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Seihati A. Shiroma, Ursula F. Julio and Emerson Franchini

Purpose: To evaluate criterion validity, reliability, and usefulness of a test to measure maximal aerobic power using judo-specific movements (uchi-komi test [UKtest]). Methods: A total of 12 judokas performed 5 graded exercise tests (GETs) in 4 sessions. In sessions 1 and 2, upper-body (UBtest), lower-body (LBtest), and familiarization UKtest were performed. GETs were randomly performed and separated by at least 48 h. In sessions 3 and 4, test and retest UKtest were performed (7 d apart). For all GETs, peak oxygen consumption (V˙O2peak), maximal heart rate (HRmax), peak blood lactate concentration [Lapeak], maximal aerobic intensity, and rating of perceived exertion (RPE) were determined. Another group of 12 judokas performed the UKtest and 1 confirmation test (20 min after the UKtest) at 105% of maximal aerobic speed until exhaustion to confirm whether maximal responses were achieved. Results: V˙O2peak did not differ (P > .05) between UKtest (46.04 [5.34] mL·kg−1·min−1) and LBtest (44.78 [5.98] mL·kg−1·min−1), but it was higher (P < .05) than UBtest (37.03 [7.16] mL·kg−1·min−1). Total duration (551 [60] s) and [Lapeak] (7.10 [1.76] mmol·L−1) in the UKtest were different (P < .05) from UBtest (416 [47] s, 9.93 [2.15] mmol·L−1, respectively) and LBtest (433 [54] s, 10.29 [2.23] mmol·L−1, respectively). Very large relationships between V˙O2peak in UKtest with UBtest (r = .78; P = .003) and LBtest (r = .87; P < .001) were found. Maximal values were achieved for the UKtest V˙O2peak, HRmax, [Lapeak], RPE, and maximal aerobic speed, with no difference between test and retest (P > .05). In addition, very large intraclass correlation coefficients (ICC) for V˙O2peak (ICC = .86), HRmax (ICC = .90), and maximal aerobic speed (ICC = .81) were found. Conclusion: The UKtest can be considered a valid, reliable, and useful test to measure maximal aerobic power using judo-specific movements.

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David Giles, Joel B. Chidley, Nicola Taylor, Ollie Torr, Josh Hadley, Tom Randall and Simon Fryer

Purpose: To determine if the mathematical model used for the estimation of critical force (CF) and the energy store component W′ are applicable to intermittent isometric muscle actions of the finger flexors of rock climbers, using a multisession test. As a secondary aim, the agreement of estimates of CF and W′ from a single-session test was also determined. The CF was defined as the slope coefficient, and W′ was the intercept of the linear relationship between total “isometric work” (W lim) and time to exhaustion (T lim). Methods: Subjects performed 3 (separated by either 20 min or >24 h) tests to failure using intermittent isometric finger-flexor contractions at 45%, 60%, and 80% of their maximum voluntary contraction. Results: Force plotted against T lim displayed a hyperbolic relationship; correlation coefficients of the parameter estimates from the work–time CF model were consistently very high (R 2 > .94). Climbers’ mean CF was 425.7 (82.8) N (41.0% [6.2%] maximum voluntary contraction) and W′ was 30,882 (11,820) N·s. Good agreement was found between the single-session and multisession protocol for CF (intraclass correlation coefficient [ICC3,1] = .900; 95% confidence interval, .616–.979), but not for W′ (ICC3,1 = .768; 95% confidence interval, .190–.949). Conclusions: The results demonstrated the sensitivity of a simple test for the determination of CF and W′, using equipment readily available in most climbing gyms. Although further work is still necessary, the test of CF described is of value for understanding exercise tolerance and to determine optimal training prescription to monitor improvements in the performance of the finger flexors.

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Peter Ibbott, Nick Ball, Marijke Welvaert and Kevin G. Thompson

Purpose: To assess pacing strategies using prescribed and self-selected interset rest periods and their influence on performance in strength-trained athletes. Methods: A total of 16 strength-trained male athletes completed 3 randomized heavy strength-training sessions (5 sets and 5 repetitions) with different interset rest periods. The interset rest periods were 3 min (3MIN), 5 min (5MIN), and self-selected (SS). Mechanical (power, velocity, work, and displacement), surface electromyography (sEMG), and subjective (rating of perceived exertion) and readiness-to-lift data were recorded for each set. Results: SS-condition interset rest periods increased from sets 1 to 4 (from 207.52 to 277.71 s; P = .01). No differences in mechanical performance were shown between the different interset rest-period conditions. Power output (210 W; 8.03%) and velocity (0.03 m·s−1; 6.73%) decreased as sets progressed for all conditions (P  < .001) from set 1 to set 5. No differences in sEMG activity between conditions were shown; however, vastus medialis sEMG decreased as the sets progressed for each condition (1.75%; P = .005). All conditions showed increases in rating of perceived exertion as sets progressed (set 1 = 6.1, set 5 = 7.9; P < .001). Participants reported greater readiness to lift in the 5MIN condition (7.81) than in the 3MIN (7.09) and SS (7.20) conditions (P < .001). Conclusions: Self-selecting interset rest periods does not significantly change performance compared with 3MIN and 5MIN conditions. Given the opportunity, athletes will vary their interset rest periods to complete multiple sets of heavy strength training. Self-selection of interset rest periods may be a feasible alternative to prescribed interset rest periods.

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Nick Dobbin, Jamie Highton, Samantha Louise Moss and Craig Twist

Purpose: To investigate the factors affecting the anthropometric and physical characteristics of elite academy rugby league players. Methods: One hundred ninety-seven elite academy rugby league players (age = 17.3 [1.0] y) from 5 Super League clubs completed measures of anthropometric and physical characteristics during a competitive season. The interaction between and influence of contextual factors on characteristics was assessed using linear mixed modeling. Results: All physical characteristics improved during preseason and continued to improve until midseason, whereafter 10-m sprint (η 2 = .20 cf .25), countermovement jump (CMJ) (η 2 = .28 cf .30), and prone Yo-Yo Intermittent Recovery (Yo-Yo IR) test (η 2 = .22 cf .54) performance declined. Second (η 2 = .17) and third (η 2 = .16) -year players were heavier than first-years, whereas third-years had slower 10-m sprint times (η 2 = .22). Large positional variability was observed for body mass, 20-m sprint time, medicine-ball throw, CMJ, and prone Yo-Yo IR1. Compared with bottom-ranked teams, top-ranked teams demonstrated superior 20-m (η 2 = −.22) and prone Yo-Yo IR1 (η 2 = .26) performance, whereas middle-ranked teams reported higher CMJ height (η 2 = .26) and prone Yo-Yo IR1 distance (η 2 = .20) but slower 20-m sprint times (η 2 = .20). Conclusion: These findings offer practitioners who design training programs for academy rugby league players insight into the relationships between anthropometric and physical characteristics and how they are influenced by playing year, league ranking, position, and season phase.

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Cesar Gallo-Salazar, Juan Del Coso, David Sanz-Rivas and Jaime Fernandez-Fernandez

Purpose: To determine whether the game activity and physiological responses of young tennis players differed depending on the session of play (eg, morning [MOR] vs afternoon [AFT]) and the final match outcome (eg, winners vs losers) during a simulated competition with 2 matches on the same day. Methods: A total of 12 well-trained male tennis players (age 14.5 [0.8] y) took part in a simulated competition of two 3-set matches separated by 3 h. All the matches were video recorded, and the participants were monitored using 10-Hz global positioning system units including a heart-rate monitor. Effect-size (ES) statistics were used to investigate the magnitudes of the differences. Results: During the AFT matches, in absolute terms, players covered longer total distance (ES = moderate) and ran more distance between 0 and ≤4 m·s−1 (ES = small to large) than in MOR matches. Total duration was also longer (ES = large) in the AFT, where the rest time between rallies was also longer (ES = very large). Heart rate was similar during AFT and MOR matches, but higher rates of perceived exertion (ES = moderate) were reported in the AFT. Only peak running velocity was observed to be likely higher for losers than for winners (ES = small). Conclusions: Game activity and physiological responses of young tennis players differ when 2 consecutive matches are played on the same day. These data might help elucidate the need for specific precompetition training loads and/or between-matches/sessions recovery strategies when facing overloaded competitions.

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Ralph Beneke and Renate M. Leithäuser

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Stephen P. Bailey, Julie Hibbard, Darrin La Forge, Madison Mitchell, Bart Roelands, G. Keith Harris and Stephen Folger

Background: Carbohydrate (CHO) mouth rinse (MR) before exercise has been shown to improve physical performance and corticospinal motor excitability. Purpose: To determine the effects of different forms of CHO MR on quadriceps muscle performance and corticospinal motor excitability. Methods: 10 subjects (5 female and 5 male; 25 [1] y, 1.71 [0.03] m, 73 [5] kg) completed 4 conditions (placebo [PLA], 6.4% glucose [GLU], 6.4% maltose [MAL], 6.4% maltodextrin [MDX]). Maximal voluntary contraction (MVIC) of the right quadriceps and motor-evoked potential (MEP) of the right rectus femoris was determined pre (10 min), immediately after, and post (10 min) 20-s MR. MEP was precipitated by transcranial magnetic stimulation during muscle contraction (50% MVIC). Results: The relative change in MEP from pre-measures was different across treatments (P = .025) but was not different across time (P = .357). MEP was greater for all CHO conditions immediately after (GLU = 2.58% [5.33%], MAL = 3.92% [3.90%], MDX = 18.28% [5.57%]) and 10 min after (GLU = 14.09% [13.96%], MAL = 8.64% [8.67%], MDX = 31.54% [12.77%]) MR than PLA (immediately after = −2.19% [4.25%], 10 min = −13.41% [7.46%]). MVC was greater for CHO conditions immediately (GLU = 3.98% [2.49%], MAL = 5.89% [2.29%], MDX = 7.66% [1.93%]) and 10 min after (GLU = 7.22% [2.77%], MAL = 10.26% [4.22%], MDX = 10.18% [1.50%]) MR than PLA (immediately after = −3.24% [1.50%], 10 min = −6.46% [2.22%]). Conclusions: CHO MR increased corticospinal motor excitability and quadriceps muscle after application. The form of CHO used did not influence this response.

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David Morawetz, Tobias Dünnwald, Martin Faulhaber, Hannes Gatterer and Wolfgang Schobersberger

It is well known that acute hypoxia has negative effects on balance performance. An attempt to compensate for the influence of hypoxia on competition performance was made by the application of hyperoxic gases (inspiratory fraction of oxygen > 0.2095) prior to exercise. Purpose: To investigate whether hyperoxic preconditioning (pure-oxygen supplementation prior to exercise) improves balance ability and postural stability during normobaric hypoxia (3500 m) in highly skilled skiers. Methods: In this single-blind randomized, crossover study, 19 subjects performed a 60-s balance test (MFT S3-Check) in a normobaric hypoxic chamber. After a short period of adaptation to hypoxia (60 min), they received either pure oxygen or chamber air for 5 min prior to a balance test (hyperoxic preconditioning vs nonhyperoxic preconditioning). Capillary blood was collected 3 times. Results: Balance performance, indexed by sensory (P = .097), stability (P = .937), and symmetry (P = .202) scores, was not significantly different after the hyperoxic preconditioning phase. Balance performance decreased over time (no group difference). After hyperoxic preconditioning, arterial partial pressure of oxygen increased from 52.7 (4.5) mm Hg to 212.5 (75.8) mm Hg, and oxygen saturation of hemoglobin increased from 85.8% (3.5%) to 98.9% (0.7%) and remained significantly elevated to 90.1% (2.0%) after the balance test. Conclusion: A hyperoxic preconditioning phase does not affect balance performance under hypoxic environmental conditions. A performance-enhancing effect, at least in terms of coordinative functions, was not supported by this study.

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Tiago Turnes, Rogério S.O. Cruz, Fabrizio Caputo and Rafael A. De Aguiar

Purpose: The 2000-m rowing-ergometer test is the most common measure of rowing performance. Because athletes use different intervention strategies for enhancing performance, investigating the effect of preconditioning strategies on the 2000-m test is of great relevance. This study evaluated the effects of different preconditioning strategies on 2000-m rowing-ergometer performance in trained rowers. Methods: A search of electronic databases (PubMed, Google Scholar, and Web of Science) identified 27 effects of different preconditioning strategies from 17 studies. Outcomes were calculated as percentage differences between control and experimental interventions, and data were presented as mean ± 90% confidence interval. Performance data were converted to the same metrics, that is, mean power. Meta-regression analyses were conducted to assess whether performance level or caffeine dose could affect the percentage change. Results: The overall beneficial effect on 2000-m mean power was 2.1% (90% confidence limit [CL] ±0.6%). Training status affected the percentage change with interventions, with a −1.1% (90% CL ±1.2%) possible small decrease for 1.0-W·kg−1 increment in performance baseline. Caffeine consumption most likely improves performance, with superior effect in higher doses (≥6 mg·kg−1). Sodium bicarbonate and beta-alanine consumption resulted in likely (2.6% [90% CL ±1.5%]) and very likely (1.4% [90% CL ±1.2%]) performance improvements, respectively. However, some preconditioning strategies such as heat acclimation, rehydration, and creatine resulted in small to moderate enhancements in 2000-m performance. Conclusions: Supplementation of caffeine and beta-alanine is a popular and effective strategy to improve 2000-m ergometer performance in trained rowers. Additional research is warranted to confirm the benefit of other strategies to 2000-m rowing-ergometer performance.

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Sarah J. Willis, Jules Gellaerts, Benoît Mariani, Patrick Basset, Fabio Borrani and Grégoire P. Millet

Purpose: To examine the net oxygen cost, oxygen kinetics, and kinematics of level and uphill running in elite ultratrail runners. Methods: Twelve top-level ultradistance trail runners performed two 5-min stages of treadmill running (level, 0%, men 15 km·h−1, women 13 km·h−1; uphill, 12%, men 10 km·h−1, women 9 km·h−1). Gas exchanges were measured to obtain the net oxygen cost and assess oxygen kinetics. In addition, running kinematics were recorded with inertial measurement unit motion sensors on the wrist, head, belt, and foot. Results: Relationships resulted between level and uphill running regarding oxygen uptake (V˙O2), respiratory exchange ratio, net energy, and oxygen cost, as well as oxygen kinetics parameters of amplitude and time delay of the primary phase and time to reach V˙O2 steady state. Of interest, net oxygen cost demonstrated a significant correlation between level and uphill conditions (r = .826, P < .01). Kinematics parameters demonstrated relationships between level and uphill running, as well (including contact time, aerial time, stride frequency, and stiffness; all P < .01). Conclusion: This study indicated strong relationships between level and uphill values of net oxygen cost, the time constant of the primary phase of oxygen kinetics, and biomechanical parameters of contact and aerial time, stride frequency, and stiffness in elite mountain ultratrail runners. The results show that these top-level athletes are specially trained for uphill locomotion at the expense of their level running performance and suggest that uphill running is of utmost importance for success in mountain ultratrail races.