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A lot of talented children aspire to be professional athletes. They spend many hours each week practicing and competing in the hope of achieving this. To what extent should a parent permit, encourage or even force them to do so? Professional sporting success provides substantial goods and rewards. However, trying to achieve it imposes many costs on children, such as the diminishment of important childhood goods. I argue that these costs outweigh the potential rewards, especially given the improbability of success, and so parents should not try to maximise their children's talents for professional success. I also show that how one weighs up the costs and rewards depends on one's conception of childhood. Finally, I suggest that parents, qua member of society, may well have good reason to maximise their child's talent, given the social benefits talent maximisation provides. I conclude by arguing that this does not outweigh parents' duty to provide a good childhood for their children, which talent maximisation undermines. [ABSTRACT FROM AUTHOR]

Purpose: Study on the effect of psychological skills training on self-esteem (SE) in young athletes. Method: 10 swimmers and 35 volleyball players, split into an intervention group (25) and a control group (18). The intervention entailed a 3-week psychological skills training program covering arousal management, breathing, relaxation, mental imagery, and self-talk. Multilevel growth curve analyses evaluated SE changes. Results: The intervention group showed significant improvements in multiple SE dimensions—physical self-worth, fitness, athletic competence, strength, and body attractiveness but not general SE. Conclusions: This study provides initial evidence of a multimodal psychological skills training's effectiveness in enhancing young athletes' domain-specific SE. It highlights the role of domain-specific SE in young athletes' well-being. Future research should examine psychological and physiological correlations and assess the long-term SE development in adolescent athletes. [ABSTRACT FROM AUTHOR]

Purpose: To determine the acute response of lactate supplementation on athletic performance. Method: Fifteen athletes under the age of 15 performed the following 4 sessions in a nonrandomized order: (1) familiarization, (2) control, (3) participants ingested calcium lactate (21.5 mg·kg−1 body mass), and (4) participants ingested a placebo (PLA, calcium carbonate, 21.5 mg·kg−1 body mass). The capsules were randomly offered and consumed 60 minutes before the physical tests. To assess the physical performance, the athletes executed squat jump, countermovement squat jump, 20-m linear sprint, change of direction test, and running anaerobic sprint test. Results: There were no significant differences between conditions for squat jump, countermovement jump, change of direction, and minimum power obtained in the running anaerobic sprint test (P >.05). Conversely, we observed a worse performance (P <.05) in the 20-m linear sprint test in the PLA and lactate conditions compared with control (P <.05). The lactate condition worsened performance during running anaerobic sprint test for peak power, mean power, and fatigue index compared with control and PLA (P <.05). Conclusions: Calcium lactate supplementation worsened repetitive running sprint ability and 20-m sprint performance. However, lactate supplementation does not affect jump or agility capacity. Therefore, calcium lactate supplementation seems to be an ineffective strategy to improve anaerobic and neuromuscular performance in soccer players 15 years of age or less. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to investigate the effect of agility ladder training combined with plyometric or multidirection speed drills, on performance in young female volleyball players. Methods: Seventy-six young female volleyball players were randomly distributed into 3 maturity-matched groups: (1) the agility ladder + plyometric drills group, (2) the agility ladder + multidirection speed drills group, and (3) the control group. Both experimental groups followed a 6-week training program, twice weekly, in addition to the regular volleyball training sessions, while the control group participated only in the regular volleyball training sessions. Assessments pretraining and posttraining included countermovement jump, 20-m sprint, and agility T test. Results: Both experimental groups improved T-test performance (P <.005) but only agility ladder + multidirection speed drills group outperformed the control group (P <.05). Conclusions: Agility ladder training programs combined with either plyometric or speed drills can improve change of direction performance in young female volleyball players but only the combination of agility ladder with multidirection speed drills is more effective than volleyball training per se. The small effectiveness of these protocols may be attributed to the short training period, or to the fact that training elements were combined in a single session. This hypothesis remains to be further investigated. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to explore the interday reliability of mechanical variables obtained from the horizontal and vertical force–velocity (FV) profiles in adolescent female basketball players. If found to be reliable, the associations between FV parameters (theoretical maximal force, velocity, and power), squat jump (SJ) height, 30-m sprint, and change of direction (COD) times were evaluated. Methods: After familiarization, SJ against incremental loads, 30-m sprint, and 505-COD tests were obtained twice in 36 adolescent female basketball players (age = 15.4 [1.2] y). Results: Reliability for vertical FV parameters was unacceptable, whereas 505-COD times and FV horizontal parameters (except for theoretical maximal power) showed a moderate to high reliability. 505-COD time was correlated with FV horizontal parameters (range: r = −.821, −.451), and a large association was observed with both SJ height (r = −.678, −.600) and 30-m sprint time (r =.813,.858). Conclusions: Due to low levels of strength, our athletes were not adequately prepared to obtain a reliable vertical FV profile. Practitioners can expect acceptable reliability of the horizontal FV profile. Given the association between COD performance and SJ height and 30-m sprint time, we encouraged practitioners with limited equipment at their disposal to use COD and/or 30-m sprint tests. [ABSTRACT FROM AUTHOR]

This study critically examines the suitability of using a single drop height to assess the reaction strength index in trained and active participants, a key component of athletic performance. Using a cross-sectional design, 377 trained (n = 163) and active (n = 214) participants aged 14–18 years performing drop jumps from 4 different heights (24, 32, 40, and 48 cm) were studied. The primary aim was to explore the individual differences in reaction strength index at these heights and to assess whether a single height can reliably represent stretch-shortening cycle capabilities. While the repeated measures analysis of variance did not reveal any significant differences, the Bland–Altmann analysis revealed significant individual discrepancies between the performance of the drop heights, resulting in a mean absolute error of 32.1 and a mean absolute percentage error of 20.6%. These results strongly suggest that a single drop height is not sufficient to determine performance in the stretch-shortening cycle. This has important practical implications as it can lead to underestimates of performance trends. The study advocates the inclusion of a range of drop heights in routine testing to accurately measure reactive power and thus improve the effectiveness of individualized training programs for young athletes/active youth. [ABSTRACT FROM AUTHOR]

Humans are fascinated by the bipedal locomotor capacities at both ends of the athletic spectrum—sprinting speed and endurance. Some of the more popular field (eg, soccer, rugby, and lacrosse) and court (eg, basketball, tennis, and netball) sports utilize mixed energy systems requiring an interplay of both maximal sprinting speed (MSS) and maximal aerobic speed (MAS) to meet the high-intensity running demands of varying frequency, duration, intensity, and recovery. Recently, these locomotor capacities have been considered in combination to produce what is called the anaerobic speed reserve (ASR) as part of the locomotor profile concept (MSS, MAS, and ASR). The purpose of this narrative review is to (1) provide an overview of the locomotor profile concept; (2) review the assessment methods for estimating MSS, MAS, and ASR; (3) examine the age-, sex-, and maturity-associated variations in MSS, MAS, and ASR; (4) examine the trainability of MSS, MAS, and ASR in youth athletes; and (5) conclude with the practical applications using principles of long-term athlete development for training the locomotor profile in youth field and court sport athletes. Based on the available data in young male athletes, MSS, MAS, and ASR generally increase with age and across maturity groups and are trainable. Overall, decisions on training need to consider the sport demands, current fitness and maturity status, and targeted training adaptation sought. [ABSTRACT FROM AUTHOR]

Background: Phase angle (PhA) is an indicator of cellular health, function, and integrity. PhA has been considered an indicator of nutritional and health status, but it is uncertain whether it could be used as a fitness or athletic performance indicator. Objective: To analyze the relationship between PhA and the fitness and athletic performance of adolescent boxers and to know whether this association is independent of body composition. Methods: Thirty-seven trained youth boxers (15–18 y old) participated in the study. Participants underwent anthropometry and bioelectrical impedance assessments. The following tests were conducted: Fitness-Gram battery; speed, agility, and quickness; ball throws; punch impact force; bench press maximal strength; and vertical and horizontal jumps. Linear regression models were estimated and adjusted by covariates. Results: The PhA was related to upper-limb strength. Nevertheless, in linear regression models, after adjusting models by body composition, only PhA remained as a predictor of relative maximal strength. The PhA was not a predictor of speed, agility, and quickness; cardiorespiratory fitness; or lower-limb power, in which adiposity was the main predictor of fitness. Conclusions: In adolescent boxers, PhA can predict upper-limb maximal strength independently of bioelectrical impedance analysis premises. However, compared with mucle mass, PhA is not a better predictor of upper-limb maximal strength. [ABSTRACT FROM AUTHOR]

Purpose: To compute reference centiles for 5- and 30-m sprint times relative to chronological and skeletal age in youth soccer players. Subsequently, to compare individual's sprint performance scores derived from the chronological and skeletal age reference centiles. Methods: Sprint times were collected for a sample of male U11 to U19 soccer players (n = 1745 data points). Skeletal age data were available for a subsample (n = 776 data points). Reference centiles were fitted using generalized additive models for location, scale, and shape. Individual z scores relative to chronological and skeletal age reference centiles were computed and compared for each maturity group (late, on-time, early, and very early) using standardized mean differences (SMD). Results: Reference centiles for chronological age increased more rapidly between 10.5 and 15.5 years, while reference centiles for skeletal age increased more rapidly between 13.0 and 16.5 years. Differences in chronological and skeletal z scores for very early (SMD: −0.73 to −0.43) and late (SMD: 0.58 to 1.29) maturing players were small to large, while differences for early (SMD: −0.30 to −0.19) and on-time (SMD: 0.16 to 0.28) were trivial to small. Conclusion: Reference centiles provide a valuable tool to assist the evaluation of sprint performance in relation to chronological and skeletal age for talent identification purposes in youth soccer players. [ABSTRACT FROM AUTHOR]

Traditionally, sports participation has been based on the chronological age of the individual with year of birth determining participation grouping. However, grouping by chronological age can result in individuals who are nearly a full year different in age competing within the same age group. Moreover, during the pubertal years, age grouping may provide physical (size) advantage to early maturers and disadvantage to late maturers. These advantages/disadvantages could impact talent selection, psychosocial aspects of sport participation, technical and tactical skill development, competitiveness, and injury risk. Biobanding is an alternative method for determining sport participation categorization and uses factors of growth and/or maturation, rather than traditional chronological age, for grouping athletes. Implementation of biobanding in sports may be advantageous to both early and late-maturing athlete development. [ABSTRACT FROM AUTHOR]

Purpose: Antarctic expeditions are exceptional physiological challenges. Sleep plays a critical role in athletic performance, recovery, and wellness, with sleep disturbances having a negative impact on health and performance. Methods: The authors investigated sleep, fatigue, and recovery profiles of the longest solo unsupported one-way polar ski journey across Antarctica. A 33-year-old woman covered 1484.53 km from Hercules Inlet to the South Pole, finishing at the Ross Ice Shelf, in 70 days and 16 hours. Questionnaires on sleep (Pittsburgh Insomnia Rating Scale and Karolinska Sleepiness Scale), fatigue (Subjective Assessment of Fatigue), recovery (Total Quality Recovery), and wellness were completed at different time points (before, during, and after the expedition). Results: Average daily sleep time was between 4 and 5 hours, increasing to 7 hours for the final part of the expedition. Satisfaction of sleep and lack of energy deteriorated as the expedition progressed, alongside signs of clinical insomnia. Fatigue and muscle soreness increased with increasing milage, with extreme levels and very poor recovery toward the end of the expedition. Despite this, the adventurer continued to perform on extremely high levels. Postexpedition scores returned to baseline, demonstrating the incredible adaptation and ability to recovery. The postexpedition interview showed that prior experience of an Antarctic expedition may have prepared the athlete and made her more resilient for this challenge. Conclusions: The data provide unique insights into Antarctic expeditions and may help us understand the limits of human performance when planning future expeditions of this nature. Female athletes are capable of extreme challenges, breaking established performance boundaries. [ABSTRACT FROM AUTHOR]

Objective: Passive stiffness, a biomechanical parameter, has a potential influence on running economy, thus playing a pivotal role in performance. This study aimed to quantify passive stiffness of the Achilles tendon and gastrocnemius muscle using myotonometry throughout an incremental running protocol. Methods: Twenty-one male participants underwent a multistage incremental test (Bordeaux test) on a treadmill until exhaustion. Passive stiffness of the gastrocnemius muscle and Achilles tendon was measured using a MyotonPRO device. Measurements were taken before, during, and after the incremental test. Results: Our findings indicated that passive stiffness of the medial gastrocnemius decreased at rest between prerun and postrun assessments (−20.12 N·m−1, P =.012). Furthermore, during the test, stiffness increased at low intensity (at 50% of maximal aerobic speed: +104.8 N·m−1, P =.042), returning to baseline values as intensity increased. Conclusions: Throughout an incremental running protocol, both Achilles tendon and gastrocnemius muscle stiffness initially increased and then decreased with escalating percentages of maximal aerobic speed. A deeper understanding of stiffness in running can inform more effective recommendations for runners' strengthening and training. [ABSTRACT FROM AUTHOR]

Purpose: The current study aimed to determine the effect of a synthetic-grass sport surface on core body temperature, skin temperature, heart rate, thermal sensation, thermal comfort, and rating of perceived exertion (RPE) during intermittent exercise in hot conditions. Methods: Using a randomized crossover design, 13 trained/developmental team-sport athletes completed two 50-minute standardized intermittent running protocols on a synthetic and a natural-grass surface, on separate days (control-condition air temperature 32.6 °C [1.3 °C], relative humidity 43.2% [5.3%]). Results: Final skin temperature was significantly higher on synthetic compared with natural grass at the calf (40.1 °C [2.5 °C] vs 33.4 °C [0.6 °C]; P <.001), shoulder (36.6 °C [1.7 °C] vs 33.7 °C [0.7 °C]; P <.001), and chest (33.2 °C [1.1 °C] vs 31.8 °C [1.2 °C]; P =.02). Thermal sensation (median: 2.3; interquartile range [0.5] vs 2.2 [0.5], P =.03) and sweat rate (1.5 [0.4] L·h−1 vs 1.2 [0.3] L·h−1; P =.02) were also significantly higher on synthetic grass. While final core body temperature was significantly higher on the natural than synthetic grass (38.4 °C [0.3 °C] vs 38.2 °C [0.4 °C]), there were no significant differences in delta core temperature, as well as heart rate, thermal comfort, or RPE. Conclusions: Higher skin temperatures, thermal sensation, and sweat rates suggest that exercising on synthetic grass in hot conditions may increase some markers of heat strain during exercise. However, delta core body temperature, heart rate, thermal comfort, and RPE remained unaffected. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to investigate the effects of acute ischemic preconditioning (IPC) on tennis skill and physical exercise performance, as well as to explore whether 7-day repeated IPC (RIPC) accelerated fatigue recovery after a simulated tennis match. Methods: Twenty-nine male tennis-specific current students were randomly allocated into 1 of 2 groups: SHAM (n = 14, 3 × 5 min at 20 mm Hg) and IPC (n = 15, 3 × 5 min at 220 mm Hg). Participants in both groups engaged in acute IPC and RIPC interventions. After the first acute IPC intervention, assessments were conducted to evaluate tennis-specific skills and overall physical exercise capacity. Following completion of chronic RIPC interventions, all participants competed in a simulated tennis match specifically designed to induce fatigue. To evaluate recovery from this induced fatigue, physical exercise capacity tests were conducted at 24 and 48 hours postmatch, allowing for an assessment of the participants' recovery capabilities over time. Results: After the first acute intervention, notable differences were observed between the IPC and SHAM groups in their performance on the repeated-sprint ability test. Specifically, the total times recorded were significantly shorter in the IPC group compared with the SHAM group (IPC: 109.05 [2.70] vs SHAM: 114.57 [7.45] s, P =.012), and this trend was also reflected in their best times (IPC: 4.20 [0.18] s vs SHAM: 4.39 [0.30] s, P =.042), indicating an immediate benefit of the IPC intervention on sprint performance. After a 7-day RIPC intervention, significant changes were noted in the SHAM group's performance metrics postmatch. There was an increase (P <.001) in fatigue index from 22% (8%) to 30% (9%) during repeated-sprint ability test and a decrease in serve speed from 120.2 (17.5) to 106.7 (13.0) km/h (P =.002) and knee peek torque from 196.0 (49.0) to 162.7 (39) N (extension, 60°/s, P <.001) in the SHAM group 24 hours postmatch, relative to the IPC group. Moreover, compared with the SHAM group, the IPC group showed a lower rate of perceived exertion during the match (P <.001) and a decrease in visual analog scale score (P =.026) 24 hours postmatch, suggesting enhanced recovery and reduced perception of pain relative to the SHAM group. Conclusion: IPC could serve as a strategy to generate an ergogenic effect and recovery during training and competition. [ABSTRACT FROM AUTHOR]

The decision of the Union Internationale de Pentathlon Moderne to replace horse riding with Obstacle after the 2024 Olympic Games challenges training, testing, and recovery management in Modern Pentathlon. This commentary discusses physiological, technical, and tactical effects of rule changes in the 5 disciplines with a specific focus on the new discipline Obstacle. Modern Pentathlon requires athletes to develop specific endurance capacities relying on both the aerobic and anaerobic systems while simultaneously increasing lower- and upper-body strength capabilities. In addition, movements must be repeatedly executed in an explosive and precise manner. Running and swimming must be fast but economical. Swapping from horse riding to Obstacle will prioritize the explosive strength of the upper extremities and core while keeping high levels of endurance and precision in swimming, fencing, and shooting. Moreover, condensing the Modern Pentathlon competition to a 90-minute television-friendly format enables more competitions in the future. Athletes and coaches will thus also need to develop and maintain effective individual peri-exercise routines (before, during, and after the competition) to successfully meet the resulting tactical and physical challenges of the new format. This commentary aims to stimulate the discussion on the effect of the Union Internationale de Pentathlon Moderne's decisions to replace riding with the new Obstacle discipline and implement a more television-friendly format with a focus on physiological, technical, and tactical aspects. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect of a newly developed hand rim in wheelchair tennis players from a lab and field perspective. Methods: Nine wheelchair tennis players performed a set of field and lab tests with the new rim (NR) and regular rim on the racket side. Each player had a 60- to 120-minute regular training session with the NR. Three wheelchair tennis field tests (20-m sprint, Illinois, spider) were completed on a hard court using inertial measurement units. The inertial measurement units enabled analysis of linear/rotational velocity and acceleration. In the lab, two 4-minute submaximal tests (at 1.5 and 2 m/s, 0.2 W/kg), followed directly by a 5-second sprint, on a wheelchair ergometer were completed. Force and velocity were measured continuously throughout all tests. Mixed linear models investigated the effect between the 2 hand rims. Results: During the spider test, mean rotational velocity to the racket side (−2%, P =.005) was lower in the NR, and end times were similar between hand-rim conditions. No differences were observed in the 20-m sprint and Illinois field tests. In the lab, contact angle (+6%, P =.04), cycle time (+12%, P =.007), and work per push (+13%, P =.005) were higher in the NR during submaximal propulsion. Work per push (+13%, P =.007), peak velocity (+3%, P <.001), and distance covered (+4%, P =.02) were higher with the NR during the 5-second sprint test. Conclusions: The NR seems slightly favorable compared with the regular rim during performance testing on a wheelchair ergometer in wheelchair tennis players. A longer practice time might show more insights between the hand-rim types. [ABSTRACT FROM AUTHOR]

Purpose: To examine the reproducibility and sensitivity of a self-paced field running test (SFT) in monitoring positive and negative changes in endurance performance. Methods: A total of 27 (11 women) recreational runners participated in a 6-week training intervention. The intervention was divided into a 3-week baseline period, a 2-week overload period, and a 1-week recovery period. An incremental treadmill test was performed before the baseline period and a 3000-m running test before and after all periods (T1–T4). In addition, the participants performed once a week an SFT (SFT1–6), which consisted of submaximal (6 + 6 + 3-min test at perceived exertion of 9/20, 13/20, and 17/20) and maximal sections (6 × 3-min intervals at maximum sustainable effort). The associations between the incremental treadmill test and the SFT1 performance were examined with the Pearson correlation, and the intraclass correlation was analyzed for the parameters of SFT1 to SFT3 sessions during the baseline period. The repeated-measures correlation was calculated for the 3000-m speed at T1 to T4 and the corresponding speeds at SFT. Results: Significant associations (r =.68–.93; P <.001) were found between the speeds of the SFT and the peak and lactate threshold speeds of the incremental treadmill test. Intraclass correlations varied between.77 and.96, being the highest for the average speed of 6 × 3-minute intervals. Repeated-measures correlation was significant (P <.05) for the 9/20 (r =.24), 13/20 (r =.24), and 6 × 3-minute intervals (r =.29). Conclusions: The SFT seemed a reproducible method to estimate endurance performance in recreational runners. The sensitivity to track short-term and small-magnitude changes in performance seems more limited and might require more standardized conditions. [ABSTRACT FROM AUTHOR]

Objectives: Assess the effect of water dousing on heat strain and performance during self- and fixed-paced exercise in the heat. Design: Crossover, block-randomized controlled trial. Methods: Thirteen trained runners completed a 10-km time trial (TT) and 60-minute fixed-pace run (60% velocity of V ˙ O 2 max) in a 30.4 °C, 47.4% relative humidity environment using either water dousing (DOUSE) or no dousing (CON). Results: Ten-kilometer TT performance was faster in DOUSE compared to CON (44:11 [40:48, 47:34] vs 44:38 [41:21, 47:56] min:s; P =.033). Change in core temperature (Tc) was not different between groups during the TT (+0.02 [−0.04, 0.07] °C in DOUSE; P =.853) or fixed-pace run (+0.02 [−0.15, 0.18] °C; P =.848). Change in mean skin temperature was lower in DOUSE during the TT (−1.80 [−2.15, −1.46] °C; P <.001) and fixed-pace run (−1.38 [−1.81, −0.96] °C; P <.001). Heart rate was lower for DOUSE during the fixed-pace run (−3.5 [−6.8, −0.2] beats/min; P =.041) but not during the TT (−0.2 [−2.5, 2.1] beats/min; P =.853). Thermal sensation was lower for DOUSE during the TT (−49.3 [−72.1, −26.1] mm; P <.001) and fixed-pace run (−44.7 [−59.7, −29.6] mm; P <.001). Rating of perceived exertion was not different between groups for the TT (−0.2 [−0.7, 0.3]; P =.390) or fixed-pace run (−0.2 [−0.8, 0.4]; P =.480). Sweat rate was lower for DOUSE for the TT (−0.37 [−0.53, −0.22] L/h; P <.001) and fixed-pace run (−0.37 [−0.48, −0.26] L/h; P <.001). Conclusion: Water dousing improves 10-km TT performance in the heat but does not affect Tc. The positive change in thermal perception (via lower skin temperature) during the TT likely drives this benefit. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to compare running economy across habituated and nonhabituated advanced footwear technology (AFT) in trained long-distance runners. Methods: A total of 16 participants completed up to six 5-minute trials in 1 to 3 pairs of their own habituated shoes and 3 different and standardized AFTs at individual marathon pace. We measured oxygen uptake and carbon dioxide production and expressed running economy as oxygen uptake (in milliliters oxygen per kilogram per minute), oxygen cost of transport (oxygen per kilogram per minute), energetic cost (in watts per kilogram), and energetic cost of transport (in joules per kilogram per kilometer). We used linear mixed-effect models to evaluate differences. Relative shoe weight and shoe mileage (distance worn during running) were covariates. Results: Forty-eight standardized and 29 individual AFT conditions were measured (mileage 117.0 [128.8] km, range 0–522 km; 25 habituated 135.7 [129.2] km, range 20–522 km; 4 nonhabituated 0 [0] km, range 0–0 km). Rating of perceived exertion, blood [La], and respiratory exchange ratio ranged from 9 to 15, 1.11 to 4.54 mmol/L, and 0.76 to 1.01. There was no effect for habituation on energetic cost of transport (thabituation = −.232, P =.409, b = −0.006; 95% CI, −0.058 to 0.046) or other running economy metrics. Neither shoe weight nor shoe mileage had an effect. Conclusions: Our results suggest that habituation to AFTs does not result in greater benefits in the use of AFTs. This means that implementation in training may not be needed, even if we cannot rule out any other possible benefits of habituation at this stage, such as adaptation of the musculoskeletal system. [ABSTRACT FROM AUTHOR]

Purpose: This study compared the physiological profiles and energy-system contributions of trained football players engaged in regular-passing and third-man-passing small-sided games (SSGs) that included 4 versus 4 and a goalkeeper. Methods: Ten male trained football players participated in this crossover study. All participants were randomly assigned to either regular-passing SSG or third-man-passing SSG (4 vs 4 with a goalkeeper, 35-m × 17-m pitch size, and 6-min match duration). During these SSGs, physiological parameters including peak and mean heart rate, oxygen uptake ( V ˙ O 2 peak and V ˙ O 2 mean), metabolic equivalents in V ˙ O 2 peak and V ˙ O 2 mean , and blood lactate concentrations (peak La− and delta La− [Δ La−]), were measured. Energy contributions (oxidative [WOxi], glycolytic [WGly], and phosphagen [WPCr] systems) and Global Positioning System (GPS) variables (total distance, total acceleration counts, mean speed, and maximum speed) were also analyzed. Results: No significant differences in physiological parameters and GPS variables were found between regular- and third-man-passing SSGs. WOxi in kilojoules and percentages was significantly higher during both SSGs than WPCr and WGly (P <.0001, respectively). WPCr and WPCr + WGly values during third-man-passing SSGs were significantly higher than those during regular-passing SSGs (P <.05). Additionally, low to moderate positive correlations were observed between WOxi, WGly in kilojoules, V ˙ O 2 peak , V ˙ O 2 mean , peak La−, Δ La−, total acceleration counts, and mean speed (r =.39–.64). Conclusions: Third-man-passing SSGs may be useful for increasing anaerobic capacity. More third-man-passing SSG sessions in preparation for football games may support high metabolic power and repeated powerful anaerobic performances in trained football players. [ABSTRACT FROM AUTHOR]

Purpose: Jump and linear sprint performances both correlate with pro-agility performance. However, correlation does not imply causation, and potential confounders may affect the correlation. Therefore, this study aimed to determine the relationship between change-of-direction (COD) performance and COD deficits (COD-D) in linear-sprint and countermovement-jump (CMJ) -related performance using multiple stepwise linear-regression models. Methods: The study included 42 female national-level intercollegiate athletes. The 10- and 20-m linear-sprint and pro-agility times, COD-D, CMJ height, and phase-specific force production and rate of force development during eccentric unloading, eccentric braking, and the concentric phases of CMJ were measured. Stepwise linear-regression analyses were used to predict the factors related to COD and COD-D. Results: CMJ height was the sole predictor in the 10-m pro-agility model (adjusted R2 =.234, P =.001). Modified Reactive Strength Index (standardized coefficient, −.710) and the lowest center-of-mass depth during the CMJ (standardized coefficient,.323) were predictors in the 20-m pro-agility model (adjusted R2 =.330, P <.001). For the 10- and 20-m COD-D models, the rate of force development at 30 and 60 milliseconds, respectively, during the concentric phase was the only predictor of performance (adjusted R2 =.183, P =.003 and.237, P =.001, respectively). Conclusions: These results suggest that athletes should concentrate on improving their CMJ height, increasing their ability to lower their center of mass more deeply, and increasing their instantaneous force-production abilities immediately after the eccentric braking phase of CMJ to improve their COD performance. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the training and development process of a multiple-Grand-Slam finalist. Methods: A mixed-methods case-study design was used to capture the quantitative and qualitative aspects related to the training and successful development process. We used a 3-step data-collection process and pragmatic analyses of (1) training history based on logs, plans, and questionnaires; (2) in-depth semistructured interviews with the player's head coach/father, physical coach, and team administrator/mother; and (3) systematic quality assurance through negotiation among researchers and all key informants, including the player. Results: The player's exceptional performance level was achieved by a progressive, nonlinear increase in annual training load during childhood and early youth, stabilizing at 800 sessions and 1250 to 1300 hours per year at the age of 19. The annual tennis-specific training plateaued at ∼750 hours from the age of 15, and 60 to 80 matches were played in most of the analyzed years. Point-play accounted for approximately 50% of the total amount of specific tennis training, clearly ahead of ground strokes (∼30%), serve/return (∼15%), and smash/volley (∼5%). Physical-conditioning hours increased 5-fold from 12 to 19 years, before stabilizing at ∼500 hours at senior age. Key success factors included the athlete's multidimensional sports talent, discipline, and inner drive; a highly dedicated father and tennis-enthusiastic family; and strong support from a complementary and interdisciplinary performance team. Conclusion: This study provides novel information regarding the training and development process for a world-leading tennis player, providing a point of departure for the development of future talents. [ABSTRACT FROM AUTHOR]

Purpose: The traditional understanding of how coaches plan for sporting performance is rooted in the assumption that coaches create periodized plans underpinned by physiological principles, thereby providing scientific credibility to their work. In contrast, there remains a paucity of literature exploring how coaches understand or think about their planning practices. The purpose of this study was to generate new knowledge regarding what information coaches actually consider within their planning processes and how they actually approach the task of planning. Method: Using rigorous, in-depth interviews, this study examined athletics coaches' understandings of their everyday planning practices, in an attempt to contribute to narrowing the gap between academic research and real-world application. Twenty-eight highly experienced, high-performance track-and-field coaches based in England (female, n = 1; male, n = 27) were recruited. The coaches were from the throwing disciplines (n = 10) and endurance running (n = 18). Coaches were interviewed about their planning process, using a maximum of 3 semistructured interviews per coach, spaced across a full athletics season. In total, this generated 68 hours of data. Results: The analysis demonstrated that, while the participant coaches utilized the principles of periodization, their planning activities were not limited to this issue. The findings highlighted how the coaches conceptualized successful athletic performance in a holistic way; that is, planning is multifaceted in nature. Conclusion: This study presents a holistic picture of the complexity of coaches' planning, detailing the considerable time and attention given to planning for athletes' psychological, personal, and social development, to enhance athlete performance and development. [ABSTRACT FROM AUTHOR]

Purpose: To compare power output and pacing between maximal 1500- and 2000-m on-water rowing performances. Methods: Twenty-six (female n = 4, male n = 22) international rowers, across 6 boat classes, completed maximal 1500- and 2000-m on-water races, separated by 24 to 48 hours. Crew combinations and seat orders remained consistent between races. Peach PowerLine instrumentation measured power output and stroke rate. Differences in completion time, mean power output (MPO), percentage prognostic velocity (PPV; percentage of world record velocity in each boat class), stroke rate, and pacing variance were assessed using linear mixed modeling. Results: Compared with 2000-m, completion times were 90.4 (6.1) seconds shorter over 1500 m (−24.7% [0.7%]). Both MPO (P =.255, η p 2 =.06) and PPV (P =.340, η p 2 =.18) were not different between distances. Broadly, crews adopted a reverse-J-shaped pacing across both distances, demonstrating a reduced variance over 1500 m (P =.035, η p 2 =.62). Percentage change in MPO from 2000 to 1500 m demonstrated a strong negative association with pacing variance over 1500 m (R2 =.74, P =.027). Conclusions: International rowing crews did not increase MPO or PPV when racing maximally over 1500 m compared to 2000 m. Comparable strategies were adopted over both distances, with less variance in pacing observed over 1500 m. The crews that demonstrated greater increases in MPO over the shorter race employed a flatter pacing strategy. To improve 1500-m on-water performance, rowers may need to adopt a more even pacing approach. [ABSTRACT FROM AUTHOR]

Purpose: To assess the effect of whole-body cryotherapy (WBC) on postmatch recovery in basketball. Methods: Using a crossover design, 17 youth male players (age 16.2 [1.2] y, stature 190.5 [9.4] cm, body mass 79.2 [9.6] kg, experience 9.9 [3.9] y) completed 2 simulated matches, followed by WBC (4 min, −75 to − 85 °C) or a placebo intervention (CON). Countermovement-jump height, change-of-direction performance, 10- and 20-m sprint times, heart-rate variability (log-transformed squared root of the mean sum of the squared differences between R-R intervals [Ln-rMSSD]), muscle soreness, and perceived recovery (Perceived Recovery Status Scale [PRS]) were recorded at prematch, postmatch, postrecovery, and 24 hours postmatch. Additionally, Ln-rMSSD was recorded upon awakening on match day and the following morning. Results: Compared with CON, higher PRS values were reported in WBC at prematch and postrecovery (P ≤.026), while no significant between-interventions differences were found for any other measure (P >.05). Regarding the effect of time, our findings revealed that 20-m sprint times, Ln-rMSSD, and PRS deteriorated in both interventions from prematch to postmatch (ie, acute changes, P ≤.045), while muscle soreness worsened in WBC only (P ≤.003). Conversely, countermovement-jump height, change-of-direction, and 10-m sprint performance were unaffected by match play in the acute phase (P >.05), while none of the investigated measures showed impairments at 24 hours postmatch, compared with prematch (P >.05). Conclusions: Overall, these findings suggest that WBC was mostly ineffective for improving postexercise recovery in the investigated sample, with benefits observed for perceived recovery being potentially influenced by the participants' status at baseline (ie, higher prematch PRS scores in WBC compared with CON). [ABSTRACT FROM AUTHOR]

Purpose: To describe and compare the race characteristics, demands, and durability profile of a male and a female Grand Tour winner. Methods: Overall and stage-type-specific (ie, time trials, flat, semimountainous, and mountain) demands and race characteristics during 2 Grand Tours were determined and compared between the female and male cyclists. In addition, relative power output distribution and pacing, percentage of functional threshold power (FTP), and changes in maximal mean power outputs (MMPs) with increasing levels of kilojoules burned were determined. Results: Although many differences were found between course and absolute racing demands between the male (FTP: 413 W; critical power: 417 W) and female (FTP: 297 W; critical power: 297 W) cyclists, similar power distributions and pacing strategies were found if data were expressed relatively. However, the female cyclist rode a higher percentage of her FTP during the first 2 quarters of flat stages (14.7%–15.1%) and the last quarter of mountain stages (9.8%) than the male cyclist. Decrements in MMPs were only observed after burning 30 kJ·kg−1 in the female and 45 kJ·kg−1 in the male Grand Tour winner. Conclusions: Both the male and female Grand Tour winners produced very high 20- to 60-minute MMPs, whereas decrements in MMPs were only observed after having burned 75% (female) and 80% (male) of total kilojoules burned during a stage. These are the latest and lowest in MMPs reported in the scientific literature and highlight the importance of durability in combination with excellent climbing and time-trial skills, which are needed to be able to win a Grand Tour. [ABSTRACT FROM AUTHOR]

Purpose: To gather information on practices and perceptions of high-performance experts regarding their athletes' muscle fiber-type composition (MFTC) and its estimation. Methods: A questionnaire on the noninvasive versus invasive estimation of MFTC was completed by 446 experts including coaches and sport-science/sports-medicine staff. Moreover, the perceived importance of MFTC for training and performance optimization was assessed. Differences between sport types (individual and team sports) were analyzed using chi-square tests. Results: Forty percent of the experts implemented MFTC assessment in pursuit of performance optimization, while 50% did not know their athletes' MFTC but expressed a desire to implement it if they would be able to assess MFTC. Ten percent did not perceive value in MFTC assessment. Only 18% of experts believed that their athletes would undergo a muscle biopsy, leading to the adoption of alternative noninvasive techniques. Experts primarily relied on their experience to estimate MFTC (65%), with experts working in individual sports using their experience more frequently than those working in team sports (68% vs 51%; P =.009). Jump tests emerged as the second-most commonly employed method for estimating MFTC (56%). When only considering experts who are currently using MFTC, 87% use MFTC to individualize training volume and 84% to individualize training intensity. Conclusions: Experts value MFTC assessment primarily to individualize training but mainly rely on noninvasive methods to estimate MFTC. Some of these methods lack scientific validity, suggesting a continuing need for education and further research in this area. [ABSTRACT FROM AUTHOR]

Background: The benefits of oral caffeine intake to enhance several aspects of physical performance, such as aerobic endurance, strength, power, and muscle endurance performance, are well supported. However, how the physical performance benefits of caffeine supplementation are translated into better specific actions in intermittent sports during real or simulated competition has been the topic of fewer investigations, and their results need to be appropriately reviewed and meta-analyzed. Objective: The aim of the study was to investigate the effects of acute caffeine intake on specific actions in intermittent sports involving decision making and high-intensity efforts (eg, team, racket, and combat sports) during real or simulated competitions. Methods: All studies included had blinded and crossover experimental designs, and we conducted a risk-of-bias analysis. In total, we included 24 studies. A meta-analysis was performed using the random-effects model to calculate the standardized mean difference (SMD) estimated by Hedges g and 95% CIs. Results: Caffeine ingestion increased high-intensity sport-specific actions during competition, such as the number of sprints (SMD: 0.48; 95% CI, 0.23–0.74), body impacts (SMD: 0.28; 95% CI, 0.08–0.49), accelerations (SMD: 0.35; 95% CI, 0.06–0.63), decelerations (SMD: 0.63; 95% CI, 0.12–1.14), and high-intensity offensive efforts (SMD: 0.36; 95% CI, 0.11–0.61). Additionally, caffeine ingestion induced a higher positive or success rate of actions during real or simulated competition (SMD: 0.44; 95% CI, 0.19–0.69). Conclusion: The current meta-analysis provides evidence of caffeine supplementation in increasing high-intensity efforts and the success rate of sport-specific actions during real or simulated competition. [ABSTRACT FROM AUTHOR]

Beta-alanine is a nonessential amino acid that is commonly used to improve exercise performance. It could influence the buffering of hydrogen ions produced during intense exercise and delay fatigue, providing a substrate for increased synthesis of intramuscular carnosine. This systematic review evaluates the effects of beta-alanine supplementation on maximal intensity exercise in trained, young, male individuals. Six databases were searched on August 10, 2023, to identify randomized, double-blinded, placebo-controlled trials investigating the effect of chronic beta-alanine supplementation in trained male individuals with an age range of 18–40 years. Studies evaluating exercise performance through maximal or supramaximal intensity efforts falling within the 0.5–10 min duration were included. A total of 18 individual studies were analyzed, employing 18 exercise test protocols and 15 outcome measures in 331 participants. A significant (p =.01) result was observed with an overall effect size of 0.39 (95% confidence interval [CI] [0.09, 0.69]), in favor of beta-alanine supplementation versus placebo. Results indicate significant effects at 4 weeks of supplementation, effect size 0.34 (95% CI [0.02, 0.67], p =.04); 4–10 min of maximal effort, effect size 0.55 (95% CI [0.07, 1.04], p =.03); and a high beta-alanine dosage of 5.6–6.4 g per day, effect size 0.35 (95% CI [0.09, 0.62], p =.009). The results provide insights into which exercise modality will benefit the most, and which dosage protocols and durations stand to provide the greatest ergogenic effects. This may be used to inform further research, and professional or recreational training design, and optimization of supplementation strategies. [ABSTRACT FROM AUTHOR]

This study investigated the effect of oral and topical sodium bicarbonate (SB) on soccer-specific performance during simulated soccer exercise. In a block randomized, double-blind, crossover design, 10 collegiate male soccer players (stature: 181.7 ± 3.2 cm, body mass: 81.7 ± 10.5 kg) performed soccer-specific performance tests (countermovement jumps, Illinois agility, 8 × 25 m repeated sprints) throughout a 90-min soccer-specific aerobic field test (SAFT90) following 0.3 g/kg body mass SB in capsules (SB-ORAL), 0.9036 g/kg body mass PR Lotion (SB-LOTION), or placebo capsules and lotion (PLA). Soccer-specific performance tests were conducted pre-SAFT90, during half-time and post-SAFT90. Blood samples were analyzed for acid–base balance (pH; bicarbonate, HCO 3 − ) and strong ions (sodium, Na+; potassium, K+). Average sprint times were quicker for SB-ORAL than PLA during half-time (3.7%; p =.049; g =.57) and post-SAFT90 (4.9%; p =.041; g =.66). SB-ORAL increased pH and HCO 3 − prewarm-up and during half-time (p <.05), and lowered K+ during half-time (p =.035) compared with PLA. SB-LOTION increased pH (p =.019) and lowered K+ (p =.012) during half-time compared with PLA. SB-LOTION increased Na+ postexercise compared with PLA (p =.008). Repeated sprint times during simulated soccer exercise improved for SB-ORAL, which might have been mechanistically underpinned by elevated blood buffering capacity and greater regulation of strong ion concentration. Consuming SB in capsules is a more effective strategy than topical SB application for improving blood buffering capacity and repeated sprint performance throughout competitive soccer matches. [ABSTRACT FROM AUTHOR]

Purpose: To compare the training characteristics of an elite team pursuit cycling squad in the 3-month preparation phases prior to 2 successive world-record (WR) performances. Methods: Training data of 5 male track endurance cyclists (mean [SD]; age 23.4 [3.46] y; body mass 80.2 [2.74] kg; 4.5 [0.17] W·kg−1 at LT2; maximal aerobic power 6.2 [0.27] W·kg−1; maximal oxygen uptake 65.9 [2.89] mL·kg−1·min−1) were analyzed with weekly total training volume by training type and heart rate, power output, and torque intensity distributions calculated with reference to the respective WRs' performance requirements. Results: Athletes completed 805 (82.81) and 725 (68.40) min·wk–1 of training, respectively, in each season. In the second season, there was a 32% increase in total track volume, although track sessions were shorter (ie, greater frequency) in the second season. A pyramidal intensity distribution was consistent across both seasons, with 81% of training, on average, performed below LT1 power output each week, whereas 6% of training was performed above LT2. Athletes accumulated greater volume above WR team pursuit lead power (2.4% vs 0.9%) and torque (6.2% vs 3.2%) in 2019. In one athlete, mean single-leg-press peak rate of force development was 71% and 46% higher at mid- and late-phases, respectively, during the preparation period. Conclusions: These findings provide novel insights into the common and contrasting methods contributing to successive WR team pursuit performances. Greater accumulation of volume above race-specific power and torque (eg, team pursuit lead), as well as improved neuromuscular force-generating capacities, may be worthy of investigation for implementation in training programs. [ABSTRACT FROM AUTHOR]

The literature describing the effects of mental fatigue (MF) has grown tremendously. This is accompanied by identification of a host of performance-determining parameters affected by MF. MF results from prolonged cognitive effort and predominantly affects physical, technical, tactical, and perceptual–cognitive dimensions of sport, while physiological parameters (eg, heart rate, lactate) and physical aspects of maximal and supramaximal efforts are predominantly unaffected. The aim of this paper was to provide an overview of the parameters described in the literature as influenced by MF. By identifying the different parameters, we not only see how they affect the performance of athletes but also raise concerns about the potentially increased injury risk due to MF. Preliminary evidence suggests that subsequent disturbances in balance, motor skills, and decision-making processes could potentially increase the vulnerability to injury. An abundance of lab-based studies looked into the effects of MF on performance; however, many questions remain about the mechanisms of origin and neurophysiological causes of MF, and only small steps have been taken to translate this knowledge into practice. Thus, there is a need for more research into the underlying mechanisms of MF and the role of the brain, as well as more applied research with a high ecological validity that also takes into account the potential increased risk of injury due to MF. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to quantify training and match-day (MD) load during 3-, 4-, and 5-day microcycles in professional adult football, as well as to analyze the effect of the microcycle length on training load produced the day after the match (MD + 1) and the day before the match (MD − 1). Methods: The study involved 20 male professional football players whose external and internal loads were monitored for a whole season. The training exposure, total distance covered, high-speed-running distance, sprint distance (SD), individual SD above 80% of the individual maximum velocity (D > 80%), and the number of accelerations and decelerations were quantified, as well as rating of perceived exertion and session rating of perceived exertion training load. Results: Microcycle length affected most of the variables of interest: high-speed-running distance (F = 9.04, P <.01), SD (F = 13.90, P <.01), D > 80% (F = 20.25, P <.01), accelerations (F = 10.12, P <.01), and decelerations (F = 6.01, P <.01). There was an interaction effect between the training day and microcycle type for SD (F = 5.46, P <.01), D > 80% (F = 4.51, P <.01), accelerations (F = 2.24, P =.06), and decelerations (F = 3.91, P <.01). Conclusions: Coaches seem to be influenced by shorter microcycles in their training proposal, preferring sessions with a reduced muscle impact during shorter microcycles. Independent of the length of the congested fixture microcycle, the daily load seems to decrease when MD approaches. [ABSTRACT FROM AUTHOR]

The modern era of running shoes began in the 1960s with the introduction of simple polymer midsole foams, and it ended in the late 2010s with the introduction of advanced footwear technology (AFT). AFT is characterized by highly compliant, resilient, and lightweight foams with embedded, rigid, longitudinal architecture. This footwear complex improves a runner's efficiency, and it introduced a step change in running performance. Purpose: This review serves to examine the current state of knowledge around AFT—what it is and what we know about its ingredients, what benefits it confers to runners, and what may or may not mediate that benefit. We also discuss the emerging science around AFT being introduced to track-racing spikes and how it is currently regulated in sporting contexts. Conclusions: AFT has changed running as a sport. The construction of AFT is grossly understood, but the nature of the interacting elements is not. The magnitude of the enhancement of a runner's economy and performance has been characterized and modeled, but the nuanced factors that mediate those responses have not. With these knowns and unknowns, we conclude the review by providing a collection of best practices for footwear researchers, advice for runners interested in AFT, and a list of pertinent items for further investigation. [ABSTRACT FROM AUTHOR]

Purpose: To profile the training characteristics of an elite team pursuit cycling squad and assess variations in training intensity and load accumulation across the 36-week period prior to a world-record performance at the 2018 Commonwealth Games. Methods: Training data of 5 male track endurance cyclists (mean [SD]; age 21.9 [3.52] y; 4.4 [0.16] W·kg−1 at anaerobic threshold; 6.2 [0.28] W·kg−1 maximal oxygen uptake 68.7 [2.99] mL kg·min−1) were analyzed with weekly total training volume and heart rate, power output, and torque intensity distributions calculated with reference to their 3:49.804 min:s.ms performance requirements for a 4-km team pursuit. Results: Athletes completed 543 (37) h−1 of training across 436 (16) sessions. On-bike activities accounted for 69.9% of all training sessions, with participants cycling 11,246 (1139) km−1 in the training period of interest, whereas 12.7% of sessions involved gym/strength training. A pyramidal intensity distribution was evident with over 65% and 70% of training, respectively, performed at low-intensity zone heart rate and power output, whereas 5.3% and 7.7% of training was performed above anaerobic threshold. The athletes accumulated 4.4% of total training volume at, or above, their world-record team pursuit lead position torque (55 N·m). Conclusions: These data provide updated and novel insight to the power and torque demands and load accumulation contributing to world-record team pursuit performance. Although the observed pyramidal intensity distribution is common in endurance sports, the lack of shift toward a polarized intensity distribution during taper and competition peaking differs from previous research. [ABSTRACT FROM AUTHOR]

Purpose: To characterize the time structure of K1 kickboxing matches of Glory World Series (Glory) and to determine potential differences between winners and losers. Methods: Seventeen matches of Glory 2019 (17 first rounds, 13 second rounds, and 8 third rounds) were video-analyzed to quantify (1) the time expended in high- and low-intensity activity and pauses, (2) the number and pattern of attacks, and (3) the number of effective attacks. Fighters were professional male athletes (age 27.9 [2.7] y) of the middle-weight category (85 kg). The number and the pattern of attacks and the number of effective attacks were compared between winners and losers. Results: The mean times expended in high- and low-intensity activity and pauses were 234.6 (133.9) seconds, 97.4 (60.1) seconds, and 36.0 (19.9) seconds, respectively, resulting in an effort-to-pause ratio of ∼1.8:1. Compared with losers, winners presented (1) a greater number of attacks in the second round (P =.004) and entire match (P =.009), (2) a greater number of attacks containing 3 attacks in sequence in the second round (P =.001) and attacks containing >3 attacks in the third round (P =.049), and (3) a greater number of effective attacks in the second round (P =.011) and entire match (P =.008). Conclusions: The findings of the present study indicate that K1 kickboxing in Glory matches presents a ∼1.8:1 effort-to-pause ratio and that winners perform more attacks, effective attacks, and attacks in sequence. These data provide useful insights to improve the training specificity of kickboxing athletes. [ABSTRACT FROM AUTHOR]

Purpose: To compare the effects of 6-week barbell weighted-jump-squat (WJS) training with and without eccentric load reduction on explosive performance. Methods: Twenty well-trained male athletes were randomly assigned to either an experimental group (n = 10) or a control group (n = 10). Participants completed 12 WJS training sessions (6 sets of 5 repetitions of barbell back squat at 30% of 1-repetition maximum [1RM]) twice a week over a 6-week period. While the control group used 0% eccentric loading (ie, traditional WJS), the experimental group utilized a 50% eccentric loading reduction with a mechanical braking unit (ie, eccentric load set at 15% of 1RM). Performance assessments, including countermovement jump, 20-m sprint, standing long jump, and 1RM barbell back squat, were conducted both before (pretests) and after (posttests) the intervention. Results: Both the experimental group and the control group demonstrated a significant increase in countermovement-jump height (+6.4% [4.0%] vs +4.9% [5.7%]; P <.001) and peak power output (+2.3% [2.7%] vs +1.9% [5.1%]; P =.017), faster 20-m sprint times (+9.4% [4.8%] vs +9.2% [5.5%]; P <.001), longer standing long jump (+3.1% [2.5%] vs +3.0% [3.3%]; P <.001), and higher 1RM back squat (+6.4% [4.0%] vs +4.9% [5.7%]; P <.001) from pretests to posttests. However, there was no significant condition × time interaction for any variable (all P ≥.294). Conclusions: Both WJS training methods, with and without load reduction in the eccentric phase, effectively enhance explosive performance. Nevertheless, athletes in later stages of injury rehabilitation or intense training may find reducing eccentric load a more tolerable strategy for achieving similar performance gains compared with traditional isoinertial loading. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effects of transcranial direct-current stimulation (tDCS) applied over the primary motor cortex (M1) and cerebellum on balance control and shooting accuracy in elite ice hockey players. Methods: Twenty-one elite ice hockey players underwent anodal tDCS over the M1 (a-tDCSM1), anodal tDCS over the cerebellum (a-tDCSCB), concurrent dual-site anodal tDCS over the M1 and the cerebellum (a-tDCSM1+CB), and sham stimulation (tDCSSHAM). Before and after receiving tDCS (2 mA for 15 min), participants completed an ice hockey shooting-accuracy test, Pro-Kin balance test (includes stance test and proprioceptive assessment), and Y-balance test in randomized order. Results: For static balance performance, the ellipse area in the 2-legged stance with eyes open and the 1-legged stance with the dominant leg significantly improved following a-tDCSM1, a-tDCSCB, and concurrent dual-site a-tDCSM1+CB, compared with tDCSSHAM (all P <.05, Cohen d = 0.64–1.06). In dynamic balance performance, the average trace error of the proprioceptive assessment and the composite score of the Y-balance test with the dominant leg significantly improved following a-tDCSM1 and concurrent dual-site a-tDCSM1+CB (all P <.05, Cohen d = 0.77–1.00). For the ice hockey shooting-accuracy test, shooting-accuracy while standing on the unstable platform significantly increased following a-tDCSM1 (P =.010, Cohen d = 0.81) and a-tDCSCB (P =.010, Cohen d = 0.92) compared with tDCSSHAM. Conclusion: tDCS could potentially be a valuable tool in enhancing static and dynamic balance and shooting accuracy on unstable platforms in elite ice hockey players. [ABSTRACT FROM AUTHOR]

Purpose: To compare designs of training sessions applied by world-class cross-country skiers during their most successful junior and senior season. Methods: Retrospective analysis of self-reported training characteristics (ie, training form, intensity, and exercise mode) among 8 male and 7 female world-class cross-country skiers was conducted. Results: Total number of sessions (441 [71] vs 519 [34], P <.001, large effect) and mean duration (1.5 [0.1] h vs 1.7 [0.1] h, P <.001, moderate effect) increased from junior to senior age. More double-session days were performed at senior age (124 [50] vs 197 [29] d, P <.001, large). The number (310 [64] vs 393 [64], P <.001, large effect) and duration (1.3 [0.1] h vs 1.5 [0.1] h, P <.001, moderate effect) of low-intensity training sessions increased from junior to senior age. Regarding intensive training, most emphasis was put on high-intensity training sessions lasting 20 to 39 minutes with <5-minute intervals at junior age, while 40 to 59 minutes of moderate-intensity training with 5- to 9-minute intervals was predominant at senior age. More MIXED (combined moderate- and high-intensity) sessions (9 [7] vs 14 [7], P =.023, moderate effect) and longer races (0.5 [0.1] h vs 0.6 [0.1] h, P = 0.29, moderate effect) compensated for fewer high-intensity training sessions at senior age (36 [17] vs 25 [10], P =.027, moderate effect). Duration of strength-training sessions increased significantly (0.6 [0.1] vs 0.8 [0.2] h, P = 0.30, moderate effect), while other training forms remained unchanged. Conclusions: World-class cross-country skiers increased their training volume from junior to senior age primarily by more and longer low-intensity training sessions and more often training twice per day. Concurrently, the most frequent intensive sessions were modified from high- to moderate-intensity training, lasted longer, and contained longer intervals. [ABSTRACT FROM AUTHOR]

Purpose: The objective of this study was to investigate the effects of morning versus evening plyometric training (PT) on performance adaptations in male volleyball players. Methods: A total of 30 collegiate national-level young male volleyball players (age = 21.9 [2.1]; height = 186 [4.1]; body mass = 82.4 [4.6]) were randomly divided into 3 groups: morning PT (MPT), evening PT (EPT), and an active control group, each group consisting of 10 subjects. The players engaged in PT sessions twice weekly for a period of 6 weeks. The evaluation of biomotor abilities such as countermovement vertical jump, standing long jump, spike jump, block jump, 10-m sprint, T-test, sit and reach, and Y-balance test took place in the morning and evening before and after the intervention. Results: Both the MPT and EPT groups indicated significant (P <.05) improvements in all biomotor abilities from pretraining to posttraining during both the morning and evening testing sessions. Furthermore, the MPT group displayed greater adaptive responses in the vertical jump (P =.001), standing long jump (P =.023), and Y-balance test (P ≤.01) compared to the EPT group. Time-of-day fluctuations were the same between the MPT and EPT groups at the pretest. Conversely, EPT demonstrated significantly more daytime variations than MPT in the jump, sprint, and balance tests at postintervention (P <.05). Conclusion: Engaging in PT at specific times of the day has a significant impact on biomotor ability adaptations, with a focus on morning being more favorable than the evening for achieving greater gains in jump and balance performance of volleyball players. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to examine the impact of different rest periods between short sprint interval training (SSIT) trials on the physiological and performance adaptations of female volleyball players. Methods: Twenty-four trained college athletes volunteered to participate in this study and were randomly assigned to 3 SSIT groups with different work-to-rest ratios (1:2 [5-s run:10-s rest], 1:4 [5-s run:20-s rest], and 1:6 [5-s work:30-s rest]). Before and after 6-week training, physiological parameters (maximum oxygen uptake, first and second ventilatory thresholds, and peak and mean power output) and physical performance measures (ie, countermovement vertical jump, 10-m sprint, and T-test change-of-direction speed) were evaluated. Results: After the training period, all groups improved (P =.001) their sport-related performance and physiological parameters, ranging from moderate to very large effect sizes. Comparative analysis of the magnitude of training effects indicated that the 1:6 SSIT group had in a significantly greater change in countermovement vertical jump (P =.007), 10-m sprint (P =.014), peak power output (P =.019), and mean power output (P =.05) compared with 1:2 SSIT group. By contrast, the 1:2 SSIT group demonstrated significantly (P =.022) greater changes in maximum oxygen uptake than the 1:6 SSIT group. However, the change-of-direction speed and changes in first and second ventilatory thresholds were the same among the groups (P >.05). Conclusions: When performing SSIT, longer rest intervals are suitable for physical and anaerobic performance, and shorter rest periods are appropriate for enhancing the cardiorespiratory fitness of female volleyball players' performance. [ABSTRACT FROM AUTHOR]

Purpose: Maximal speed is an important physical-fitness attribute for female Australian footballers. The effects of sprint training, maximal strength, and technical training have been reported in laboratory studies. However, no study has determined the combined effect and relative contribution of these training modalities on maximal speed adaptation in situ. Therefore, the aim of this study was to determine the training factors affecting maximal speed adaptation during a preseason in subelite female Australian Rules footballers. Methods: Maximal speed during field training, predicted 1-repetition maximum (1RM) for box squat and hip thrust, and sprint biomechanics were assessed during early and late preseason (∼9 wk apart) in 15 female subelite Australian Rules Football players (age 20 [3] y). On-field training volume and intensity (total distance, high-speed running, very-high-speed running, and maximal speed) were determined using a Global Positioning System. A multivariate regression model was used to determine the factors associated with changes in maximal speed across the preseason. Results: The preseason training program had a small effect on maximal speed and large to very large effects on strength and sprint biomechanics. The multivariate regression with the greatest fit (P <.001, R2 =.939) included change in estimated 1RM box squat (β = −0.63), total distance per week (β = −0.55), and change in hip projection (β = 0.16) as factors. Multivariate regression of biomechanical factors (P =.044, R2 =.717) and maximal strength factors (P =.003, R2 =.676) were also significant. Conclusion: The development of maximal speed across a preseason is dependent on (1) total distance per week, (2) maximal strength adaptation, and (3) sprint technique adaptation in female subelite Australian rules football players. [ABSTRACT FROM AUTHOR]

Purpose: Travel fatigue impacts cognitive and physiologic systems, but its association with elite soccer match performance is unclear. In this retrospective observational study, we aimed to explore the association between travel and match outcomes in elite North American soccer. Methods: Travel data and match outcomes (team points or goals scored and conceded) and physical performance outcomes from 26 elite professional soccer teams and their players were analyzed (148 matches [team-based data] and 1252 player matches from 297 players; age 22.7 [4.5] y). Player- and match-level correlations between performance measures and both acute and cumulated travel metrics were analyzed. Results: Cumulative travel metrics were positively associated with team (travel distance [r =.20; 95% CI,.03–.25], travel time [r =.20;.06–.37], and time away [r =.20;.06–.37]) and individual player (travel distance, [r =.14;.08–.19], travel time [r =.17–.23], and time away [r =.13;.07–.18]) high-intensity running. Cumulative time away was negatively associated with team points (r = −.14; −.28 to −.001) and positively associated with goals conceded (r =.14;.01–.27); no clear association between acute travel metrics and match outcomes or physical performance was observed. Conclusions: As travel cumulated, away teams and their players ran more but for less reward (team points), although the magnitude of these associations was small. These data are exploratory and do not imply a causal relationship; however, further research should consider cumulation of travel. [ABSTRACT FROM AUTHOR]

Purpose: To describe the self-reported menstrual health, symptomatology, and perceived effects of the menstrual cycle on athletic performance for national and international Australian football (soccer) players. Methods: Players from national and domestic teams were invited to complete an online questionnaire regarding menstrual health, use of hormonal contraceptives (HCs), negative symptomatology, and perceived disruption of the menstrual cycle to performance. Descriptive statistics and binomial regressions with odds ratios (OR) were used to report the relationship of menstrual-related variables with perceived performance disruption. Results: A total of 199 players (20.9 [5.1] y) completed the questionnaire, with 18% of players reporting using HCs. One primary amenorrhea case was detected, and 26% of players reported menarche at age ≥15 years. For non-HC users, the prevalence of secondary amenorrhea was 2%, oligomenorrhea was 19%, and heavy menstrual bleeding was 11%. Ninety-seven percent of players reported experiencing physical or affective menstrual symptoms (5 [1.3] per player), and 40% of all players reported that menstrual symptoms impacted their ability to work, study, train, or compete. Furthermore, 40% of players perceived their training or performance to be disrupted by the menstrual cycle. Increasing number of menstrual symptoms (OR = 1.43; 95% CI, 1.28–1.62; P <.001), heavy menstrual bleeding (OR = 12.73; 95% CI, 3.4–82.8; P <.001), and pelvic pain (OR = 3.40; 95% CI, 1.7–7.2; P <.001) increased the likelihood of perceiving the menstrual cycle to disrupt performance. Conclusion: Heavy menstrual bleeding and HC use were low among this cohort of national and international footballers, whereas amenorrhea and oligomenorrhoea were comparable with other football populations. Nearly all players reported menstrual symptoms, and increased symptomatology was associated with greater perceived effects on performance. [ABSTRACT FROM AUTHOR]

Purpose: To assess the effect of 2 work-matched efforts of different intensities on subsequent performance in well-trained cyclists. Methods: The present study followed a randomized controlled crossover design. Twelve competitive junior cyclists volunteered to participate (age, 17 [1] y; maximum oxygen uptake, 71.0 [4.7] mL·kg−1·min−1). The power–duration relationship was assessed through 2-minute, 5-minute, and 12-minute field tests under fresh conditions (control). On subsequent days and following a randomized order, participants repeated the aforementioned tests after 2 training sessions matched for mechanical work (∼15 kJ/kg) of different intensities (ie, a moderate-intensity continuous-training [60%–70% of critical power; CP] session or a session including high-intensity intervals [3-min repetition bouts at 110%–120% of the CP interspersed by 3-min rest periods]). Results: A significantly lower power output was found in the 2-minute test after the high-intensity training session compared not only with the control condition (−8%, P <.001) but also with the moderate-intensity continuous-training session (−7%, P =.003), with no significant differences between the latter conditions. No significant differences between conditions were found for the remaining tests. As a consequence, the high-intensity training session resulted in significantly lower W′ values compared to both the control condition (−27%, P =.001) and the moderate-intensity continuous-training session (−26%, P =.012), with no differences between the 2 latter conditions and with no differences for CP. Conclusion: A session including high-intensity intermittent efforts induces a greater fatigue, particularly in short-duration efforts and W′, than a work-matched continuous-training session of moderate intensity. [ABSTRACT FROM AUTHOR]

Maximum running speed is a performance determinant in para-athletics and cerebral palsy football. Sixty international para-athletes with brain impairments completed five activity-limitation tests (standing broad jump, four bounds for distance, split jumps, 10-m speed skip, and running in place) and two criterion tests (40-m sprint and modified agility test). The same three tests (standing broad jump, four bounds for distance, and 10-m speed skip) that correlated with running performance in nondisabled runners (.67 < r < −.82; p <.05; 75% of variance) also correlated in para-athletes with brain impairments (.41 < r < −.62; p <.01; 55% of variance). Standing broad jump, four bounds for distance, split jumps, and running in place also correlated with change-of-direction speed (.43 < r < −.63; p <.01; 58% of variance). Results indicate that methods of classification for para-athletics with nondisabled runners are also valid with para-athletes with brain impairments, and new sport-specific relationships were found for assessing the performance of rapid and short sprints toward different directions, specific of a team para-sport like cerebral palsy football. [ABSTRACT FROM AUTHOR]

Purpose: To describe how high-level European sprint coaches (from 100 to 400 m) work to improve important factors associated with the quality of the holistic training process and the quality of the specific training session. Methods: A descriptive analysis was conducted using questionnaires from 31 European elite sprint coaches (ie, training athletes defined as tiers 3, 4, and 5) who participated voluntarily. Results: The coaches used traditional periodization (45%) with a 10- to 15-day tapering phase (48%) that includes a reduction in volume, maintenance of intensity, and focus on correct technical execution. In the 3 mesophases, coaches prioritized the basic development of strength and sprint work in the first phases of the season and emphasized more sprint-specific work in the competitive phase. Before sessions, adjustments were made based on factors such as psychological (77%), technical (48%), and physical (39%) parameters. In-session load management relies on a combination of objective and subjective measures (55%), in which the dialogue with athletes (65%) was regarded as the main resource. Feedback during and after sessions covers technical (54%), psychological (48%), and physical (35%) aspects. Recovery protocols after sessions mainly involve rest and professional guidance (42%). For performance assessment and testing, coaches utilize countermovement jump (52%), force–velocity profile (45%), and 30-m flying (61%) as main tools. Conclusions: European sprint coaches demonstrated a comprehensive approach to planning and management, shedding light on the multifaceted nature of their training methodologies and the diverse tools employed for athlete testing and monitoring. [ABSTRACT FROM AUTHOR]

Purpose: Loss of muscle power has a significant impact on mobility in geriatric populations, so this study sought to determine the extent and time course of performance decline in power-centric events throughout the life span via retrospective analyses of masters and elite track-and-field data. Methods: Four track-and-field events were selected based on maximal power output: the 100-m dash, long jump, high jump, and triple jump. Elite and masters athlete data were gathered from the World Masters Outdoor Championships and the International Amateur Athletic Federation World Athletics Championships (17,945 individual results). Data were analyzed by fitting individual and group results to quadratic and linear models. Results: Average age of peak performance in all events was 27.8 (0.8) years for men and 28.3 (0.8) years for women. Athlete performance decline best matched a linear model for the 5 years following peak performance (mean R2 =.68 [.20]) and for ages 35–60, but best matched a quadratic model for ages 60–90 and 35–90 (mean R2 =.75 [.12]). The average rate of decline for the masters data ages 35–60 ranged from 0.55% per year for men's 100-m dash to 1.04% per year for women's long jump. A significant age × sex interaction existed between men and women, with men declining faster throughout life in all events except the 100-m dash. Conclusions: Performance decline begins in the early 30s and is linear through middle age. This pattern of decline provides a basis for further research on power-decline pathophysiology and preventive measures starting in the 30s. [ABSTRACT FROM AUTHOR]

Purpose: This study investigated the test–retest reliability and usefulness of the foot–ankle rebound-jump test (FARJT) for measuring foot–ankle reactive strength metrics in athletes. Methods: Thirty-six highly trained, healthy athletes (5 female; 21.5 [3.9] y; 1.80 [0.10] m; 72.7 [10.4] kg) performed 8 repeated bilateral vertical foot–ankle rebound jumps on 2 testing days. Testing days were 1 week apart, and these sessions were preceded by a familiarization session. Reactive strength metrics were calculated by dividing jump height (in meters) by contact time (in seconds) for the reactive strength index (RSI) and flight time (in seconds) by contact time (in seconds) for the reactive strength ratio (RSR). The mean of 4 jumps (excluding the first and last 2 jumps) on each testing session were considered for RSI and RSR reliability and usefulness analysis. Results: We found a high reliability of the FARJT for RSI (intraclass correlation coefficient [ICC] >.90 and coefficient of variation [CV] = 12%) and RSR (ICC ≥.90 and CV = 8%). Regarding their usefulness, both RSI and RSR were rated as "marginal" in detecting the smallest worthwhile change (typical error > smallest worthwhile change) and "good" in detecting a moderate change in performance. Conclusions: The results showed that a FARJT is a highly reliable test for measuring foot–ankle reactive strength in athletes and useful for quantifying changes, for example, following a training block. However, its usefulness as an accurate daily or weekly monitoring tool in practice is questionable. [ABSTRACT FROM AUTHOR]

Purpose: To explore how the change-point method can be used to analyze complex longitudinal data and detect when meaningful changes (change points) have occurred during rehabilitation. Method: This design is a prospective single-case observational study of a football player in a professional club who sustained an acute lower-limb muscle injury during high-speed running in training. The rehabilitation program was entirely completed in the football club under the supervision of the club's medical team. Four wellness metrics and 5 running-performance metrics were collected before the injury and until the player returned to play. Results: Data were collected over 130 days. In the univariate analysis, the change points for stress, sleep, mood, and soreness were located on days 30, 47, 50, and 50, respectively. The change points for total distance, acceleration, maximum speed, deceleration, and high-speed running were located on days 32, 34, 37, 41, and 41, respectively. The multivariate analysis resulted in a single change point for the wellness metrics and running-performance metrics, on days 50 and 67, respectively. Conclusions: The univariate approach provided information regarding the sequence and time point of the change points. The multivariate approach provided a common change point for multiple metrics, information that would benefit clinicians to have a broad overview of the changes in the rehabilitation process. Clinicians may consider the change-point method to integrate and visualize data from multiple sources to evaluate athletes' progression along the return-to-sport continuum. [ABSTRACT FROM AUTHOR]