International journal of sports physiology and performance最新文献

Purpose: Recent rule changes in team handball have increased the relevance of sprinting and acceleration for performance outcomes. This study aimed to evaluate the acceleration-velocity profiles of elite female players during the Final Weekend of the Women's EURO 2024.

Methods: Sixty-four players from the 4 finalist teams (19 wings, 33 backcourts, and 12 line players) were monitored using a validated Local Positioning System. Data were processed in Python, using dual-pass Butterworth filtering to refine the signal and determine each player's maximum velocity. Peak acceleration and distance covered at speeds exceeding 4 m/s were calculated, and all running trajectories exceeding 90% of each player's individual maximum velocity were considered for the final analysis, with a 3-second buffer added before and after each event for descriptive purposes. Results were grouped by playing position and 2 game phases (fast breaks or defensive transitions).

Results: Wings covered significantly greater distances and exhibited higher peak speeds and accelerations than backcourt and line players (P > .001). No significant differences in intensity metrics were found between offensive and defensive transitions; however, the trajectory analysis revealed that maximal-intensity actions occurred nearly twice as often during defensive transitions.

Conclusion: In-competition assessment of individual acceleration-velocity profiles provides valuable insights for coaches seeking to manage high-speed running loads across training sessions or microcycles. Position-specific data may also help design training tasks that more accurately replicate real match demands.

Purpose: High-intensity interval training (HIIT) and sprint interval training (SIT) can improve physiological (eg, maximal oxygen uptake [V˙O2max]) and locomotor (eg, maximal aerobic speed, MAS; maximal sprinting speed, MSS) variables. However, the influence of an athlete's locomotor profile on training adaptations to HIIT and SIT remains unclear. We aimed to (1) compare physiological and locomotor adaptations to HIIT and SIT and (2) assess how locomotor profiles affect these adaptations.

Methods: Twenty-seven trained male and female runners (27.7 [7.5] y; n = 12 women) completed 6 weeks of HIIT (4-6 × 4 min @90%-95% MAS) or SIT (6-10 × 20-s all-out sprints), performed twice weekly. Pretest and posttests included 40-m sprinting (MSS) and incremental treadmill tests (V˙O2max, MAS, lactate thresholds [eg, v4mmo]). Anaerobic speed reserve was calculated as MSS minus MAS and speed reserve ratio as MSS divided by MAS. Linear mixed models and moderation analyses were performed.

Results: Both HIIT and SIT significantly improved MAS (P ≤ .03). While only SIT enhanced MSS (interaction: P < .01), HIIT increased v4mmol (P < .01). In both groups, speed types (ie, higher speed reserve ratio and anaerobic speed reserve) showed greater MAS (P < .01) and v4mmol increases (P < .05) than endurance types (ie, lower speed reserve ratio and anaerobic speed reserve). Within the SIT group, endurance types improved MSS (P < .01) and V˙O2max more, while speed types increased V˙O2max more with HIIT (interaction: P ≤ .03).

Conclusion: HIIT and SIT improve endurance outcomes in trained runners. Adaptations vary depending on locomotor profile, with speed types responding better to HIIT and endurance types benefiting more from SIT. Accordingly, individualizing training by locomotor profile may optimize outcomes.

Purpose: The purpose of this research was to investigate the impact of an 8-week depth jump (DJ) plyometric training using individualized (I-DJT) or traditional DJ training (T-DJT) methods on the physical performance adaptations of male volleyball players.

Methods: Twenty-four trained male volleyball players volunteered to participate in the study and were randomly allocated to 3 groups: I-DJT (n = 8), T-DJT (n = 8), and an active control group (n = 8). The T-DJT group underwent an 8-week DJ training from a 45-cm box height, while the I-DJT group integrated DJ training from a personalized box height determined by their power production during the reactive strength index test. Prior to and after the 8-week program, various physical performance variables such as countermovement vertical jump, spike jump, block jump, 10-m sprint, agility T-test, lower-body maximal strength, and the Wingate anaerobic power test were assessed.

Results: After the 8-week training intervention, both training groups observed significant improvements (P = .001) in physical performance, with effect sizes ranging from small to large. A significant group by time interaction (P < .05) indicated that the I-DJT group experienced greater adaptive changes in all physical performance compared with the T-DJT group after the 8-week training period (except block jump). Furthermore, the I-DJT group displayed lower intersubject variability and individual residuals in percent change compared with the T-DJT group.

Conclusion: Individualized DJ training appears to be an effective strategy for enhancing physical performance in volleyball players. By facilitating relatively consistent loading across the training period, it may help to minimize interindividual variability in adaptive outcomes.

Purpose: This study evaluated how lower-limb explosive strength relates to 15-m speed-climbing performance by combining jump kinetics, muscle morphology, and surface electromyography (sEMG).

Methods: Fifteen Chinese speed climbers (10 men, 5 women) who had placed within the top 3-6 at national-level competitions underwent ultrasound imaging of the rectus femoris (RF) and medial gastrocnemius (GM), and then, in random order, completed unilateral and bilateral squat jumps, countermovement jumps, and a 15-m speed-climbing test. Force plate recorded peak force (Fpeak) and rate of force development (RFD); sEMG yielded integrated EMG for the main lower-limb muscles.

Results: Unilateral and bilateral squat jumps/countermovement jumps Fpeak correlated with climbing speed (r = .63-.77, P = .004-.029). Both right-leg (r = .62, P = .033) and bilateral (r = .62, P = .03) countermovement jumps RFD correlated with speed. Bilateral-jump Fpeak correlated with right-side RF thickness (r = .59-.81, P = .001-.043), whereas bilateral RFD with both GM thickness and fascicle length (r = .58-.63, P = .029-.049). During climbing, speed negatively correlated with left-side RF integrated EMG (r = -.6, P = .041) and positively with bilateral GM integrated EMG (r = .59-.64, P = .026-.045; other muscles P > .05).

Conclusions: Right-leg RF thickness appears to drive Fpeak, and thus climbing speed, whereas GM thickness and fascicle length primarily influence RFD. A contrasting activation pattern (lower RF, higher GM engagement) likely underlies these morphology-performance links. Coaches can target maximal-strength and plyometric training to enlarge the right RF and GM and lengthen GM fascicles, potentially improving speed-climbing performance.

Purpose: It is possible that, under certain circumstances and with appropriate caveats, the highest rate of carbon dioxide output during exercise (V˙CO2peak) could be valuable in the physiological evaluation of athletes. The aim of this study was to compare a ramp incremental test, a 30-second Wingate test, and a 3-minute all-out test to identify the protocol that provides the highest V˙CO2peak value.

Methods: Twelve physically active males completed the 3 tests in random order on a cycle ergometer. Breath-by-breath cardiorespiratory responses were measured before the onset of exercise, throughout the exercise sessions, and during the first 15 minutes of recovery to determine the highest 15-second mean V˙CO2 responses. Capillary blood lactate concentration ([lactate]) was assessed at rest and postexercise to determine peak Δ [lactate].

Results: The V˙CO2peak was significantly greater in the 3-minute all-out test (64 [5] mL·min-1·kg-1) than in both the incremental exercise test (57 [5] mL·min-1·kg-1; P < .001) and the Wingate test (53 [8] mL·min-1·kg-1; P < .001). Peak Δ [lactate] was higher in the 3-minute all-out test (15.9 [2.7] mM) than the ramp test (11.9 [2.6] mM; P < .05) but did not differ from the Wingate test (13.3 [2.6] mM; P > .05).

Conclusion: These findings indicate that the V˙CO2peak was approximately 12% to 21% higher in the 3-minute all-out test compared with the incremental exercise test and the Wingate test. Future considerations of a possible role for V˙CO2peak in the physiological evaluation of athletes should ensure that an appropriate test protocol, such as the 3-minute all-out test, is used for its assessment.

Purpose: To examine the relationship between well-being and match performance in elite team handball.

Methods: Eighteen male handball players competing in the first German national league were investigated over an entire season (September 2023 to June 2024). On matchdays, well-being was assessed in the morning with a customized, nonvalidated questionnaire, consisting of three 5-point Likert-type items ("physical condition," "mental freshness and energy level," and "sleep and recovery"). Team performance was evaluated based on the points scored in each match. Individual performance was assessed using a novel approach with 4 data aggregates of positive and negative offense and defense playing actions, on which the Handball Performance Index (version 2.0; official individual match performance metric in the Handball-Bundesliga) is based. Cumulative link models for ordinal regression and linear mixed-effects models were used to analyze the relationship between well-being, match type (home vs away), and both team and individual performance.

Results: "Sleep and recovery" ratings were lower prior to away matches (p < .001). Interaction effects revealed that physical and mental well-being influenced match outcomes ("physical condition" × "match type": P = .019, "mental freshness and energy level" × "match type": P = .001), with a weaker effect in away matches. No significant effects were observed on individual performance metrics.

Conclusions: This study is the first to investigate the complex relationship between athlete well-being, contextual factors (home vs away matches), and performance in elite team handball. However, it is important to consider the study's limitations regarding validity, applicability, and transferability.

Purpose: In preparation for the reduced 1500-m-rowing racing distance at the Los Angeles 2028 Olympic Games, we compared performance between maximal 2000-m (TT2000) and 1500-m (TT1500) ergometer time trials and evaluated the predictive accuracy of a linear critical speed (CS) model in elite rowers.

Methods: Thirty-four elite under-23 rowers (12 female, 22 male) completed TT2000, TT1500, and 500-m (TT500) maximal ergometer time trials on separate days. Performance differences between TT2000 and TT1500 were assessed using linear mixed modeling. Completion times from TT2000 and TT500 were used in a CS model to predict TT1500 time.

Results: Compared with TT2000, mean power output was 4.8% higher in males and 4.4% higher in females during TT1500, with a 26% reduction in completion time across both groups. The CS model using TT500 and TT2000 accurately predicted TT1500 time for both sexes, with a mean absolute error of <1 second, a standard error of estimate of 2.8 seconds, and a coefficient of variation of 0.5%. A near-perfect correlation existed between actual and predicted TT1500 times (R = .99).

Conclusions: This simple CS model, based on standard tests, allows practitioners to track 1500-m performance progression without disrupting preparation for 2000-m events, which remain central to international competition throughout the Los Angeles 2028 Olympic Games quadrennial. Performance times in TT1500 indicate that elite rowers likely require further specific preparation to optimize performance over the reduced Olympic racing distance.

Purpose: Athletes frequently experience sleep disturbances due to training intensity, competitive pressure, and travel. While sexual activity, particularly achieving orgasm, is linked with improved sleep through hormonal mechanisms in general populations, this relationship remains unexplored in athletes, whose sleep and recovery needs are unique. This cross-sectional study primarily aimed to examine competitive athletes' perceptions regarding how sexual activity (partnered intercourse and masturbation, with or without orgasm) influences sleep quality, latency, and sport performance and explore differences by sex and sport discipline (individual vs team).

Methods: In this cross-sectional descriptive study, 164 competitive athletes (males = 115, females = 49; age 18-40 y) from Italian sport federations completed a structured survey assessing sexual behavior, orgasm frequency, sleep parameters, and perceived athletic impact. Statistical analysis included chi-square, Fisher exact, and t tests with significance at P < .05.

Results: A majority reported that orgasmic sexual activity significantly improved sleep quality (partnered sex: 67.7%, masturbation: 49.1%) and latency (partnered sex: 58.4%, masturbation: 46.9%). Partnered sex appeared slightly more beneficial, but the difference was not statistically significant (quality: P = .810, latency: P = .996). Significant sex differences emerged in orgasm consistency during partnered sex (men: 77.8%, women: 30.0%; P < .001) and masturbation (men: 99.1%, women: 83.3%; P < .001). No sex or sport-discipline differences were identified regarding perceived sleep benefits or performance impact; most athletes (≥50%) perceived no negative effects on training or competition.

Conclusion: Competitive athletes perceive sexual activity with orgasm as beneficial for sleep and neutral regarding athletic performance, challenging conventional abstinence recommendations. Practitioners should adopt individualized, evidence-based strategies when advising athletes on sexual behavior in relation to sleep and performance.

Purpose: Lifting straps (LS) are popular tools used by resistance-training (RT) practitioners with the intention of improving exercise performance. This tool is worn around the wrist to enhance grip on the barbell or other RT equipment and potentially decrease grip limitation throughout the exercise-a limitation that is usually reported by practitioners, especially during deadlifts, weightlifting movements, and pulling exercises. However, this knowledge remains mostly based on common experiential beliefs. Thus, this narrative review aims to highlight the current knowledge on the impact of LS in RT, focusing on physiological and biomechanical effects, exercise performance, chronic training adaptations, and safety concerns, and also to expose the existing literature gaps and distinguish between evidence-based findings and empirical assumptions.

Conclusion: Evidence suggests that LS can enhance maximal strength and grip perception. However, for pulling/back exercises, no consistent effects have been observed. In addition, LS may increase mechanical work in the deadlift, but contrary to common belief, they appear not to contribute to increased muscle recruitment. Furthermore, no scientific evidence supports the chronic effects of LS usage in training; it is still a hypothesis. Finally, this review offers future research insights to assist sport scientists in designing and conducting more comprehensive investigations on this topic, ultimately enhancing the understanding and application of LS in RT.

Purpose: To assess total, weekly, and session rating of perceived exertion (sRPE) training load (TL), identify factors influencing sRPE-TL, and analyze interplayer, individual relative-to-team, and intraplayer variability in elite youth female footballers.

Methods: All outfield players (age 13.7 [0.5] y) from the U14 (under 14 y of age) team of a Spanish Women's First Division academy were monitored over a 19-week competitive period. Players reported sRPE after each training session and match. TL was calculated as sRPE × session duration. Individual- and team-level analyses were performed.

Results: Players completed 95% (4%) of sessions. Total and weekly team sRPE-TL averaged 19,717 (1708) and 1200 (104) AU (arbitrary units), respectively. Playing position had no significant effect (P > .05), whereas training day significantly influenced session TL (P < .001), with matches showing substantially lower TL than training sessions (Cohen d: 2.85-4.34). Interplayer variability was small to moderate (coefficient of variation 7%-14%). Differences between individual and team means ranged from -26% to +25%, trivial to very large. Intraplayer variability was moderate to very large (coefficient of variation 10%-53%), with session-level variability classified as very large for all players. The interaction between individual-team difference and intraplayer variability was analyzed.

Conclusions: Despite consistent team-level TL, marked individual differences emerged. Two individual TL profiles were identified: (1) mean-aligned versus mean-divergent and (2) stable versus unstable. Combining both dimensions enhances individual TL profiling and supports tailored training strategies. These findings emphasize the need to move beyond team averages to ensure appropriate monitoring and individualized development in elite youth female football.