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The aim was to provide benchmarks and investigate contribution of start and turn performances in the European Short-Course Swimming Championship. Over all race distances, 932 individual races of male competitors were video captured and the start and turn performances were analysed. Start and turn performances contributed up to 26% and 56% of the total race time. Analysis of variance showed that the 15 m start times were faster for Freestyle and Butterfly (p < 0.001) compared to the other swimming strokes. In-water starts (Backstroke) were slower at the 5 m mark compare to on-block starts (p < 0.001). Tumble turns were faster than open turns (p < 0.001). Multiple linear regression analysis explained 82–97% of total variance in the race results with a decreasing effect of start performance for the longer distance races. Turn performance affected the results across all race distances (p < 0.001). The benchmarks and percentiles provide comparative data for swimmers of different performance levels. Considering the large contribution of start and turn performance to race time and the high effect in the regression model, training regimes that are mainly based on conditioning of free-swimming should be reconsidered. [ABSTRACT FROM AUTHOR]

This study aimed to optimise performance prediction in short-course swimming through Principal Component Analyses (PCA) and multiple regression. All women's freestyle races at the European Short-Course Swimming Championships were analysed. Established performance metrics were obtained including start, free-swimming, and turn performance metrics. PCA were conducted to reduce redundant variables, and a multiple linear regression was performed where the criterion was swimming time. A practical tool, the Potential Predictor, was developed from regression equations to facilitate performance prediction. Bland and Altman analyses with 95% limits of agreement (95% LOA) were used to assess agreement between predicted and actual swimming performance. There was a very strong agreement between predicted and actual swimming performance. The mean bias for all race distances was less than 0.1s with wider LOAs for the 800 m (95% LOA −7.6 to + 7.7s) but tighter LOAs for the other races (95% LOAs −0.6 to + 0.6s). Free-Swimming Speed (FSS) and turn performance were identified as Key Performance Indicators (KPIs) in the longer distance races (200 m, 400 m, 800 m). Start performance emerged as a KPI in sprint races (50 m and 100 m). The successful implementation of PCA and multiple regression provides coaches with a valuable tool to uncover individual potential and empowers data-driven decision-making in athlete training. [ABSTRACT FROM AUTHOR]

Purpose: To examine the relationship between cardiorespiratory and accelerometer-derived measures of exercise during trail running and determine the influence of accelerometer location. Methods: Eight trail runners (7 males and 1 female; age 26 [5] y; maximal oxygen consumption [ V ˙ O 2 ] 70 [6] mL·kg−1·min−1) completed a 7-km trail run (elevation gain: 486 m), with concurrent measurements of V ˙ O 2 , heart rate, and accelerations recorded from 3 triaxial accelerometers attached at the upper spine, lower spine, and pelvis. External exercise intensity was quantified from the accelerometers using PlayerLoad™ per minute and accelerometry-derived average net force. External exercise volume was calculated using accumulated PlayerLoad and the product of average net force and duration (impulse). Internal intensity was calculated using heart rate and V ˙ O 2 -metrics; internal volume was calculated from total energy expenditure (work). All metrics were analyzed during both uphill (UH) and downhill (DH) sections of the trail run. Results:PlayerLoad and average net force were greater during DH compared with UH for all sensor locations (P ≤.004). For all accelerometer metrics, there was a sensor position × gradient interaction (F2,1429.003; P <.001). The upper spine was lower compared with both pelvis (P ≤.003) and lower spine (P ≤.002) for all accelerometer metrics during both UH and DH running. Relationships between accelerometer and cardiorespiratory measures during UH running ranged from moderate negative to moderate positive (r = −.31 to.41). Relationships were stronger during DH running where there was a nearly perfect correlation between work and impulse (r =.91; P <.001). Conclusions: Simultaneous monitoring of cardiorespiratory and accelerometer-derived measures during trail running is suggested because of the disparity between internal and external intensities during changes in gradient. Sensor positioning close to the center of mass is recommended. [ABSTRACT FROM AUTHOR]

The aims of the study were to provide benchmarks and normative data for 100 m, 200 m, and 400 m short-course individual medley (IM) races, investigate differences between the various swimming strokes and turns involved in IM, and quantify the effect and contribution of various race sections on swimming performance. All IM races (n = 320) at the 2019 European Short-Course Swimming Championships were video monitored and digitized with interrater reliability described by a mean intra-class correlation coefficient of 0.968. Normative data were provided for the eight finalists of each event (FINA points = 886 ± 37) and the eight slowest swimmers from each event (FINA points = 688 ± 53). Contribution and effects of race sections on swimming performance were investigated using stepwise regression analysis based on all races of each event. Regression analysis explained 97-100% of total variance in race time and revealed turn time (β ≥ 0.53) as distinguishing factor in short-course IM races in addition to swim velocity (β ≥ -0.28). Start time only affected 100 m (β ≥ 0.14) and 200 m (β ≥ 0.04) events. Fastest turn times were found for the butterfly/backstroke turn. Breaststroke showed slowest swim velocities and no difference between fastest and slowest 100 m IM swimmers. Therefore, breaststroke may provide largest potential for future development in IM race times. Correlation analyses revealed that distance per stroke (r ≥ -0.39, P < 0.05) rather than stroke rate (r ≤ -0.18, P > 0.05) is a performance indicator and may be used by coaches and performance analysts to evaluate stroke mechanics in male IM swimmers despite its more complex assessment. Performance analysts, coaches, and swimmers may use the present normative data to establish minimal and maximal requirements for European Championship participation and to create specific drills in practice. [ABSTRACT FROM AUTHOR]

Purpose: To determine the reliability, usefulness, and validity of 3 different change-of-direction tests on a SpeedCourt (SCCODT) in team-sport players. Methods: For reliability and usefulness, 30 players (16 female and 14 male: age 19 ± 3 y, height 169 ± 30 cm, body mass 70 ±11 kg) performed 3 SCCODTS differing in duration (7--45 s) on 3 occasions 1 wk apart. The total sprint times (TT) and time to change direction (TCD) were analyzed for each SCCODT. For validity, 14 players performed the Illinois Agility Test (IAT) and 505 test on a separate occasion. Results: TT for all SCCODTS is reliable (ICC > .79, CV < 5%), useful (TE < SWC0.5), and valid (IAT r > .71, P < .05; 505 test r > .54, P < .05). SCCODT variable TCD may be useful (TE = SWC0.5) but shows limited reliability with ICC >.65 and a CV >5%. Conclusions: All SCCODTS are reliable, useful, and valid to detect moderate performance changes regarding TT, with limited reliability for TCD. The quality of assessment improves when players are well familiarized with the SCCODT [ABSTRACT FROM AUTHOR]

Purpose: The current investigation assessed tissue oxygenation and local blood volume in both vastus lateralis muscles during 3000-m race simulations in elite speed skaters on ice and the effects of leg compression on physiological, perceptual, and performance measures. Methods: Ten (6 female) elite ice speed skaters completed 2 on-ice trials with and without leg compression. Tissue oxygénation and local blood volume in both vastus lateralis muscles were assessed with near-infrared spectroscopy. Continuous measures of oxygen uptake, ventilation, heart rate, and velocity were conducted throughout the race simulations, as well as blood lactate concentration and ratings of perceived exertion before and after the trials. In addition, lap times were assessed. Results: The investigation of tissue oxygénation in both vastus lateralis muscles revealed an asymmetry (P < .00; effect size = 1.81) throughout the 3000-m race simulation. The application of leg compression did not affect oxygénation asymmetry (smallest P = .99; largest effect size = 0.31) or local blood volume (P = .33; 0.95). Lap times (P = .88; 0.43), velocity (P = .24; 0.84), oxygen uptake (P = .79; 0.10), ventilation (P = . 11 ; 0.59), heart rate (P = .21 ; 0.89), blood lactate concentration (P = .82; 0.59), and ratings of perceived exertion (P = .19; 1.01) were also unaffected by the different types of clothing. Conclusion: Elite ice speed skaters show an asymmetry in tissue oxygénation of both vastus lateralis muscles during 3000-m events remaining during the long gliding phases along the straight sections of the track. Based on the data, the authors conclude that there are no performance-enhancing benefits from wearing leg compression under a normal racing suit. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate whether upper-body compression affects power output and selected metabolic, cardio- respiratory, hemodynamic, and perceptual responses during three 3-min sessions of double-poling (DP) sprint. Method: Ten well-trained male athletes (25 ± 4 y, 180 ± 4 cm, 74.6 ± 3.2 kg) performed such sprints on a DP ski ergometer with and without a long-sleeved compression garment. Result: Mean power output was not affected by such compression (216 ± 25 W in both cases; P = 1.00, effect size [ES] = 0.00), although blood lactate concentration was lowered (P < .05, ES = 0.50-1.02). Blood gases (ES = 0.07-0.50), oxygen uptake (ES = 0.04-0.28), production of carbon dioxide (ES = 0.01-0.46), heart rate (ES = 0.00-0.21), stroke volume (ES = 0.33-0.81), and cardiac output (ES = 0.20-0.91) were also all unaffected by upper-body compression (best P = 1.00). This was also the case for changes in the tissue saturation index (ES = 0.45-1.17) and total blood content of hemoglobin (ES = 0.09-0.85), as well as ratings of perceived exertion (ES = 0.15-0.88; best P = .96). Conclusion: The authors conclude that the performance of well-trained athletes during 3 x 3-min DP sprints will not be enhanced by upper-body compression. [ABSTRACT FROM AUTHOR]

To assess original research addressing the effect of the application of compression clothing on sport performance and recovery after exercise, a computer-based literature research was performed in July 2011 using the electronic databases PubMed, MEDLINE, SPORTDiscus, and Web of Science. Studies examining the effect of compression clothing on endurance, strength and power, motor control, and physiological, psychological, and biomechanical parameters during or after exercise were included, and means and measures of variability of the outcome measures were recorded to estimate the effect size (Hedges g) and associated 95% confidence intervals for comparisons of experimental (compression) and control trials (noncompression). The characteristics of the compression clothing, participants, and study design were also extracted. The original research from peer-reviewed journals was examined using the Physiotherapy Evidence Database (PEDro) Scale. Results indicated small effect sizes for the application of compression clothing during exercise for short- duration sprints (10-60 m), vertical-jump height, extending time to exhaustion (such as running at VO2max or during incremental tests), and time-trial performance (3-60 min). When compression clothing was applied for recovery purposes after exercise, small to moderate effect sizes were observed in recovery of maximal strength and power, especially vertical-jump exercise; reductions in muscle swelling and perceived muscle pain; blood lactate removal; and increases in body temperature. These results suggest that the application of compression clothing may assist athletic performance and recovery in given situations with consideration of the effects magnitude and practical relevance. [ABSTRACT FROM AUTHOR]

To investigate the freestyle swimming sprint start performance before and after 6 weeks of maximal strength compared with vertical jump training. With a between-group repeated-measure design, 21 junior swimmers (12 female and 9 male) competing in national and international championships performed 2 weekly sessions of either maximal strength (heavy-loaded back squat and deadlift exercise) or vertical jump training (unloaded box jumps) for 6 weeks during the precompetition phase of the seasonal main event. Session ratings of perceived exertion were used to compare the load of both training programs. Before and after the training period, sprint start performance was investigated on a starting block equipped with force plates synchronized to a 2-dimensional motion capture system. Total training load did not differ between the 2 groups. Sprint start performance and most kinematic and kinetic parameters remained unaffected. In pooled data of the U17 swimmers, however, 5-m, 15-m, and 25-m split times were improved with maximal strength (p = 0.02, 0.03, and 0.01), but not with vertical jump training (p = 0.12, 0.16, and 0.28). Although there was no global effect, focus on the subgroup of U17 swimmers showed an improved sprint start performance with 2 sessions of maximal strength training integrated into a 16-hour training week. Although outcomes of the conditioning program seemed to be affected by the training history and performance level of the athletes involved, strength and conditioning coaches are encouraged to introduce maximal strength training at a young age. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effect of a repeated sprint training with multi-directional change-of-direction (COD) movements (RSmulti) compared to repeated shuttle sprints (RSS) on variables related to COD speed and reactive agility. Nineteen highly-trained male U15 soccer players were assigned into two groups performing either RSmulti or RSS. For both groups, each training session involved 20 repeated 15s sprints interspersed with 30 s recovery. With RSmulti the COD movements were randomized and performed in response to a visual stimulus, while the RSS involved predefined 180° COD movements. Before and following the six training sessions, performance in the Illinois agility test (IAT), COD speed in response to a visual stimulus, 20 m linear sprint time and vertical jumping height were assessed. Both groups improved their performance in the IAT (p < 0.01, ES = 1.13; p = 0.01, ES = 0.55). The COD speed in response to a visual stimulus improved with the RSmulti (p < 0.01, ES = 1.03), but not the RSS (p = 0.46, ES = 0.28). No differences were found for 20 m sprint time (P=0.73, ES = 0.07; p = 0.14, ES = 0.28) or vertical jumping height (p = 0.46, ES = 0.11; p = 0.29, ES = 0.12) for the RSmulti and RSS, respectively. In conclusion, performance in the IAT improved with the RSmulti as well as RSS. With the RSmulti however, the COD movements are performed in response to a visual stimulus, which may result in specific adaptations that improve COD speed and reactive agility in young highly trained soccer players. [ABSTRACT FROM AUTHOR]

Purpose: Repeated-sprint training in hypoxia (RSH) was recently shown to improve repeated-sprint ability (RSA) in cycling. This phenomenon is likely to reflect fiber type-dependent, compensatory vasodilation, and therefore, our hypothesis was that RSH is even more beneficial for activities involving upper body muscles, such as double poling during cross-country skiing. Methods: In a double-blinded fashion, 17 competitive cross-country skiers performed six sessions of repeated sprints (each consisting of four sets of five 10-s sprints, with 20-s intervals of recovery) either in normoxia (RSN, 300 m; FiO2, 20.9%; n = 8) or normobaric hypoxia (RSH, 3000 m; FiO2, 13.8 %; n = 9). Before (pre) and after (post) training, performance was evaluated with an RSA test (10-s all-out sprints-20-s recovery, until peak power output declined by 30%) and a simulated team sprint (team sprint, 3 x 3-min all-out with 3-min rest) on a double-poling ergometer. Triceps brachii oxygenation was measured by near-infrared spectroscopy. Results: From pretraining to posttraining, peak power output in the RSA was increased (P < 0.01) to the same extent (29% ±;13% vs 26% ±;18%, nonsignificant) in RSH and in RSN whereas the number of sprints performed was enhanced in RSH (10.9 ±;5.2 vs 17.1 ±;6.8, P < 0.01) but not in RSN (11.6 ±;5.3 vs 11.7 ±;4.3, nonsignificant). In addition, the amplitude in total hemoglobin variations during sprints throughout RSA rose more in RSH (P < 0.01). Similarly, the average power output during all team sprints improved by 11% ±;9% in RSH and 15% ±;7% in RSN. Conclusions: Our findings reveal greater improvement in the performance of repeated double-poling sprints, together with larger variations in the perfusion of upper body muscles in RSH compared with those in RSN. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to determine the acute responses of breathing oxygen-enriched air during the recovery periods of a simulated 3 x 3-min cross-country skiing team sprint competition at simulated low altitude. Methods: Eight well-trained male endurance athletes performed two 3 x 3-min team sprint simulations on a double-poling ergometer at simulated altitude set at ~ 1800 m. During the recovery periods between the 3 x 3-min sprints, all the athletes inhaled either hyperoxic (Fi02 = 1.00) or hypoxic (FiO2∼0.165) air in randomized and single-blind order. The mean total power output (Pmean tot) ar>d tne mean power output of each sprint (Pmean 1.2,3) were determined. Perceived exertion, capillary oxygen saturation of hemoglobin, partial pressure of oxygen, and blood lactate concentration were measured before and after all the sprints. Results: No differences in Pmean tot were found between hyperoxic (198.4 ± 27.1 W) and hypoxic (200.2 ± 28.0 W) recovery (f = 0.57, effect size [d] = 0.07). Pmean 1,2,3 (P> 0.90, d= 0.04-0.09) and RPE (P> 0.13, d= 0.02-0.63) did not differ between hyperoxic and hypoxic recovery. The partial pressure of oxygen (P< 0.01, d= 0.06-5.45) and oxygen saturation (P<0.01, d = 0.15-5.40) during hyperoxic recovery were higher than those during hypoxic recovery. The blood lactate concentration was also lower directly after the third sprint (P = 0.03, d = 0.54) with hyperoxic recovery. Conclusion: Results indicate that trained endurance athletes who inhale 100% oxygen during recovery periods in a cross-country skiing team sprint at low altitude do not exhibit enhanced performance despite the improvement in the key physiological variables of endurance performance. [ABSTRACT FROM AUTHOR]