International journal of sports physiology and performance最新文献

Purpose: (1) To analyze the effects of postactivation performance enhancement (PAPE) induced by upper-limb flywheel resistance training on serve velocity and accuracy in tennis players, (2) to compare the effects of 2 different protocols (low load [LL] vs high load [HL]), and (3) to examine whether PAPE effects are influenced by tennis players' neuromuscular performance.

Methods: Fifteen young competitive tennis players completed 1 familiarization and 3 testing sessions in a randomized order. In the control session, participants performed a warm-up protocol followed by serve-velocity and -accuracy tests. The experimental sessions included 3 sets of 6 repetitions of LL (0.02 kg·m2) or HL (0.08 kg·m2) flywheel shoulder internal rotation prior to the serve-velocity and -accuracy tests. Serve velocity and accuracy were measured at 30 seconds and 3 and 6 minutes after each protocol.

Results: There were moderately significant serve-velocity differences between baseline and LL protocols at 3 (P = .009; 5.4% [5.8%]; effect size = 0.927) and 6 minutes in both LL (P = .025; 5.7% [7.2%]; effect size = 0.793) and HL (P = .026; 5.4% [6.8%]; effect size = 0.787) protocols. Serve accuracy remained stable in both protocols and recovery times. No associations were found between mechanical outcomes and percentage changes.

Conclusions: Low volume and multiple sets of shoulder internal-rotation flywheel resistance training induced serve-velocity PAPE in competitive tennis players without serve-accuracy impairment in time windows from 3 to 6 minutes. Better neuromuscular performance did not seem to favor PAPE effects.

Purpose: Previous research has primarily focused on bounce drop jump (BDJ) rather than countermovement drop jump (CDJ) in studying optimal drop heights for drop jump. This study explored the biomechanic parameters of both BDJ and CDJ and their relationship with performance across varying drop heights based on the percentage of squat-jump height (SJH).

Methods: Twenty-four college basketball athletes were recruited and divided into low- and high-strength groups. Participants performed BDJ and CDJ at 50%, 75%, 100%, 125%, 150%, and 175% of SJH. The point or zone with the largest reactive strength index (RSI) corresponds to the optimal drop height for a drop jump.

Results: Optimal drop heights were determined to be 84.7% of SJH for BDJ low strength and 84.1% of SJH for BDJ high strength, with no significant difference between groups (P = .213). For CDJ, relative optimal drop heights were 104.6% of SJH for CDJ low strength and 106.1% of SJH for CDJ high strength, also with no significant difference (P = .717). Mechanical power with RSI exhibited a coefficient close to 1 (r = .98-.99), while average propulsive force demonstrated a very strong positive correlation with RSI (r = .72-.77).

Conclusions: It is recommended that basketball athletes incorporate particular percentages of SJH into drop jump, with 75% to 100% of SJH for BDJ and 100% to 125% of SJH for CDJ, as these heights are associated with achieving an optimal RSI and mechanical power. Tailoring the inclusion of BDJ or CDJ in training should account for the specific demands of on-court positions and task objectives for basketball players.

Purpose: Confirmation bias, a cognitive phenomenon deeply ingrained in human thinking, shapes our perception of reality. It leads individuals to favor information that aligns with their preexisting beliefs while dismissing or undervaluing the contrary evidence. In sport science, where precision and evidence-based practices are critical aspects to optimize performance, confirmation bias can decisively impact decision-making processes. In this context, practitioners rely on both objective and subjective data to be interpreted to enhance athletic performance. However, confirmation bias introduces a subtle yet powerful distortion, which is difficult to control and quantify. We usually believe that our observations can justify expectations or predictions about future observations, as well as broader generalizations beyond what we have directly observed-inductive inferences. Researchers and practitioners may therefore unknowingly seek out evidence that confirms their beliefs, inadvertently overlooking alternative viewpoints and interpretations.

Conclusions: This paper explores the concept of confirmation bias in sport science, providing practical examples in the contexts of testing, training, and monitoring. By understanding how confirmation bias operates (ie, heuristic of decision making), we may develop strategies to mitigate its effects and promote more accurate and effective decision making in sport science (eg, performance).

Purpose: Although women's futsal has experienced great growth recently, few studies have analyzed the physical profiles of female futsal players. The objectives of this study were to determine the physical and anthropometric characteristics in elite women's futsal using laboratory and field tests and to analyze the differences between the different playing positions.

Methods: Forty-one female futsal players from the second division of the Spanish league (age 22.69 [4.76] y; body height 161.28 [6.03] cm; body mass 62.20 [10.34] kg) were evaluated for body composition with dual-energy X-ray absortiometry anthropometrically, lower-body power using a force platform (countermovement jump, squat jump, and drop jump), linear speed (5, 10, 15, and 25 m), changes of direction (505 modified, V-Cut, and L-Run), and repeated-sprint ability measured through photoelectric cells.

Results: The results reveal that there are no significant differences between the physical profiles of players depending on playing position. Despite this, wingers seem to have the best physical profiles, and goalkeepers have the highest body mass index (26.9 [4.48] vs 23.3 [2.82]; P = .069) and fat percentage (31.9 [7.81] vs 29.96 [6.08]; P = .101), but they present very similar values to the other positions in all other tests performed, except for repeated-sprint ability (4.64 [0.45]; P = .009).

Conclusion: Relevant descriptive data were presented to provide useful information for coaches to optimize their training programs, reporting that playing position does not identify different physical profiles in elite female futsal players.

Background: Practices to routinely monitor athletes are rapidly changing. With the concurrent exponential rise in wearable technologies and advanced data analysis, tracking training exposures and responses is widespread and more frequent in the athlete-coach decision-making process. Within this scenario, the concept of invisible monitoring emerged, which was initially vaguely defined as testing athletes without testing them. Despite sound practical applications and benefits (eg, reduced burden on player staff and more frequent measurement), a clear lack of constitutive definition has led to multiple cleavages in both research and practice, including ethical concerns.

Purpose: The purpose of this study is to (1) extend the current conceptualization of invisible monitoring by considering subdimensions of the concept and (2) its data-related and ethical challenges and (3) provide practical considerations to implement invisible monitoring. Monitoring burden (degree of obtrusion and frequency of measurement) and the number of constructs a single measurement tool can assess have been proposed as subdimensions of the concept of invisible monitoring. Challenges include the governance and analysis of data required to make estimates, validity and reliability of an invisible monitoring measure, and communication to athletes.

Conclusions: This commentary presents a first attempt to conceptualize invisible monitoring in the context of elite sport and provide subdimensions of the concept that can be used to classify choices of measurement tools. A consensus is required from both researchers and practitioners regarding its definition and operationalization to optimize current monitoring services to elite athletes.

Background: The Los Angeles 2028 Olympics will mark the debut of squash, a high-intensity sport characterized by repeated efforts, posing potential thermoregulatory challenges. The demanding nature of squash results in substantial metabolic heat production, with consequential heat strain exacerbated by the indoor environment of squash courts, where low to moderate evaporative potential limits effective cooling. Players often experience increased body-heat storage and thermal strain, with muscle cramps (an early warning sign of more severe heat-related illnesses) commonly observed during tournaments. Despite these challenges, there are limited data on the thermoregulatory responses of elite squash players during match play.

Purpose: We discuss the thermoregulatory challenges faced by squash players and highlight key areas for research. Additionally, practical guidelines are provided for practitioners preparing squash players for the Los Angeles 2028 Olympics.

Evidence: Preliminary findings from international squash tournaments reveal that elite players endure significant physiological strain, with core temperatures rising to 39.0 °C to 40.1 °C, despite matches being played in mild wet-bulb globe temperatures of 19.4 °C (0.9 °C). Sustained heart rates exceeding 90% of maximal heart rate further compound this thermal strain. However, research on how thermal strain affects squash-specific fitness, recovery, and stroke mechanics are lacking. Such information is crucial for evaluating the need and effectiveness of tailored mitigation strategies such as heat training/exposures and precooling and midcooling during warm-up and match play.

Conclusion: Systematic research into the thermal demands of squash and their impact on fitness and skills is needed. These insights can inform evidence-based strategies to safeguard athlete well-being and optimize performance at Los Angeles 2028.

Background: Mental fatigue (MF) is a psychobiological state that could negatively impact physical and cognitive performance, although the extent of this impact remains controversial. While laboratory studies have provided valuable insights into the acute effects of MF, their ecological validity in real-world sport settings remains limited. Recent research indicates that MF can naturally arise during sport activities, leading to chronic effects on endurance and perceptual-cognitive skills. These effects may persist beyond individual sessions, potentially increasing the risk of injury due to their cumulative nature.

Purpose: This commentary aims to guide future research by emphasizing the need to investigate the natural occurrence and chronic effects of MF in applied sport settings.

Conclusions: Understanding how MF develops and manifests in real-world settings, particularly individual differences in perception and response, is crucial for creating more effective management strategies. Addressing these factors will enable better support for athletes who may experience prolonged periods of MF that could affect their training and competitive performance. Future research should prioritize studying MF in natural sport settings to enhance the ecological validity of findings. By focusing on the chronic and cumulative nature of MF, as well as individual variability, researchers can develop more tailored and effective strategies for managing MF. This research will not only bridge the gap between laboratory studies and real-world applications but also contribute to more precise monitoring and intervention techniques. Ultimately, these advancements will improve athletes' ability to maintain peak performance and reduce the risk of injury, thereby enhancing overall athletic well-being.

Purpose: The assessment of lactate threshold (LT) and its relationship to open-water (OW) performance is crucial. This study aimed (1) to analyze LT in world-class OW swimmers, (2) to compare swimming speed at LT (SSLT) and 4 mmol·L-1 of blood lactate concentration ([La-]; SS4), and (3) to examine the relationships between SSLT and swimming performance.

Methods: Twenty world-class and elite (11 male, 26.4 [3.0] y; 9 female, 25.8 [3.6] y) OW swimmers voluntarily participated. A total of 46 (29 male and 17 female) intermittent incremental tests (7 × 400 m) conducted in a 50-m pool were analyzed. Seasonal best performances on 400-, 800-, and 1500-m and 10-km OW swimming events were obtained.

Results: The SSLT was 1.62 (0.02) (3.8 [1.0] mmol·L-1) and 1.46 (0.04) m·s-1 (3.0 [0.7] mmol·L-1) in males and females, respectively, which corresponded to 97% of the peak speed reached in the tests. There were no differences (P = .148) between SSLT and SS4 in males; however, SSLT was lower (P = .019) than SS4 in females. The SSLT was negatively correlated with swimming performance, with the exception of 10-km OW and 400-m times in males and females, respectively.

Conclusions: World-class and elite OW swimmers exhibited a greatly developed aerobic capacity with LT close to their maximum speed. The SS4 could be used as an approximation to SSLT in males but overestimates true aerobic capacity in females. LT is a useful tool for assessing performance, as OW swimmers with higher SSLT showed better swimming performance.