorded for each player.Results: Body mass (73.7 ± 9.6 kg vs 74.9 ± 10.2 kg, p ≤ 0.05, d = 0.13) and BMC (3.2 ± 0.4 kg vs 3.3 ± 0.4 kg, p ≤ 0.05, d = 0.15) increased pre- to post-season for all players. Conversely, FM (21.0 ± 8.8 kg), LM (50.7 ± 3.9 kg), and BMD (1.31 ± 0.06 g·cm^-2) were similar between time-points (all p > .05). Accounting for position, body mass (r_partial(12) = 0.196), FM (r_partial(12) = -0.013), LM (r_partial(12) = 0.351), BMD (r_partial(12) = 0.168) and BMC (r_partial(12) = -0.204) showed no correlation (all p > .05) against match-play minutes.Conclusion: The demands of the competitive season influenced specific body composition indices (i.e., body mass, BMC) in female Rugby Union players; a finding which was unrelated to the number of minutes played in matches. While the causes of such differences remain unclear, practitioners should be cognizant of the body composition changes occurring throughout a female Rugby Union competitive season and, where necessary, consider modifying variables associated with adaptation and recovery accordingly.

Assessing Dietary Nutrient Adequacy and the Effect of Season-Long Training on Body Composition and Metabolic Rate in Collegiate Male Basketball Players

The success of performance in basketball relies on both optimal body composition and nutrient intake. The purpose of this study was to examine seasonal changes in body composition (BC), resting metabolic rate (RMR) and respiratory quotient (RQ), as well as dietary intake of National Collegiate Athletic Association (NCAA) Division I (DI) male basketball players. BC, RMR and RQ were assessed during pre-season, in-season, and post-season (September, December, and March) while dietary assessment data were collected in September and February. Results of this study indicated that players received inadequate energy (p < 0.0001), protein (p < 0.001) and carbohydrate (p < 0.0001) relative to the recommendations for exercising individuals during the September baseline period. However, following diet analysis and consultations and relative to recommendations, athletes received adequate amounts of energy and protein during follow-up, yet intakes of carbohydrate (p = 0.0025) were still significantly different than recommended. Results also indicated that there was a decrease in percent body fat (%BF) during season, an increase in lean body mass (LBM) from pre- to post-season, a peak in RMR during season and an increase in RQ post-season. These findings reveal that significant metabolic and body composition changes occur in players over the season and suggest that nutritional strategies employed concomitantly may be beneficial.

Evaluation of 10-Week Neuromuscular Training Program on Body Composition of Elite Female Soccer Players

(1) Background: This study was conducted to investigate the effects of a 10-week neuromuscular training program (NMT) on the sum of six skinfolds (Σ6S) and body composition variables in elite female soccer players. (2) Methods: Forty-four Spanish elite female soccer players (age: 24.0 ± 4.2 years; height: 164.3 ± 5.5 cm; body mass: 60.4 ± 5.5 kg; body mass index (BMI): 22.4 ± 2.2 kg/m²) were randomly assigned to a control group (CG) or to an experimental group (EG). Participants in the EG completed a specific NMT program of 24 min, three times per week, which included exercises from six different categories (mobility, dynamic stability, anterior chain strength, lumbopelvic control, posterior chain strength, and change of direction). The CG followed their normal strength and conditioning program. Pre- and post-intervention assessments included anthropometric measurements (weight, height, limb circumferences, and bone breadths), and subsequently, body composition factors BMI, Σ6S, body mass, muscle mass, and lean body mass were calculated. Nutrition was standardized by a nutritionist and also load monitored. (3) Results: A two-way mixed analysis of variance (group × time) revealed that there was a significant (p ≤ 0.001) group × time interaction between body mass, fat mass, and Σ6S in favor of NMT. A significant interaction was also observed for body skeletal muscle mass and lean body mass favoring NMT. (4) Conclusions: The application of an NMT program seems to be a useful strategy to improve body composition in elite female soccer players.

Body Composition Values of NCAA Division 1 Female Athletes Derived From Dual-Energy X-Ray Absorptiometry

ABSTRACT

Dobrosielski, DA, Leppert, KM, Knuth, ND, Wilder, JN, Kovacs, L, and Lisman, PJ. Body composition values of NCAA Division 1 female athletes derived from dual-energy x-ray absorptiometry. J Strength Cond Res 35(10): 2886-2893, 2021-This study generated descriptive data for regional and total body composition and bone mineral density (BMD) measures using dual-energy x-ray absorptiometry (DXA) across 12 NCAA Division 1 female competitive sports. Two hundred seventy-eight female collegiate athletes underwent DXA: basketball (BB; n = 28), cross country (CC = 11), field hockey (FH; n = 35), gymnastics (GYM; n = 23), lacrosse (LAX; n = 48), soccer (SOC; CC = 27), softball (SB; n = 24), swimming and diving (SW; n = 35), tennis (TN; n = 11), track and field ([TR-throw; n = 10]; [TR-run; n = 10]), and volleyball (VB; n = 16). Descriptive statistics for all body composition and BMD measures were calculated. Group mean differences in all regional and total body composition (all, p < 0.001; η2 range = 0.177-0.365) and BMD (all, p < 0.001; η2 range = 0.317-0.383) measures were observed between teams. The total BF% for gymnasts (23.5%) was lower than TN, FH, LAX, SB, and TR-throw (mean difference range: -4.6 to -12.9%, all p < 0.01); TR-throw had the highest total BF% (36.4%). Cross country had lower total BMD (1.17 g·cm-2) than FH, TR-throw, LAX, GYM, SOC, SB, VB, and BB (mean difference range: -0.12 to -0.26 g·cm-2, all p < 0.01); BB and TR-throw had the highest total BMD (1.40 and 1.43 g·cm-2, respectively). Our data confirm that regional and total body composition and BMD measures varied across female collegiate sports. These findings may assist sports medicine and strength and conditioning practitioners with identifying sport-specific goal values for BF% and BMD to optimize program design.

Training Demands and Physiological Profile of Cross-Disciplined Collegiate Female Dancers

ABSTRACT

Sanders, DJ, Walker, AJ, Prior, KE, Poyssick, AN, and Arent, SM. Training demands and physiological profile of cross-disciplined collegiate female dancers. J Strength Cond Res 35(8): 2316-2320, 2021-Little is known about the physical demands of high-level dance training. Therefore, the purpose of this study was to investigate the physiological demands of a typical ballet and modern class through training load (TL) and to assess differences in TL between the 2 class types. In addition, a physiological profile of cross-disciplined collegiate female dancers was determined. Seventeen college-aged female dancers were recruited and performed a battery of performance tests assessing body fat (%BF), lean body mass, vertical jump (VJ), peak power, maximal oxygen consumption (V̇o2max), and ventilatory threshold (VT). Two ballet and modern dance classes were monitored for TL and exercise energy expenditure (EEE) using the Polar Team2 Pro System. Performance testing results were as follows: M%BF = 24.1 ± 4.2%, MLBM = 46.8 ± 8.5 kg, MV̇o2max = 42.9 ± 4.3 ml·kg-1·min-1, MVT = 76.2 ± 6.5% of V̇o2max, MVJ = 44.1 ± 1.4 cm, and MPP = 519.1 ± 177.5 W. Training load of 41.0 ± 17.0 for ballet and 44.8 ± 27.4 for modern dance was found, with an EEE of 394.0 ± 111.9 and 421.9 ± 161.4 kcal, respectively. Time spent at or above VT was 1.2 ± 2.6 minutes in ballet and 3.4 ± 8.3 minutes in modern. Compared with other female power-endurance athletes, the dancers accumulated a much lower TL during both class types. Low TL may inhibit typical adaptations seen in other athletes, which may explain why dancers in this study had lower aerobic and anaerobic capacities and higher body fat percentage than other collegiate female athletes. Also, it suggests that supplemental conditioning could be incorporated into a dancers training paradigm to optimize performance.

Food Choice Decisions of Collegiate Division I Athletes: A Qualitative Exploratory Study

Limited research has examined athletes’ food and health beliefs and decisions and the congruence of these decisions with recommendations from nutrition professionals. This study aimed to improve understanding of athletes’ food-related beliefs and practices to enable nutrition professionals to more effectively enhance performance while protecting athletes’ health. Division I college athletes (n = 14, 64% female) from a variety of sports were recruited to participate in 20-min semi-structured phone interviews about food and nutrition-related behaviors and cognitions. Data were content analyzed to identify themes and trends. Prominent factors influencing athletes’ food choices were potential benefits to health and performance, availability of foods, and recommendations from sports dietitians. Foods commonly consumed by athletes, including fruits, vegetables, and lean protein, were generally healthy and aligned with sports nutrition recommendations. Athletes avoided energy-dense nutrient-poor foods, such as fast food and fried foods, with the goal of improving performance. Some athletes took supplements (i.e., multivitamin, iron, protein) on the premise that they would improve health and enhance performance or recovery. While athletes’ nutrition behaviors are generally congruent with current recommendations, findings highlighted misconceptions held by athletes related to the benefits of some supplements and the belief that packaged/processed foods were inherently less healthy than other options. Nutrition misconceptions held by athletes and incongruities between athletes’ nutrition knowledge and behaviors suggest that dietitians should aim to dispel misconceptions held by athletes and provide additional guidance and information to support athletes’ current healthful behaviors to ensure these behaviors extend beyond their college athletic career.

Physiological Characteristics of Female Soccer Players and Health and Performance Considerations: A Narrative Review

Female soccer has seen a substantial rise in participation, as well as increased financial support from governing bodies over the last decade. Thus, there is an onus on researchers and medical departments to develop a better understanding of the physical characteristics and demands, and the health and performance needs of female soccer players. In this review, we discuss the current research, as well as the knowledge gaps, of six major topics: physical demands, talent identification, body composition, injury risk and prevention, health and nutrition. Data on female talent identification are scarce, and future studies need to elucidate the influence of relative age and maturation selection across age groups. Regarding the physical demands, more research is needed on the pattern of high-intensity sprinting during matches and the contribution of soccer-specific movements. Injuries are not uncommon in female soccer players, but targeting intrinsically modifiable factors with injury prevention programmes can reduce injury rates. The anthropometric and physical characteristics of female players are heterogeneous and setting specific targets should be discouraged in youth and sub-elite players. Menstrual cycle phase may influence performance and injury risk; however, there are few studies in soccer players. Nutrition plays a critical role in health and performance and ensuring adequate energy intake remains a priority. Despite recent progress, there is considerably less research in female than male soccer players. Many gaps in our understanding of how best to develop and manage the health and performance of female soccer players remain.

Body composition in professional female netball players within and between seasons: a cohort study

Background

There is limited information on the physique attributes of female netball players from the highest playing standards and the typical body composition changes that occur with training and competition in these athletes. The purpose of this study was to examine the body composition of professional female netball players and changes that occur within and between national premier netball seasons.

Methods

Dual-energy X-ray absorptiometry (DXA) assessments were conducted in 20 female netball players (age = 26.5 [4.7] years, body mass = 77.3 [9.7] kg, stature = 182.7 [9.5] cm) contracted to a Suncorp Super Netball team. Total body lean mass, fat mass, bone mass and bone mineral density were derived for 127 assessments collected over three seasons. Linear mixed effects modelling was used to examine changes in body composition measures within and between seasons.

Results

Goal circle players were heavier (12.3 [3.5] kg, p < 0.001, g = 1.51) and taller (15.0 [2.7] cm, p < 0.001, g = 2.30) than midcourt players, and midcourt players had greater lean mass (3.1 [1.6] %, p = 0.07, g = 0.85) and less fat mass (-3.3 [1.7] %, p = 0.06, g = -0.84) than goal circle players when values were normalised to body mass. Players achieved increases in lean mass (2,191 [263] g, p < 0.01, g = 0.45) and decreases in fat mass (-835 [351] g, p = 0.09, g = -0.16) following a preseason preparation period. There were no changes in lean mass (-394 [295] g, p = 0.54, g = 0.07) or fat mass (102 [389] g, p = 0.99, g = 0.04) from the start to the end of the 14-week competition period.

Conclusions

Professional female netball players achieve small changes in lean mass and fat mass during preseason preparation and maintain their physique over the competitive season. The results of this study can inform practitioners on the training content necessary to promote or maintain desired body composition changes in these athletes.

New Frontiers of Body Composition in Sport

The body composition phenotype of an athlete displays the complex interaction among genotype, physiological and metabolic demands of a sport, diet, and physical training. Observational studies dominate the literature and describe the sport-specific physique characteristics (size, shape, and composition) of adult athletes by gender and levels of competition. Limited data reveal how body composition measurements can benefit an athlete. Thus, the objective is to identify purposeful measurements of body composition, notably fat and lean muscle masses, and determine their impact on the health and performance of athletes. Areas of interest include relationships among total and regional body composition measurements, muscle function, sport-specific performance, risk of injury, return to sport after injury, and identification of activity-induced fluid shifts. Discussion includes the application of specific uses of dual X-ray absorptiometry and bioelectrical impedance including an emphasis on the need to minimize measurement errors and standardize protocols, and highlights opportunities for future research. This focus on functional body composition can benefit the health and optimize the performance of an athlete.

Anthropometric Dimensions and Bone Quality in International Male Beach Handball Players: Junior vs. Senior Comparison

BACKGROUND

Beach handball is a recent team sport characterized by defensive and offensive actions on a sand surface. Scientific evidence has shown that body composition is fundamental in sports performance. The main objective of this study was to know the body composition, anthropometric characteristics, and bone mineral density of elite beach handball players. Furthermore, another purpose was to analyze the differences between categories (junior and senior) and playing position. Methods: A descriptive, cross-sectional study of 36 male players (18 juniors and 18 seniors) of the Spanish National Beach Handball Team was conducted. Full profile anthropometry and calcaneal ultrasound measurements were used. Results: Significant differences between categories (p < 0.05) were found in: height, body mass, arm span, BMI, muscle mass, fat mass, bone mass, skinfolds, and body perimeters. The somatotype changes depending on the playing position. Bone mineral density of the players was adequate. No significant differences were found by playing position. Conclusions: Senior players had a better body composition due to the presence of less fat mass than junior players. This study provides reference values of elite junior and senior beach handball players and by playing positions. This data is useful for the identification of talents and players who should be trained to improve their body composition.

Mediterranean Diet Adherence, Body Composition and Performance in Beach Handball Players: A Cross Sectional Study

BACKGROUND

Beach handball (BH) is a sport in which sporting performance is influenced, together with team interaction, by individual performance in terms of strength. Body composition is one of the main factors for sports performance and eating habits can condition this variable. The Mediterranean diet (MD) can significantly reduce the risk of mortality or cardiovascular disease. In addition, the Spanish Ministry of Agriculture, Food and Environment carries out different campaigns to promote it among young athletes, establishing it as a suitable diet for sports.

OBJECTIVES

The main aims of the study are to assess body composition, physical activity and adherence to the MD of beach handball players. It also aims to evaluate age group differences in male and female players, as well as studying the possible relationship between MD, body composition and performance variables.

METHODS

A total of 59 Spanish BH players were recruited in the national championship of BH in the province of Alicante. Thirty-eight male (14 junior; 17.0 ± 0.1 years and 24 seniors; 25.5 ± 4.7 years) and twenty-one female (7 junior; 16.1 ± 1.46 years and 14 seniors; 23.2 ± 2.0 years) BH players participated in this study. The questionnaire to evaluate eating habits was Mediterranean diet adherence (KIDMED). Body composition was measured with electrical bioimpedance. Strength was evaluated by means of a maximum isometric handgrip test of the dominant hand with handgrip and height of jump by counter-jump on contact platform. In the statistical analysis, descriptions and correlations between the study variables were made.

RESULTS

In females, when the adherence to the MD is lower, the weight is higher, the lean body mass is lower and worse results are observed in performance tests. As for males, there are differences in weight and lean body mass according to category.

CONCLUSIONS

Adequate eating habits are related to the weight of beach handball athletes. In addition, specifically with junior players, it has been observed that adherence to the MD correlates with weight.

Positional Body Composition of Female Division I Collegiate Volleyball Players

Bisch, KL, Bosch, TA, Carbuhn, A, Stanforth, PR, Oliver, JM, Bach, CW, and Dengel, DR. Positional body composition of female division I collegiate volleyball players. J Strength Cond Res 34(11): 3055-3061, 2020-The primary study objective was to measure positional differences in total and regional body composition among female NCAA Division I collegiate volleyball players using dual X-ray absorptiometry (DXA). The secondary objective was to examine normative age curves for fat and lean mass (LM) variables. Ninety female volleyball players from 5 universities received a DXA scan. Athletes were categorized by position: middle blocker (MB = 31), outside hitter (OH = 32), setter (ST = 9), and Libero (LB = 18). Height, body mass, total and regional fat mass (FM), LM, bone mineral density (BMD), and abdominal visceral adipose tissue were measured by DXA. Body mass distribution ratios were calculated. The secondary age analysis included a subset of 153 DXA scans (n = 83, ages 18-21 years). Front row players (i.e., MB and OH) had significantly greater total and regional LM and BMD measures (p < 0.05, all), compared with non-front row players (i.e., LB and ST). Differences in total LM (p < 0.001) were significantly influenced by height. Front row players had consistently lower mass distribution ratios compared with non-front row players (p < 0.05, all). Lean mass index (LMI, p = 0.752) and FM index (FMI, p = 0.392) were not significantly different across ages. Back row players have greater relative upper body mass, whereas mass in front row players is more evenly distributed between the upper and lower body. Bone mineral density differences may be influenced by repeated impact of jumping during the attacking and blocking actions of front row players. Minimal changes in LMI and fluctuations in FMI can be expected across an athlete's career.

Effects of Probiotic (Bacillus subtilis) Supplementation During Offseason Resistance Training in Female Division I Athletes

Toohey, JC, Townsend, JR, Johnson, SB, Toy, AM, Vantrease, WC, Bender, D, Crimi, CC, Stowers, KL, Ruiz, MD, VanDusseldorp, TA, Feito, Y, and Mangine, GT. Effects of probiotic (Bacillus subtilis) supplementation during offseason resistance training in female Division I athletes. J Strength Cond Res 34(11): 3173-3181, 2020-We examined the effects of probiotic (Bacillus subtilis) supplementation during offseason training in collegiate athletes. Twenty-three Division I female athletes (19.6 ± 1.0 years, 67.5 ± 7.4 kg, and 170.6 ± 6.8 cm) participated in this study and were randomized into either a probiotic (n = 11; DE111) or placebo (n = 12; PL) group while counterbalancing groups for sport. Athletes completed a 10-week resistance training program during the offseason, which consisted of 3-4 workouts per week of upper- and lower-body exercises and sport-specific training. Athletes consumed DE111 (DE111; 5 billion CFU/day) or PL supplement daily for the entire 10-week program. Before and after training, all athletes underwent 1 repetition maximum (1RM) strength testing (squat, deadlift, and bench press), performance testing (vertical jump and pro-agility), and isometric midthigh pull testing. Body composition (body fat [BF]%) was completed using BODPOD and bioelectrical impedance analysis, as well as muscle thickness (MT) measurement of the rectus femoris (RF) and vastus lateralis using ultrasonography. Separate repeated-measures analyses of variance were used to analyze all data. Significant (p ≤ 0.05) main effects for time were observed for improved squat 1RM, deadlift 1RM, bench press 1RM, vertical jump, RF MT, and BF%. Of these, a significant group × time interaction was noted for BF% (p = 0.015), where greater reductions were observed in DE111 (-2.05 ± 1.38%) compared with PL (-0.2 ± 1.6%). No other group differences were observed. These data suggest that probiotic consumption in conjunction with post-workout nutrition had no effect on physical performance but may improve body composition in female Division I soccer and volleyball players after offseason training.

Body Composition Changes over Multiple Academic Years in Female Collegiate Soccer Players

Body composition plays a key role in overall health and sports performance and its assessment is an important part of many athletic programs. The purpose of this study was to describe longitudinal changes in body composition for collegiate female soccer players in order to provide data to inform future training and nutrition interventions for this population. A linear mixed-model (LMM) approach was used to analyze four years of pre- and post-season body composition data, including total mass, fat-free mass (FFM), fat mass, and body fat percentage (%BF) for 49 athletes. Athletes gained an average of 0.5 kg FFM during the season (p < 0.05) and increased total mass, FFM, fat mass, and %BF (2.5 kg, 1.1 kg, 1.7 kg, and 1.7%, respectively; p < 0.05) over four years. Freshmen experienced a 1.5 kg gain in total mass pre- to post-season (p < 0.05), while no changes in total mass or body composition were seen in other grade levels. Gains in %BF during the off season between Freshman and Sophomore years represented negative changes in body composition that should be addressed further. These results can help interdisciplinary athlete care teams optimize training programs in this population by understanding what changes are expected over multiple years. Normalizing these changes may also help the promotion of realistic body composition goals and the development of positive training and dietary habits.

Contextual factors influencing the characteristics of female football players

Women's football participation rates are projected to increase to 60 million worldwide by 2026, doubling the current participation. Growing investment and the increase in research in women's football has had a positive effect on the level of performance over the last 10 years. The present review aimed to examine the literature on the physical and physiological characteristics of female football players from 2010 to 2019 to reflect the recent changes in professionalism. Characteristics investigated include anthropometry, strength, speed, endurance, power, change of direction and repeated sprint ability. These characteristics are presented in relation to playing position, age and competition-level. Results revealed that goalkeepers (171 cm, 66 kg) and defenders (168 cm, 61 kg) were the tallest and had the greatest body mass, while attackers were the fastest players over 20 m (3.05 s) and 30 m (4.38 s) and midfielders had the highest endurance (55.4 mL∙kg^-1∙min^-1) (P<0.05). Characteristics tended to improve with age until full biological maturity around 17 to 18 years of age. Competition comparisons demonstrated international players have significantly greater speed, repeated sprint ability, power and endurance characteristics (P<0.05). By identifying influential factors, coaches may be able to optimize their training and physical assessment practices, to better expose players to the required stimulus to develop these characteristics considered crucial to improved performance.

Body Composition and Bone Mineral Density of Division 1 Collegiate Track and Field Athletes, a Consortium of College Athlete Research (C-CAR) Study

The purpose of the present study was to generate normative values for total and regional body composition in male and female Division 1 collegiate track and field athletes using dual X-ray absorptiometry. We also sought to examine body composition by event and sex. Data were used from the Consortium of College Athlete Research group. A total of 590 (male [M]/female [F] = 274/316) athletes had their height, weight, total and regional fat mass (FM), lean mass, and bone mineral density (BMD) measured. Athletes were classified into 1 of 7 categories: Jumps (M/F = 28/30); Long Distance (M/F = 104/110), Middle Distance (M/F = 27/24), Multievent (M/F = 11/9), Pole Vault (M/F = 21/27), Sprints (M/F = 54/96), and Throws (M/F = 29/20). Total and regional differences between events and sex were assessed by analysis of variance. Except for male and female throwers, all other track and field athletes' mean percent body fat (M: 10.3%-12.6%, F: 17.5%-21.6%) and visceral FM (<500 g) was low, but in a healthy range. As expected, throwers had significantly (p < 0.05) higher total and regional FM and lean mass than other events. In addition, male (1.55 ± 0.11 g/cm²) and female (1.40 ± 0.12 g/cm²) throwers had significantly greater BMD than all other events while male (1.25 ± 0.10 g/cm²) and female (1.16 ± 0.09 g/cm²) distance runners had significantly lower BMD than all other events. In conclusion, track athletes' body composition differed across events for both males and females. These measurements provide normative data on NCAA Division 1 male and female track and field athletes.

Seasonal Changes in Physiological Responses and Body Composition During a Competitive Season in Male and Female Elite Collegiate Ice Hockey Players

Delisle-Houde, P, Reid, RER, Insogna, JA, Chiarlitti, NA, and Andersen, RE. Seasonal changes in physiological responses and body composition during a competitive season in male and female elite collegiate ice hockey players. J Strength Cond Res 33(8): 2162-2169, 2019-Ice hockey continually overloads athletes with limited time for recovery, which may affect several physiological responses and alter body composition. The purpose of this study was to identify changes in physiological parameters and body composition profiles over the competitive season in elite collegiate ice hockey players. Forty-four players, 24 males (age = 22.7 ± 1.3 years, height = 1.82 ± 0.6 m, and body mass = 86.87 ± 6.44 kg) and 20 females (age = 19.9 ± 1.8 years, height = 1.66 ± 0.7 m, and body mass = 68.76 ± 5.91 kg) participated in 4-minute submaximal exercise tests and body composition assessments at pre-season, mid-season, and end-season. Changes in physiological parameters and body composition were analyzed using repeated-measures analysis of covariance controlling for age. Males' postexercise blood lactate concentration decreased (p ≤ 0.05) from pre- to mid-season (9.3 vs. 6.2 mmol·L) and increased (p ≤ 0.05) from mid- to end-season (6.2 vs. 8.0 mmol·L). Heart rate increased (p ≤ 0.05) after the third and fourth minute of the submaximal test in both sexes from pre- to end-season and from mid- to end-season. Males' body fat percentage decreased (p ≤ 0.05) from mid-season (17.4 vs. 16.1%), whereas increases were observed (p ≤ 0.05) in both sexes from mid- to end-season. This study produced evidence that male and female collegiate hockey athletes' physiological responses and body composition profiles change over the season. Sport scientists working with collegiate hockey teams, may need to revise annual training programs to attenuate reductions in fitness and hopefully prevent injuries.

Upper and lower thresholds of fat-free mass index in a large cohort of female collegiate athletes

Fat-free mass index (FFMI) is a height-adjusted metric of fat-free mass which has been suggested as a useful method of body composition assessment in athletic populations. The purpose of this study was to determine sport-specific FFMI values and the natural upper threshold of FFMI in female athletes. 372 female collegiate athletes (Mean±SD; 20.03±1.55 years, 167.55±7.50 cm, 69.46±13.04 kg, 24.18±5.48% bodyfat) underwent body composition assessment via dual-energy x-ray absorptiometry. FFMI was adjusted to height via linear regression and sport-specific reference values were determined. Between-sport differences were identified using one-way ANOVA with Tukey post-hoc tests. Average FFMI was 18.82±2.08 kg/m²; height-adjusted values were not significantly different (p<0.05) than unadjusted values. FFMI in rugby athletes (20.09±2.23 kg/m²) was found to be significantly higher (p<0.05) than in gymnastics (18.62±1.12 kg/m²), ice hockey (17.96±1.04 kg/m²), lacrosse (18.58±1.84 kg/m²), swim & dive (18.16±1.67 kg/m²), and volleyball (18.04±1.13 kg/m²). FFMI in cross country (16.56±1.14 kg/m²) and synchronized swimming (17.27±1.47 kg/m²) was significantly lower (p<0.05) than in Olympic weightlifting (19.69±1.98 kg/m²), wrestling (19.15±2.47 kg/m²), and rugby. The upper threshold for FFMI in female athletes (97.5^th percentile) was 23.90 kg/m². These results can be used to guide personnel decisions and assist with long-term body composition, training, and nutritional goals.

Same-Day Vs Consecutive-Day Precision Error of Dual-Energy X-Ray Absorptiometry for Interpreting Body Composition Change in Resistance-Trained Athletes

The application of dual-energy X-ray absorptiometry (DXA) in sport science settings is gaining popularity due to its ability to assess body composition. The International Society for Clinical Densitometry (ISCD) recommends application of the least significant change (LSC) to interpret meaningful and true change. This is calculated from same-day consecutive scans, thus accounting for technical error. However, this approach does not capture biological variation, which is pertinent when interpreting longitudinal measurements, and could be captured from consecutive-day scans. The aims of this study were to investigate the impact short-term biological variation has on LSC measures, and establish if there is a difference in precision based on gender in a resistance-trained population. Twenty-one resistance-trained athletes (age: 30.6 ± 8.2 yr; stature: 174.2 ± 7.2 cm; mass: 74.3 ± 11.6 kg) with at least 12 mo consistent resistance training experience, underwent 2 consecutive DXA scans on 1 d of testing, and a third scan the day before or after. ISCD-recommended techniques were used to calculate same-day and consecutive-day precision error and LSC values. There was high association between whole body (R² = 0.98-1.00) and regional measures (R² = 0.95-0.99) for same-day (R² = 0.98-1.00), and consecutive-day (R² = 0.95-0.98) measurements. The consecutive-day precision error, in comparison to same-day precision error, was significantly different (p < 0.05), and almost twice as large for fat mass (1261 g vs 660 g), and over 3 times as large for lean mass (2083 g vs 617 g), yet still remained within the ISCD minimum acceptable limits for DXA precision error. No whole body differences in precision error were observed based on gender. When tracking changes in body composition, the use of precision error and LSC values calculated from consecutive-day analysis is advocated, given this takes into account both technical error and biological variation, thus providing a more accurate indication of true and meaningful change.

Comparison of Body Composition Variables Across a Large Sample of National Collegiate Athletic Association Women Athletes From 6 Competitive Sports

Fields, JB, Metoyer, CJ, Casey, JC, Esco, MR, Jagim, AR, and Jones, MT. Comparison of body composition variables across a large sample of National Collegiate Athletic Association women athletes from 6 competitive sports. J Strength Cond Res 32(9): 2452-2457, 2018-Body composition (BC) plays a critical role in sport performance and athlete health. Body size and BC have been widely studied in men's sports, with reported changes observed over time. However, a paucity of current data exists in women athletes. The purpose of this descriptive study was to measure and compare BC data for collegiate women athletes from 6 competitive sports. A total of 524 athletes from 2 National Collegiate Athletic Association institutions participated: basketball (BB; n = 95), gymnastics (GYM; n = 42), lacrosse (LAX; n = 81), rowing (ROW; n = 57), soccer (SOC; n = 188), and volleyball (VB; n = 61). Body height (BH) and body mass (BM) were measured using a stadiometer and calibrated digital scale, respectively. Body fat percentage (BF%), fat mass (FM), and fat-free mass (FFM) were assessed using air displacement plethysmography. One-way analysis of variance was used to assess differences across sports. Least squares difference post hoc analyses were performed when a significant finding (p ≤ 0.05) was identified. ROW had the highest BF% (29.9 ± 6.1%) and BB the greatest FFM (57.2 ± 6.1 kg). GYM had the lowest BM (58.9 ± 5.3 kg), FM (11.6 ± 2.6 kg), and BH (158.73 ± 2.13 cm). LAX, SOC, and VB had similar BF%. Body height was greatest for BB and VB (177.92 ± 7.55 cm, 176.79 ± 7.36 cm, respectively). These data may assist in the establishment of descriptive values for use in goal setting and exercise programming. The current data demonstrate a trend toward increased body size and BC from previous research.

Jumping Performance is Preserved but Not Muscle Thickness in Collegiate Volleyball Players After a Taper

Bazyler, CD, Mizuguchi, S, Sole, CJ, Suchomel, TJ, Sato, K, Kavanaugh, AA, DeWeese, BH, and Stone, MH. Jumping performance is preserved but not muscle thickness in collegiate volleyball players after a taper. J Strength Cond Res 32(4): 1020-1028, 2018-The purpose of this study was to examine changes in muscle architecture and jumping performance in NCAA division I women's volleyball players throughout a competitive season and in preparation for conference championships. Ten women volleyball players were tested at preseason (T1), pretaper (T2), and post-taper (T3) on measures of vastus lateralis muscle thickness (MT), pennation angle (PA) and fascicle length (FL) using ultrasonography, and unloaded and loaded squat jump height (SJH) and peak power allometrically scaled to body mass (SJPPa) on a force platform. Rating of perceived exertion training load and strength training volume load were monitored weekly. Player's MT (p < 0.001, Glass's Δ = 2.8) and PA increased (p = 0.02, Δ = 3.9) after in-season training. However, MT decreased after the taper (p = 0.01, Δ = 0.6) but remained elevated above preseason values (p < 0.001, Δ = 1.7). There were no statistical changes in FL, SJH, or SJPPa. Large-to-very large negative relationships (r = -0.51 to -0.81) were observed between preseason relative maximal strength and changes in SJH and SJPPa with various loads over the season. These findings demonstrate that relatively low volumes of strength training and concurrent sport training during a tapering period are capable of preserving jumping performance, but not MT in women's volleyball players; however, jumping performance changes seem to be related to the player's strength level. Stronger players may benefit from an overreaching microcycle before the taper to preserve previously accrued muscular adaptations and jumping performance.

Seasonal and Longitudinal Changes in Body Composition by Sport-Position in NCAA Division I Basketball Athletes

The purpose of this study was to assess the body composition of male and female basketball athletes (n = 323) across season, year, and sport-position using air displacement plethysmography. An independent sample t-test assessed sport-position differences. An analysis of variance was used to assess within-subjects across season (pre-season, in-season, and off-season), and academic year (freshman, sophomore, and junior). For both men and women basketball (MBB, WBB) athletes, guards had the lowest body fat, fat mass, fat free mass, and body mass. No seasonal differences were observed in MBB, but following in-season play for WBB, a reduction of (p = 0.03) in fat free mass (FFM) was observed. Across years, MBB showed an increase in FFM from freshman to sophomore year, yet remained unchanged through junior year. For WBB across years, no differences occurred for body mass (BM), body fat (BF%), and fat mass (FM), yet FFM increased from sophomore to junior year (p = 0.009). Sport-position differences exist in MBB and WBB: Guards were found to be smaller and leaner than forwards. Due to the importance of body composition (BC) on athletic performance, along with seasonal and longitudinal shifts in BC, strength and conditioning practitioners should periodically assess athletes BC to ensure preservation of FFM. Training and nutrition programming can then be adjusted in response to changes in BC.

Interpretation of Dual-Energy X-Ray Absorptiometry-Derived Body Composition Change in Athletes: A Review and Recommendations for Best Practice

Dual-energy X-ray absorptiometry (DXA) is a medical imaging device which has become the method of choice for the measurement of body composition in athletes. The objectives of this review were to evaluate published longitudinal DXA body composition studies in athletic populations for interpretation of "meaningful" change, and to propose a best practice measurement protocol. An online search of PubMed and CINAHL via EBSCO Host and Web of Science enabled the identification of studies published until November 2016. Those that met the inclusion criteria were reviewed independently by 2 authors according to their methodological quality and interpretation of body composition change. Twenty-five studies published between 1996 and November 2016 were reviewed (male athletes: 13, female athletes: 3, mixed: 9) and sample sizes ranged from n = 1 to 212. The same number of eligible studies was published between 2013 and 2016, as over the 16 yr prior (between 1996 and 2012). Seven did not include precision error, and fewer than half provided athlete-specific precision error. There were shortfalls in the sample sizes on which precision estimates were based and inconsistencies in the level of pre-scan standardization, with some reporting full standardization protocols and others reporting only single (e.g., overnight fast) or no control measures. There is a need for standardized practice and reporting in athletic populations for the longitudinal measurement of body composition using DXA. Based on this review and those of others, plus the official position of the International Society for Clinical Densitometry, our recommendations and protocol are proposed as a guide to support best practice.

Evaluation of Seasonal Changes in Fitness, Anthropometrics, and Body Composition in Collegiate Division II Female Soccer Players

Peart, AN, Nicks, CR, Mangum, M, and Tyo, BM. Evaluation of seasonal changes in fitness, anthropometrics, and body composition in collegiate division II female soccer players. J Strength Cond Res 32(7): 2010-2017, 2018-The purpose of this study was to investigate anthropometrics, body composition, aerobic and anaerobic fitness of collegiate Division II female soccer players throughout a calendar year. Eighteen (20 ± 0.9 years) National Collegiate Athletics Association division II female soccer players from the same team participated in the study. Anthropometrics and body composition variables were assessed in addition to the counter movement jump (CMJ), Wingate Anaerobic Test (WAT), and peak oxygen uptake (V[Combining Dot Above]O2peak). Data were collected over 5 time points: end of competitive seasons (ECS1 and ECS2), beginning of off-season (BOS), end of off-season (EOS), and preseason (PS). Repeated-measures analysis of variance was conducted to compare test scores among all 5 data collection points. Where appropriate, Bonferroni post hoc tests were used to determine which points were significantly different. Hip circumference decreased significantly (p < 0.001) from EOS (98.47 ± 6.5 cm) to PS (94.46 ± 6.8 cm). Fat mass (12.73 ± 5.4 kg) was significantly different in ECS2 compared with BOS and EOS means (p ≤ 0.05) and percentage of body fat (%BF) (20.08 ± 5.44) significantly different in ECS2 compared with ECS1, BOS, and EOS means (p ≤ 0.05), whereas fat-free mass (FFM) was maintained from ECS1 to ECS2. Counter movement jump, WAT, and V[Combining Dot Above]O2peak performance did not significantly change from ECS1 to ECS2. Anthropometrics and body composition results are similar to previous studies measuring Division II to professional female soccer players. Counter movement jump results remained consistent and are comparable to results on Division I female soccer players. Coaches and researchers can use these data to help design and evaluate training programs throughout a calendar year.

Accuracy and Reliability of Assessing Lateral Compartmental Leg Composition Using Dual-Energy X-ray Absorptiometry

PURPOSE

This study aimed to investigate the accuracy and reliability of a novel dual-energy x-ray absorptiometry (DXA) scanning method in the frontal plane for total, fat, and lean mass quantification of the anterior and posterior upper leg compartments.

METHODS

Twenty-one (11 females; X¯age = 20.3 ± 1.3 yr) college athletes were assessed for total and regional body composition using DXA. The segmentation of anterior/posterior thigh compartments was measured with participants lying on their right and left sides and the scanned leg elevated with two foam pads. Custom regions of interest (ROIs) were created manually with enCore software for each scan using bony landmarks to quantify lean, fat, and total masses. Paired t-tests assessed this novel positioning method's accuracy against standard positioning. Intraclass correlation coefficients and coefficients of variation examined inter- and intrarater reliability for lateral scan measures of total, fat, and lean masses from manually created ROIs.

RESULTS

All mean ± SD differences between frontal and lateral DXA scans of right (R) and left (L) leg total mass (R: 8.42 ± 195.57 g; L: 19.47 ± 131.80 g), fat mass (R: 61.26 ± 215.66 g; L: -5.89 ± 239.97 g), and lean mass (R: -103.00 ± 302.54 g; L: -27.58 ± 288.14 g) were nonsignificant (P value range = 0.15-0.91). Intraclass correlation coefficients were high for all composition measures between and within raters, ranging from 0.983 to 0.999 and from 0.954 to 0.999, respectively, with low variation across measures (all coefficients of variation ≤ 5%).

CONCLUSION

The results of this study suggest that DXA measures using lateral subject positioning and custom ROIs to assess upper leg total, fat, and lean masses are accurate and reliable compared with total-body frontal subject positioning. Future studies are needed to determine the clinical usefulness of lateral view measures regarding prevention or rehabilitation of sports- or age-related injury.

Body Composition and Muscle Characteristics of Division I Track and Field Athletes

The purpose of this study was to evaluate event-specific body composition and muscle characteristics of track and field athletes and to assess body composition changes after 1 year. Sixty collegiate track and field athletes (mean ± SD; age = 19.2 ± 1.4 years, height = 174.6 ± 9.0 cm, and weight = 71.5 ± 12.5 kg) were stratified into 6 event groups. Total and regional body composition measurements were assessed using dual-energy x-ray absorptiometry. A panoramic scan of the vastus lateralis was taken with B-mode ultrasound to determine muscle cross-sectional area and echo intensity (EI). Body composition measurements were repeated a year later in a subset of returning athletes (n = 33). Throwers had significantly more absolute fat mass (FM; 21.6 ± 11.0 kg), total body mass (89.7 ± 17.4 kg), percent fat (23.6 ± 7.8), and trunk fat (9.4 ± 5.8 kg) than all other event groups (p ≤ 0.05). Throwers had the most absolute lean mass (LM; 64.2 ± 11.7 kg; p > 0.05), but relative to body mass had relatively less LM (0.72 ± 0.08 kg; p ≤ 0.05). Despite high FM, throwers had lower EI (63.4 ± 5.2 a.u). After 1 year, relative armLM increased slightly in all event groups (p ≤ 0.05). Evaluation of muscle characteristics in addition to total and regional body composition may be valuable for improving performance, injury prevention, and assessing health risks. With appropriate training, track and field athletes may be able to minimize losses in LM and gains in FM between seasons.

Effect of 8 weeks of pre-season training on body composition, physical fitness, anaerobic capacity, and isokinetic muscle strength in male and female collegiate taekwondo athletes

The purpose of the study was to determine the effect of 8 weeks pre-season training on body composition, physical fitness, anaerobic capacity, and isokinetic strength in collegiate taekwondo athletes. Thirty-four collegiate athletes (male: 22, female: 12) participated. Body composition, bone mineral density, physical fitness, anaerobic capacity, and isokinetic muscle strength were tested. After statistical analysis was performed the results indicated that there were significant decreases in body weight, percent body fat, and fat tissue after 8 weeks of pre-season training. Bone mineral density increased significantly only in males. There were significant improvements in the 50 m shuttle run and 20 m multistage endurance run in both males and females. The sit & reach test and standing long jump were not significantly changed after 8 weeks. Relative peak power and anaerobic capacity were significantly improved in males. Significant increases in angular velocity were observed for knee extension at both % BW 60°/sec and 180°/sec in both males and females. A significant increase in angular velocity was seen for right knee flexion at % BW 60°/sec for males, but it decreased at % BW 180°/sec for both males and females. In conclusion, this study suggests that 8 weeks of pre-season training has a positive effect on body composition, physical fitness, anaerobic capacity, isokinetic muscular strength, and endurance. Nevertheless, an exercise approach with the goal of increasing lean tissue, and improving power in knee flexors and flexibility of athletes, should be included in the training program.