Retrospective and Contemporary Predictors of National Collegiate Athletic Association Division I Cross-Country Performance Are Sex Specific.

ABSTRACT: Carder, MJ, Scudamore, EM, Savanna, KN, Pribyslavska, V, Bowling, LR, and O'Neal, EK. Retrospective and contemporary predictors of National Collegiate Athletic Association Division I cross-country performance are sex specific. J Strength Cond Res 37(11): 2267-2272, 2023-The purpose of this study was to identify National Collegiate Athletic Association (NCAA) Division I cross-country (XC) performance potential using laboratory-based and field-based parameters and retrospective high school (HS) personal best (PB) data at various distances of current collegiate XC runners. Fifteen female and 17 male NCAA XC runners provided their PB for 5-km (women) and 8-km (men) distances from the previous season. Bivariate correlation and stepwise and hierarchical regression modeling were used to predict XC performance. Single squat jump height and multijump reactive strength index displayed r < 0.27 for both sexes, suggesting lower-body power is a poor predictor of XC performance or masked by other factors of greater importance. Triceps skinfold thickness approached significance (r = 0.43; p = 0.09) for men but was unrelated to women's performance (r = -0.05; p = 0.86). HS XC PB neared significance (r = 0.55, p = 0.054), but no other single or combination of variables reached significance for female runners. Aerobic capacity displayed a moderate to strong relationship (r = 0.65) for male runners. High school 3,200-m PB for men produced a robust prediction capacity (r = 0.85; p = 0.005, SEE = ± 0.65 minutes), and predicted 8-km PB within 30 seconds for approximately two-thirds of runners. These outcomes suggest when recruiting HS or transfer athletes, male and female XC runners should not be recruited on the same factors. Women's XC PB is more difficult to predict, but skinfold thickness was statistically the least valuable predictor of all factors.

Effects of foam rolling for delayed onset muscle soreness on loaded military task performance and perceived recovery.

OBJECTIVE: The purpose of this investigation was to evaluate the effects of foam rolling (FR) and passive recovery (PR) on symptoms of delayed-onset muscle soreness (DOMS) and military-specific performance. METHODS: Twenty men and women (age: 23.6 ± 4.1 years, height: 176.4 ± 5.6 cm, and body mass: 84.7 ± 13.4 kg) completed a DOMS-inducing exercise protocol (DIP), followed by FR or PR. Four loaded military tasks (LMT) were performed 24 h later. Rating of perceived exertion (RPE) was measured during DIP and after each LMT. Rating of muscle pain (RMP) was measured prior to the LMTs and after the recovery protocols. A repeated measure analysis of variance and partial eta squared were used to compare LMT performance across baseline, FR and PR sessions. Friedman tests compared perceptual variables across baseline, FR, and PR. Wilcoxon matched-pairs signed-ranks test evaluated RPE during DIP, post-DIP, and post-recovery RMP between FR and PR. RESULTS: LMT performance times were significantly faster after FR compared to PR (stair climb: p = .038, cover position sprint: p = .011, simulated ammunition can carry: p = .003, Shuttle Run: p = .034). RPE measured during LMTs was similar across all data points. Post-recovery RMP for FR (3.0 (2.3, 4.0)) and PR (4.0 (3.0, 6.0)) were not significantly different. CONCLUSION: FR reduced the impact of DOMS on three loaded tactical performance tasks without significant reduction in perceived soreness.

A Comparative Analysis of Army Body Composition Standards for Women.

The aim of this study was to compare body fat percentage (BF%) of women measured using the U.S. Army standard body composition assessment (ABC) and two common laboratory measures of body composition to evaluate the efficacy of ABC within this population. The BF% of 27 women (21.5 ± 1.8 years) was assessed using the 7-site skinfold, air plethysmography, and ABC measurements. The initial physical fitness test (IPFT) was used to determine if participants met the criteria required for admittance into basic combat training. A repeated measures ANOVA identified differences in BF% between the three assessment methods, (F (2, 52) = 22.83, p < .001, η2 p = .47). Pairwise comparisons revealed that mean BF% obtained using the ABC (29.3 ± 7.7 %) was significantly higher (p = .042) than BF% measured using air plethysmography (26.9 ± 8.4 %). ABC and air plethysmography measured BF% was significantly higher (both p < .001) than BF% obtained from skinfold assessment (22.2 ± 5.9 %). Of the 27 total participants, 4 (14.8%) passed IPFT but failed to meet the Army body composition standards using the ABC method. The primary findings of this study suggest that the overestimation of BF% by the ABC method could lead to an unnecessary delay in enlistment for women approaching the upper threshold of the Army's acceptable body composition standards. Alternative methods of assessing body composition in this population should be explored. However, skinfold assessment does not appear to be a suitable alternative to the ABC.

Urine Specific Gravity as a Practical Marker for Identifying Suboptimal Fluid Intake of Runners ∼12-hr Postexercise.

The legitimacy of urine specific gravity (USG) as a stand-alone measure to detect hydration status has recently been challenged. As an alternative to hydration status, the purpose of this study was to determine the diagnostic capability of using the traditional USG marker of >1.020 to detect insufficient recovery fluid consumption with consideration for moderate versus high sweat losses (2.00-2.99 or >3% body mass, respectively). Adequate recovery fluid intake was operationally defined as ≥100% beverage fluid intake plus food water from one or two meals and a snack. Runners (n = 59) provided 132 samples from five previous investigations in which USG was assessed 10-14 hr after 60-90 min runs in temperate-to-hot environments. Samples were collected after a meal (n = 58) and after waking (n = 74). When sweat losses exceeded 3% body mass (n = 60), the relationship between fluid replacement percentage and USG increased from r = -.55 to -.70. Correct diagnostic decision improved from 66.6 to 83.3%, and receiver operating characteristic area under the curve increased the diagnostic accuracy score from 0.76 to approaching excellent (0.86). Artifacts of significant prerun hyperhydration (eight of 15 samples has USG <1.005) may explain false positive diagnoses, while almost all (84%) cases of false positives were found when sweat losses were <3.0% of body mass. Evidence from this study suggests that euhydrated runners experiencing significant sweat losses who fail to reach adequate recovery fluid intake levels can be identified by USG irrespective of acute meal and fluid intake ∼12-hr postrun.

Impact of EPOC adjustment on estimation of energy expenditure using activity monitors.

PURPOSE: To examine the accuracy of activity monitors in estimating energy expenditure (EE) during activities of varying mode and intensity and to evaluate the impact of including energy expended during recovery from activity (EPOC) on the EE estimate. EE estimates obtained from the Fitbit Surge (FBS), Garmin Vívofit (GV) and SenseWear Armband Mini (SWA) were compared to criterion EE with and without EPOC adjustments during moderate- and vigorous-intensity treadmill and cycling activities. METHODS: Participants (N = 34; 23 males) completed counterbalanced treadmill or cycling conditions, comprised of a resting metabolic rate measurement, 10-min bouts of moderate- and vigorous-intensity activity and an EPOC measurement. Participants simultaneously wore the three activity monitors and a portable metabolic analyser. RESULTS: The FBS provided lowest percent error (PE) during treadmill walking (4.4%) and the GV during moderate (6.4%) and vigorous (-0.1%) cycling bouts. EPOC-adjusted PE was higher than non-EPOC PE across all monitors and activities. Mean absolute error rate (MAPE), indicating overall measurement error, was the smallest for the FBS (14.1%) during moderate treadmill walking and the largest for the SWA (53.5%) for vigorous intensity cycling. Only the FBS had comparable non-EPOC (14.6%) and EPOC-adjusted (17.6%) MAPE during treadmill walking. CONCLUSION: The activity monitors tended to underestimate EE during moderate and vigorous treadmill and cycling activities. The EE estimates from the activity monitors did not account for the energy cost met by anaerobic means during activity, as suggested by the higher EPOC-adjusted EE error rates.

Fluid Retention and Utility of Practical Hydration Markers to Detect Three Levels of Recovery Fluid Intake in Male Runners.

Runners are unlikely to consume fluid during training bouts increasing the importance of recovery rehydration efforts. This study assessed urine specific gravity (USG) responses following runs in the heat with different recovery fluid intake volumes. Thirteen male runners completed 3 evening running sessions resulting in approximately 2,200 ± 300 ml of sweat loss (3.1 ± 0.4% body mass) followed by a standardized dinner and breakfast. Beverage fluid intake (pre/postbreakfast) equaled 1,565/2,093 ml (low; L), 2,065/2,593 ml (moderate; M) and 2,565/3,356 mL (high; H). Voids were collected in separate containers. Increased urine output resulted in no differences (p > .05) in absolute mean fluid retention for waking or first postbreakfast voids. Night void averages excluding the first void postrun (1.025 ± 0.008; 1.013 ± 0.008; 1.006 ± 0.003), first morning (1.024 ± 0.004; 1.015 ± 0.005; 1.014 ± 0.005), and postbreakfast (1.022 ± 0.007; 1.014 ± 0.007; 1.008 ± 0.003) USG were higher (p < .05) for L versus M and H respectively and more clearly differentiated fluid intake volume between L and M than color or thirst sensation. Waking (r = -0.66) and postbreakfast (r = -0.71) USG were both significantly correlated (p < .001) with fluid replacement percentage, but not absolute fluid retention. Fluid intake M was reported as most similar to normal consumption (5.6 ± 1.0 on 0-10 scale) after breakfast and equaled 122 ± 16% of sweat losses. Retention data suggests consumption above this level is not warranted or actually practiced by most runners drinking ad libitum, but that periodic prerun USG assessment may be useful for coaches to detect runners that habitually consume low levels of fluids between training bouts in warm seasons.

Influence of carbohydrate mouth rinsing on running and jumping performance during early morning soccer scrimmaging.

Carbohydrate mouth rinse (CMR) is a novel method proposed to enhance endurance performance lasting ≤ 60 min. The current study examined the influence of CMR on anaerobic performance tasks in 11 collegiate female soccer players after an overnight fast. Athletes completed two experimental sessions, during which carbohydrate (CHO; 6% maltodextrin) or taste- and colour-matched placebo (PLA) mouth-rinse solutions were administered in a counterbalanced, double-blinded design. Three rounds of a 5-min scrimmage bout and series of performance tests including a single countermovement vertical jump (1VJ), a set of four consecutive vertical jumps, a 72-m shuttle run (SR72) and 18-m sprint comprised each trial. Thirst sensation (TS), session TS, ratings of perceived exertion (RPE) and session RPE were assessed as secondary outcomes. The first SR72 approached significance (p = 0.069), but no significant between-trials differences were observed for any of the mean performance tasks. The highest 1VJ scores did not differ for the first (CHO = 47.3 ± 3.4, PLA = 47.7 ± 3.5 cm; p = 0.43), second (CHO = 48.0 ± 4.1, PLA = 47.9 ± 3.5 cm; p = 0.82) or third bout (CHO = 47.4 ± 3.9, PLA = 48.1 ± 3.9 cm; p = 0.26). TS approached significance (p = 0.053) during the first bout. No significant differences (p > 0.05) were found for any of the perceptual variables. Current results fail to support ergogenic influence of CMR on anaerobic performance tasks in collegiate female athletes.