Testing in Intermittent Sports-Importance for Training and Performance Optimization in Adult Athletes

ABSTRACT

Performance in intermittent sports relies on the interplay between multiple physiological systems determining the capacity to perform short explosive efforts as well as repeated intense actions with limited recovery over the course of an entire game. Testing should reflect these demands to allow for sport- and position-specific capacity analyses that eventually may translate into optimized training and improved performance. This may include individual load management and optimized training prescription, intensity targeting for specific positions or individual athletes, as well as benchmarking for monitoring of training progression and enhanced engagement of athletes. This review provides an overview of available tests in different exercise domains identified as relevant (from assessment of single explosive actions to intermittent endurance capacity), forming the basis for recommendations on how to compose a comprehensive yet feasible test battery that may be integrated into the seasonal competition and training plan. The test procedures should cover the performance spectrum of relevance for the individual athlete-also in team sports to account for positional differences. We emphasize the benefits of sport-specific tests, highlight parameters of importance for test standardization, and discuss how the applied test battery may be supplemented with secondary tests directed toward specific energy systems to allow for more in-depth analyses when required (e.g., in terms of an underperforming athlete). The synergy between testing and tracking of match performance (utilizing time-motion or global positioning systems) is highlighted, and although tracking cannot substitute for testing, combining the tools may provide a comprehensive overview of the physiological demands and performance during competition contextualized to the athletes' maximal exercise capacity.

Increased resting lactate levels and reduced carbohydrate intake cause νLa.max underestimation by reducing net lactate accumulation-A pilot study in young adults

Modulation of testing conditions such as resting lactate (Larest) levels or carbohydrate intake may affect the calculation of the maximal glycolytic rate (νLa.max). To evaluate the impact of elevated Larest as well as reduced and increased carbohydrate availability on νLa.max in running sprints (RST), twenty-one participants completed five 15-s RST tests on a running track under five different conditions: (I). baseline: Larest ≤1.5 mmol·L-1; (II). Lactate+: Larest ≥2.5 mmol·L-1; (III). CHO-: carbohydrate intake: ≤ 1 g·kg-1 BW d-1 for 3 days; (IV). CHO+: carbohydrate intake: ≥ 9 g·kg-1 BW d-1 for one day; and (V). acuteCHO: 500 mL glucose containing beverage consumed before RST. νLa.max was significantly reduced in lactate+ and CHO- conditions compared to the baseline RST, due to a reduction in the arithmetic mean delta (∆) between Lapeak and Larest lactate concentration (Lapeak, mmol · L-1). AcuteCHO led to an increase in Larest compared to baseline, CHO- and CHO+ with a high interindividual variability but did not significantly reduce νLa.max. Therefore, avoiding low carbohydrate nutrition before νLa.max testing, along with carefully adjusting Larest to below ≤1.5 mmol·L-1, is crucial to prevent the unintentional underestimation of νLa.max.

The effect of a 2-week ischaemic preconditioning intervention on anaerobic performance in male academy football players: a randomized, single-blinded, SHAM-Controlled study

Ischaemic preconditioning (IPC), brief periods of ischaemia immediately followed by reperfusion applied to a vascular bed, has emerged as a method to improve exercise performance. There is, however, a lack of research exploring repeated episodes of IPC on anaerobic performance. The aim of this study was to determine if a 2-week repeated IPC intervention could enhance anaerobic performance in male academy football players. Eight male academy football players completed two, 2-week intervention trials: six IPC episodes (4 × 5 min at 220 mmHg per episode), and six SHAM episodes (4 × 5 min at 20 mmHg per episode). Prior to and following each intervention trial, the participants completed assessments of anaerobic performance (Running Anaerobic Sprint Test [RAST]), and superficial femoral artery endothelial function (flow-mediated dilation [FMD]). IPC significantly enhanced peak and mean power output by 12% (p = 0.026) and 11% (p = 0.019) and significantly improved superficial femoral artery FMD (p = 0.049). The increase in endothelial function suggests that this may be a mechanism contributing to this enhancement of anaerobic performance. The present study supports the use of repeated IPC prior to matches and training sessions to enhance anaerobic performance.

Exercise testing for young athletes

With increasing competitiveness across the sporting landscape, there is a need for more research into monitoring and managing the young athlete, as the needs of a young athlete are vastly different to those of an older athlete who is already established in their respective sport. As the age of sports specialisation seems to decrease, exercise testing in the younger cohort of athletes is crucial for safety and long-term success. This article provides a comprehensive summary of available testing and monitoring methods that can be used to assist young athletes as they mature and attempt to excel in their chosen sport.

Comparison of usefulness of two tests measuring anaerobic performance of untrained and soccer-training girls U12

The study aimed to investigate the usefulness of the Running-based Anaerobic Sprint Test (RAST) in anaerobic performance estimation in trained and untrained girls U12, and the effect of an 8-week training period in female U12 soccer players on anaerobic performance. A comparative study of two structurally different anaerobic tests was performed to reach the goal. The study was designed as a non-randomized, controlled before-and-after trial. Fourteen female soccer players (FSP) and twelve untrained girls (UNT) participated in the study. During that time, all participants were subjected to school's physical education classes and the FSP additionally participated in regular soccer training. The anaerobic performance was evaluated twice, within 8-weeks period, using the traditional Wingate test (WAnT) and the RAST. A significant increase in the anaerobic performance of the FSP was noted (p < 0.05). In both tests peak, average, and relative power were significantly improved (p < 0.005). Nevertheless, strong, statistically significant (p < 0.05) correlation coefficients (0.50 < r < 0.70) were found for pre-training measurements between the WAnT and the RAST power parameters in absolute values. In UNT group significant improvement was found in peak, average and min power (p < 0.05) in the RAST. The improvement in anaerobic performance after training along with the strong correlation noted between the WAnT and the RAST power parameters prove the usefulness of the RAST in assessing anaerobic capacity in female youth athletes. Its simplicity encourages its use in monitoring anaerobic capacity in both trained and untrained girls.

The Acute Demands of Repeated-Sprint Training on Physiological, Neuromuscular, Perceptual and Performance Outcomes in Team Sport Athletes: A Systematic Review and Meta-analysis

BACKGROUND

Repeated-sprint training (RST) involves maximal-effort, short-duration sprints (≤ 10 s) interspersed with brief recovery periods (≤ 60 s). Knowledge about the acute demands of RST and the influence of programming variables has implications for training prescription.

OBJECTIVES

To investigate the physiological, neuromuscular, perceptual and performance demands of RST, while also examining the moderating effects of programming variables (sprint modality, number of repetitions per set, sprint repetition distance, inter-repetition rest modality and inter-repetition rest duration) on these outcomes.

METHODS

The databases Pubmed, SPORTDiscus, MEDLINE and Scopus were searched for original research articles investigating overground running RST in team sport athletes ≥ 16 years. Eligible data were analysed using multi-level mixed effects meta-analysis, with meta-regression performed on outcomes with ~ 50 samples (10 per moderator) to examine the influence of programming factors. Effects were evaluated based on coverage of their confidence (compatibility) limits (CL) against elected thresholds of practical importance.

RESULTS

From 908 data samples nested within 176 studies eligible for meta-analysis, the pooled effects (± 90% CL) of RST were as follows: average heart rate (HRavg) of 163 ± 9 bpm, peak heart rate (HRpeak) of 182 ± 3 bpm, average oxygen consumption of 42.4 ± 10.1 mL·kg-1·min-1, end-set blood lactate concentration (B[La]) of 10.7 ± 0.6 mmol·L-1, deciMax session ratings of perceived exertion (sRPE) of 6.5 ± 0.5 au, average sprint time (Savg) of 5.57 ± 0.26 s, best sprint time (Sbest) of 5.52 ± 0.27 s and percentage sprint decrement (Sdec) of 5.0 ± 0.3%. When compared with a reference protocol of 6 × 30 m straight-line sprints with 20 s passive inter-repetition rest, shuttle-based sprints were associated with a substantial increase in repetition time (Savg: 1.42 ± 0.11 s, Sbest: 1.55 ± 0.13 s), whereas the effect on sRPE was trivial (0.6 ± 0.9 au). Performing two more repetitions per set had a trivial effect on HRpeak (0.8 ± 1.0 bpm), B[La] (0.3 ± 0.2 mmol·L-1), sRPE (0.2 ± 0.2 au), Savg (0.01 ± 0.03) and Sdec (0.4; ± 0.2%). Sprinting 10 m further per repetition was associated with a substantial increase in B[La] (2.7; ± 0.7 mmol·L-1) and Sdec (1.7 ± 0.4%), whereas the effect on sRPE was trivial (0.7 ± 0.6). Resting for 10 s longer between repetitions was associated with a substantial reduction in B[La] (-1.1 ± 0.5 mmol·L-1), Savg (-0.09 ± 0.06 s) and Sdec (-1.4 ± 0.4%), while the effects on HRpeak (-0.7 ± 1.8 bpm) and sRPE (-0.5 ± 0.5 au) were trivial. All other moderating effects were compatible with both trivial and substantial effects [i.e. equal coverage of the confidence interval (CI) across a trivial and a substantial region in only one direction], or inconclusive (i.e. the CI spanned across substantial and trivial regions in both positive and negative directions).

CONCLUSIONS

The physiological, neuromuscular, perceptual and performance demands of RST are substantial, with some of these outcomes moderated by the manipulation of programming variables. To amplify physiological demands and performance decrement, longer sprint distances (> 30 m) and shorter, inter-repetition rest (≤ 20 s) are recommended. Alternatively, to mitigate fatigue and enhance acute sprint performance, shorter sprint distances (e.g. 15-25 m) with longer, passive inter-repetition rest (≥ 30 s) are recommended.

Physiological Responses and Fatigue during a Repeated Shuttle-Sprint Running Test in Adolescent Schoolchildren: A Comparison between Sexes and Fatigue Calculation Methods

We examined physiological responses and fatigue in adolescent boys and girls during a repeated shuttle-sprint running test in a school setting. We also compared three calculation methods to assess fatigue during repeated sprints: the fatigue index (FI), the percent sprint decrement (Sdec), and the slope of performance decrement (SlopeD). Twenty-six adolescent students (10 girls and 16 boys, age: 15.3 ± 0.5 y) performed six 30 m sprints with a 180° change of direction at 15 m, interspersed with 10 s of recovery. Blood lactate (BL), heart rate (HR) and countermovement jump performance (CMJ) were measured before and after the sprint test. Boys achieved significantly faster sprint times (11.7% to 14.8% faster than girls in all sprints, p < 0.01), and had higher post-test BL compared with girls (14.0 ± 2.9 vs. 11.3 ± 3.2 mmol/L; p = 0.02; d = 0.93). However, all fatigue indices (FI, Sdec and SlopeD) were similar in boys and girls (FI = 11.5 ± 5.0 vs. 11.5 ± 5.0; SlopeD = 10.6 ± 4.8 vs. 14.5 ± 5.1; Sdec = 5.6 ± 2.2 vs. 7.3 ± 2.2, in boys and girls, respectively, p > 0.05 for all) and were highly correlated with each other (r = 0.86 to 0.97, p < 0.01). CMJ was higher in boys (p < 0.05), but CMJ performance dropped similarly from pre- to post-test in boys and girls (13.7 ± 7.0%, p < 0.01). In conclusion, neuromuscular fatigue during and after repeated shuttle-sprint running is similar in boys and girls, despite the faster sprint times, higher CMJ and higher BL in boys. SlopeD may be used as an alternative index to quantify fatigue during repeated shuttle-sprinting, as it takes into account performance in all sprints and may provide an average sprint-by-sprint performance drop.

The Repeated Curve Sprint Test Appears to be an Appropriate Tool for Estimating Anaerobic Fitness in Young Trained Male Futsal Players

This study aimed to determine the magnitude of correlation between the repeated curve sprint test (RCST), the running-based anaerobic sprint test (RAST) and the Wingate anaerobic test (WAnT) in elite male futsal players to determine whether the field test can be a futsal-specific alternative assessment tool compared to the other tests. Fifteen trained futsal players (20±3 yrs) performed the RCST, RAST and WAnT in a crossover design over three weeks. Peak power (PP), average power (AP) and the fatigue index (FI) were obtained from the tests. Finger-prick blood-lactate measurements were performed before and after the tests, and heart rate loading was recorded. To assess the magnitude and direction of the relationship between variables the Pearson’s correlation coefficient (r) was calculated. In respect of AP, there was a significant correlation between the RCST and both the WAnT (r=0.63, p=0.012) and the RAST (r=0.67, p=0.006). In respect of PP, the RCST only correlated with the RAST (r=0.71, p=0.003). In respect of the FI, the RCST did not correlate with either the RAST or the WAnT (p>0.05). Post-test heart rate values in the RCST correlated with those in both the WAnT (r=0.88, p=0.001) and the RAST (r=0.77, p=0.001). Also, post-test blood-lactate levels in the RCST correlated with those in both the RAST (r=0.58, p=0.025) and the WAnT (r=0.54, p=0.039). In conclusion, the RCST can be a valid and practical field test for measuring anaerobic fitness in competitive futsal players.

Development and Validation of Prediction Formula of Wingate Test Peak Power From Force-Velocity Test in Male Soccer Players

Peak power of the Wingate anaerobic test (WAnT), either in W (Ppeak) or in W.kg^–1 (rPpeak), has been widely used to evaluate the performance of soccer players; however, its relationship with force–velocity (F-v) test (e.g., whether these tests can be used interchangeably) has received little scientific attention so far. The aim of this work was to develop and validate a prediction equation of Ppeak and rPpeak from F-v characteristics in male soccer players. Participants were 158 adult male soccer players (sport experience 11.4 ± 4.5 years, mean ± standard deviation, approximately five weekly training units, age 22.6 ± 3.9 years, body mass 74.8 ± 7.8 kg, and height 178.3 ± 7.8 cm) who performed both WAnT and F-v test. An experimental (EXP, n = 79) and a control group (CON, n = 79) were used for development and validation, respectively, of the prediction equation of Ppeak and rPpeak from F-v test. In EXP, Ppeak correlated very largely with body mass (r = 0.787), fat-free mass (r = 0.765), largely with maximal power of F-v test (P_max; r = 0.639), body mass index (r = 0.603), height (r = 0.558), moderately with theoretical maximal force (F₀; r = 0.481), percentage of body fat (r = 0.471), fat mass (r = 0.443, p < 0.001); rPpeak correlated with rPmax (largely; r = 0.596, p < 0.001), theoretical maximal velocity (v₀; moderately; r = 0.341, p = 0.002), F₀ (small magnitude; r = 0.280, p = 0.012), BF (r = −0.230, p = 0.042), and fat mass (r = −0.242, p = 0.032). Ppeak in EXP could be predicted using the formula “44.251 + 7.431 × body mass (kg) + 0.576 × P_max (W) – 19.512 × F₀” (R = 0.912, R² = 0.833, standard error of estimate (SEE) = 42.616), and rPpeak from “3.148 + 0.218 × rPmax (W.kg^–1) + v0 (rpm)” (R = 0.765, R² = 0.585, SEE = 0.514). Applying these formulas in CON, no bias was observed between the actual and the predicted Ppeak (mean difference 2.5 ± 49.8 W; 95% CI, −8.7, 13.6; p = 0.661) and rPpeak (mean difference 0.05 ± 0.71 W.kg^–1; 95% CI, −0.11, 0.21, p = 0.525). These findings provided indirect estimates of Ppeak of the WAnT, especially useful in periods when this test should not be applied considering the fatigue it causes; in this context, the F-v test can be considered as an alternative of exercise testing for estimating the average Ppeak of a group of soccer players rather than for predicting individual scores when the interindividual variation of performance is small.

Repeated Sprint Ability in Elite Basketball Players: The Effects of 10 × 30 m Vs. 20 × 15 m Exercise Protocols on Physiological Variables and Sprint Performance

Team sports players are required to perform repeated bouts of short-term high-intensity actions during the games. The present study aimed to examine the effects of a novel repeated sprint ability protocol (20×15 m) and compare it with the impact of a more traditional repeated sprint ability protocol (10×30 m). Twelve male elite Lithuanian basketball players (age 21.0 ± 2.0 y, body height 1.90 ± 0,07 m, body mass 86.2 ± 5.8 kg and training experience 12.0 ± 1.9 y) competing in the Lithuanian National Basketball Championship participated in this study. Participants completed three bouts of each repeated sprint protocol interspersed with 5 minutes of recovery. Results showed that the 20×15 m protocol caused a significant decrease in total sprint time (most likely; mean changes (%) with ± 90% of confidence limits, -9.4%; ± 0.7%) and a large decrease in blood lactate (most likely, -39.2%; ±12.8%) compared to the 10×30 m protocol. Despite small differences, the fatigue index presented a similar trend (possibly decrease, -23.7%; ± 38.8%). The exercise heart rate showed a very similar trend with trivial differences between the two protocols. The 20×15 m protocol presented a lower heart rate during recovery with small magnitude. Overall, the present study showed that the 20×15 m protocol seemed to be more representative of the specific basketball demands. Coaches should be aware that RSA training during the in-season may be an adequate stimulus to improve high-intensity runs and muscle power in high-level players.

Warm-up durations in a hot-dry climate affect thermoregulation, mean power-output and fatigue, but not peak power in specific soccer repeated-sprint ability

Background

This study addressed the lack of data on the effect of warm-up (WU) duration in hot-dry climate (~ 30 °C; ~ 18% RH), on thermoregulation, muscular power-output, and fatigue after specific soccer repeated-sprint test (RSA).

Methods

Eleven amateur soccer players participated in a cross-over randomized study and they underwent the Bangsbo repeated-sprint test, after three WU durations (i.e. WU10, WU15 and WU20 min) at 70% of MAV, and on different days. Peak power (PP), mean power (MP) and the fatigue index (FI) were recorded and analyzed. Likewise, heart rate (HR), tympanic temperature (T_tym), mean body temperature (MBT) and rating of perceived exertion (RPE) were recorded during each session.

Results

The repeated measure ANOVA showed that MP improved after WU15 in comparison to WU10 and WU20 (p = 0.04 and p = 0.001; respectively). Nonetheless, no significant effect on PP was recorded after all WU durations. FI during RSA increased after WU20 in comparison to WU15 and WU10 (p < 0.001 and p = 0.003; respectively). Higher RPE values (p < 0.001) were recorded after WU15 and WU20 in comparison to WU10 duration. The two-way ANOVA showed higher ΔT_tym and ΔMBT values after WU15 and WU20 compared to WU10 (p = 0.039 and p < 0.001for T_tym; p = 0.005 and p < 0.001 for MBT, respectively).

Conclusions

The WU15 at 70% of MAV better assists mean power-output during soccer RSA in hot-dry (~ 30 °C; 18% RH) climate, but not peak power. Reducing WU duration up to 10 min seems to be insufficient to induce beneficial physiological changes necessary for optimizing repeated-sprint performance, while its extension up to 20 min remains detrimental for muscular power and induces higher fatigue.

Fatigue index and anaerobic power obtained in different surfaces types

Abstract Due to the high intensity of competitive sports, the anaerobic power is a very important physical capacity for most sports. However, the diverse surfaces were these sports may interfere in the performance of this capacity. In running-based sports, the Running Anaerobic Sprint Test – RAST is largely used to evaluate anaerobic power. Considering the specificity of each sport, it is suggested to apply this test on the surface that it is played. Thus, the aim of the present study is to analyze the performance of RAST on different surfaces. The sample was composed by 10 subjects, mean age 20.2 ± 0.9 years old, mean height 1.8 ± 0.1 meters, mean body weight 77.4 ± 15.9 kg, and practice time of 6.0 ± 2.0 years. RAST was conducted on three different surfaces (hard, grass and sand). The maximum and minimum power and the fatigue index were compared between the surfaces. The results indicate that maximum and minimum power were lower in sand when compared to grass and hard surfaces. However, the fatigue index did not change. So, we observed that the surface is an important factor in RAST performance.

Repeated-Sprint Ability in Division I Collegiate Male Soccer Players: Positional Differences and Relationships With Performance Tests

Lockie, RG, Moreno, MR, Orjalo, AJ, Stage, AA, Liu, TM, Birmingham-Babauta, SA, Hurley, JM, Torne, IA, Beiley, MD, Risso, FG, Davis, DL, Lazar, A, Stokes, JJ, and Giuliano, DV. Repeated-sprint ability in Division I collegiate male soccer players: positional differences and relationships with performance tests. J Strength Cond Res 33(5): 1362-1370, 2019-Repeated-sprint ability (RSA) in essential for soccer. Important considerations when assessing RSA is whether there are differences between positions (defenders, midfielders, and forwards), and what physiological characteristics may contribute to RSA. This has not been assessed in collegiate male players. Eighteen Division I male field players from one school performed several performance tests. The RSA test involved 7 × 30-m sprints completed on 20-second cycles. Measurements included total time (TT), and performance decrement (percent change in time from the first to last sprint; PD). Subjects also completed tests of lower-body power (vertical [VJ] and standing broad jump [SBJ]); linear (30-m sprint; 0-5 m, 0-10 m, 0-30 m intervals) and change-of-direction (505) speed; and soccer-specific endurance (Yo-Yo Intermittent Recovery Test Level 2; YYIRT2). A one-way analysis of variance (p < 0.05) determined between-position differences, and effect sizes were calculated. Pearson's correlations (p < 0.05) calculated relationships between RSA TT and PD with the other tests. There were no significant between-position differences for any test. There were large effects for the faster right-leg 505 and greater YYIRT2 distance for midfielders compared with defenders and forwards. Nonetheless, no between-position differences in RSA TT and PD were documented. There were relationships between RSA TT and the VJ (r = -0.59), SBJ (r = -0.61), 0-10 m (r = 0.64) and 0-30-m (r = 0.83) sprint intervals. There were no significant correlations for RSA PD. Male field players from one collegiate soccer team can demonstrate similar RSA across different positions. Greater lower-body power and sprinting speed could augment RSA.

Racial differences in hemoglobin and plasma volume variation: implications for muscle performance and recovery

Objective: To examine the effect of race differences on sprint performance, Hemoglobin (Hb), Hematocrit (Ht) and plasma volume (PV) variation in response to repeated sprint exercise. Design: Thirty-six healthy, moderately trained men and women (20.8 ± 0.2 year-old) volunteered to participate in this study. They were allocated to one of the four groups according to their gender and race: Black men's group (BM, n = 9), White men's group (WM, n = 9), Black women's group (BW, n = 9) and White women's group (WW, n = 9). All participants performed the running-based anaerobic sprint test (RAST), which consists of six 35-m sprints with 10 s of recovery in-between. Six venous blood samples were collected to determine Hb, Ht and PV levels at rest, after warm-up, immediately post- and at 5, 15 and 30 min post-RAST. Blood lactate is also sampled during the 3rd minutes of recovery. Results: The best running time was significantly shorter (P = .002) in BW compared to WW. We have observed significantly higher Hb (P = .010) and Ht (P = .004) levels in BW compared to WW during the 5th minute of recovery. During RAST, the PV decreased significantly (P = .007) in WM only. Black groups had lower (P < .05) lactate levels compared to the white subjects. During recovery, PV increase was significantly (P = .003) higher in WW compared to BW during the 5th minute of recovery. Conclusion: This study demonstrated that sprint and repeated sprint performances were different between white and black women. Differences in anaerobic performance between the groups were associated with racial differences in lactate levels and blood count among women's group during recovery time. Hence, it is important to take into account this race-related difference in hematological parameters in responses to intense efforts.

Performance and Metabolic Demand of a New Repeated-Sprint Ability Test in Basketball Players: Does the Number of Changes of Direction Matter?

Zagatto, AM, Ardigò, LP, Barbieri, FA, Milioni, F, Dello Iacono, A, Camargo, BHF, and Padulo, J. Performance and metabolic demand of a new repeated-sprint ability test in basketball players: does the number of changes of direction matter? J Strength Cond Res 31(9): 2438-2446, 2017-This study compared 2 repeated-sprint ability (RSA) tests in basketball players. Both tests included 10 × 30-m sprints, with the difference that the previously validated test (RSA2COD) featured 2 changes of direction (COD) per sprint, whereas the experimental test (RSA5COD) featured 5 CODs per sprint. Test performances and metabolic demands were specifically assessed in 20 basketball players. First, RSA5COD test-retest reliability was investigated. Then, RSA2COD, RSA5COD sprint times, peak speeds, oxygen uptake (V[Combining Dot Above]O2) and posttest blood lactate concentration [La] were measured. The RSA5COD results showed to be reliable. RSA2COD performance resulted better than the RSA5COD version (p < 0.01), with shorter sprint times and higher peak speeds. Over sprints, the tests did not differ from each other in terms of V[Combining Dot Above]O2 (p > 0.05). Over whole bout, the RSA2COD was more demanding than the RSA5COD, considering overall metabolic power requirement (i.e., VO2-driven + [La]-driven components). Given that RSA5COD (a) mimics real game-play as sprint distance and action change frequency/direction and (b) has the same metabolic expenditure per task completion as metabolic cost, RSA5COD is a valuable option for players and coaches for training basketball-specific agility and assessing bioenergetic demands.

Predictors of high-intensity running capacity in collegiate women during a soccer game

The purpose of this investigation was to determine which physiological assessments best predicted high-intensity running (HIR) performance during a women's collegiate soccer game. A secondary purpose was to examine the relationships among physiological performance measures including muscle architecture on soccer performance (distance covered, HIR, and sprints during the game) during a competitive collegiate women's soccer game. Ten National Collegiate Athletic Association (NCAA) Division I women soccer players performed physiological assessments within a 2-week period before a competitive regulation soccer game performed during the spring season. Testing consisted of height, body mass, ultrasound measurement of dominant (DOMleg), and nondominant leg (NDOMleg) vastus lateralis for muscle thickness (MT) and pennation angle (PA), VO2max, running economy, and Wingate anaerobic test (WAnT) for peak power (PP), mean power (MP), and fatigue rate (FR). During the game, distance run, HIR, and sprints were measured using a 10-Hz global positioning system. Stepwise regression revealed that VO2max, dominant leg thickness, and dominant leg PA were the strongest predictors of HIR distance during the game (R = 0.989, SEE = 115.5 m, p = 0.001). V[Combining Dot Above]O2max was significantly correlated with total distance run (r = 0.831; p = 0.003), HIR (r = 0.755; p = 0.012), WAnTPP (r = -0.737; p = 0.015), WAnTPP·kg (r = -0.706; p = 0.022), and WAnTFR (r = -0.713; p = 0.021). DOMlegMT was significantly correlated with WAnTFR (r = 0.893; p = 0.001). DOMlegPA was significantly correlated with WAnTFR (r = 0.740; p = 0.023). The NDOMlegPA was significantly correlated to peak running velocity (r = 0.781; p = 0.013) and WAnT MP·kg (r = 0.801; p = 0.01). Results of this study indicate that V[Combining Dot Above]O2max and muscle architecture are important characteristics of NCAA Division I women soccer players and may predict HIR distance during a competitive contest.