International journal of sports physiology and performance最新文献

Purpose: To describe the race workload and strength profile of MotoGP World Champion riders and explore potential differences between categories: MotoGP, Moto2, and Moto3.

Methods: The race workload of the 2023 championship was analyzed, calculating the average length of the Grand Prix (in meters), duration (in minutes), average speed (in km·h-1), top speed (in km·h-1), laps (number), curves (number), and curve density (in n·min-1) in the 3 categories. Thirty-two riders (6 MotoGP, 11 Moto2, and 15 Moto3) were assessed: hand grip (in newtons), bench press (in newtons), countermovement jump (CMJ), and squat jump (in CMJ: dynamic strength index; in CMJ and squat jump: height [in meters], peak power [in N·kg-1], force [in N·kg-1], impulse [in N·s]), and isometric hip adduction and abduction (in newtons). Differences between categories were analyzed using a Kruskal-Wallis test. The Mann-Whitney test was used to compare values between them.

Results: All workload parameters (except curve density) were higher (P < .001) in MotoGP versus Moto2 and Moto3. MotoGP riders had more hand-grip force in their left (P = .009) and right (P = .018) forearms than other categories' riders. Moto3 riders were smaller (P < .001) and lighter (P = .002) and showed lower impulse in CMJ (P < .001) and squat jump (P = .001) versus Moto2 and MotoGP. Moto2 riders had higher left (P = .004) and right (P = .005) absolute hip abduction than Moto3.

Conclusions: The Grand Prix race workload was significantly higher in MotoGP. There were differences between categories in hand grip, jump impulse, and abduction. This suggests the need to implement rider's strength evaluations.

Purpose: This study aimed to investigate whether maximal oxygen uptake, strength, and power parameters are influenced by the timing of oral contraceptive (OC) pill intake-specifically 1 versus 24 hours before testing.

Methods: Twenty-nine trained young females using monophasic second-generation OCs participated in a crossover design study. Following test familiarization, participants completed a physical test protocol 2 times during the active OC pill phase: once 1 hour after OC intake and another at 24 hours after OC intake, in randomized order. The protocol assessed balance, push-up endurance, agility, handgrip strength, jump height, flexibility, and maximal oxygen uptake. Psychological well-being was evaluated using a questionnaire prior to testing. Test conditions were standardized for time of the day, energy intake, and exercise within 24 hours preceding the test. Hormone levels were analyzed in serum and saliva collected at the time of testing in a subsample.

Results: Balance stand time was shorter (median difference: 1 s [interquartile range: -3.3, 0.7], P = .021) and handgrip strength higher (mean: 0.8 [2.1] kg, P = .044) when the OC was taken 1 hour before testing compared with 24 hours before testing. No significant differences were observed for push-up endurance, agility, jump height, flexibility, and maximal oxygen uptake between the 2 test days.

Conclusions: The findings suggest that the timing of OC intake may acutely influence specific physiological parameters related to physical performance, such as balance stand and handgrip strength. Future studies involving OC users should consider standardizing OC intake to account for potential hormonal effects on performance outcomes.

Purpose: Mental fatigue (MF) is increasingly implicated in elite sports, yet its characteristics and impact in real-world fencing, a highly perceptual-cognitive demanding domain, are underexplored.

Methods: A 4-week single-blind, longitudinal study monitored 31 (7 épée, 13 foil, and 11 sabre; 15 females) elite fencers' daily MF across training and competition phases before, during, and after a national championship. Subjective MF on a visual analog scale and reaction time (from 3-min Psychomotor Vigilance Test) were measured daily in the morning (baseline) and after training or competition. Self-reported individualized training variables (session rating of perceived exertion, duration, and detailed training workload demands) were collected posttraining. One-way repeated-measures analyses of variance assessed daily MF on a visual analog scale and reaction-time changes across phases. Linear mixed-effect models examined the impact of training load and specific training workloads on MF.

Results: Analysis of 93 match days and 440 training days revealed that MF on a visual analog scale increased after fencing activities compared with baseline, peaking on match days (+19.34 AU, P < .001), which aligned with an impaired reaction time (+76.43 milliseconds, P < .01). On training days, overall training load (estimate = 0.02), as well as the contributions of tactical (estimate = 0.26) and physical (estimate = 0.12) workload demands, positively predicted the MF increase (all P < .001), whereas environmental demand (estimate = -0.13, P = .022) mitigated the MF elevation.

Conclusions: The study highlights the prevalence of MF in elite fencers and its subsequent impact on reaction performance on competition days. The association with specific training structures provides insights for coaches and athletes to actively manage MF and optimize performance throughout a season.

Purpose: This exploratory study aimed to determine and compare the external and internal training and racing load characteristics of female professional cyclists during "highly successful" and "less successful" seasons.

Methods: Forty-three seasons of 14 World Tour cyclists (seasons: 3 [1] per cyclist, age: 24 [4] y) over a 7-year period were analyzed (9.036 training and 1.974 races). Based on the ProCyclingStats points per race, cycling seasons were classified as "highly successful" (≥5 points per race) or as "less successful" (<5 points per race). External and internal load characteristics and intensity distributions were determined and compared using a multilevel random intercept model followed by pairwise comparison.

Results: Most external load characteristics (such as distance, duration, and kilojoules burned) were higher during "highly successful" seasons (P < .01), while the overall mean power outputs were similar. During "highly successful" seasons, cyclists were able to train more in power zones 1 and 2 (P < .05), while cyclists during less successful seasons were spending relatively more time in zone 5 during races (P < .01). In contrast to external load characteristics, no differences were found in internal load characteristics between "highly successful" and "less successful" seasons.

Conclusion: Professional female cyclists in "highly successful" seasons were able to train more (volume) than during "less successful" seasons. In addition, the relative intensity of training sessions and races was lower during "highly" than "less" successful seasons. These findings highlight the importance of high-volume low-intensity training in female professional cyclists, which may contribute to better durability capacity in races.

Purpose: Focus-of-attention (FOA) research typically supports an external focus (EF) over internal focus (IF) for motor learning and performance. However, task-specific factors such as athletes' techniques and training goals may influence FOA efficacy. This study compared the effects of FOA strategies-idiosyncratic core component (ICC), EF, and IF-on explosive isometric back squats (EIBS) and squat jumps (SJ) in skilled basketball athletes.

Methods: Eighteen elite basketball players performed 3 trials of EIBS and SJ under each FOA condition. Force peak (Fp), impulse (Im), and mean rate of force development (mRFD) were assessed using a force plate. Rating of perceived exertion (RPE) and perceived emotional state were also recorded.

Results: ICC significantly enhanced mRFD during EIBS compared with EF (P = .014) and IF (P = .015), with no difference between EF and IF. FOA did not significantly affect Fp or Im during EIBS. In SJ, FOA strategies had no significant effects on mRFD, Fp, or Im. RPE and perceived emotional state scores remained consistent across conditions.

Conclusions: ICC improved explosive strength during EIBS, highlighting the benefit of individualized FOA strategies for tasks >200 milliseconds in duration. However, FOA showed limited impact on SJ performance metrics, possibly due to the task's shorter duration. Strength and conditioning coaches should tailor FOA strategies to specific tasks and outcomes, using ICC to optimize explosive strength in longer-duration tasks.

Purpose: Despite the increasing body of literature on badminton, no data exist concerning the energy cost of badminton movement, known as "footwork." This study introduces a novel experimental approach to assessing the energy cost of footwork by applying established metabolic measurement techniques to badminton-specific movement patterns for the first time. In addition, it aims to verify whether differences exist between 2 different movement combinations.

Methods: Seven male and 7 female badminton athletes (age 19 [4] y; body mass 64.9 [8.4] kg; height 1.72 [0.08] m; V˙O2peak 55.5 [10.3] mL·kg-1·min-1) completed 2 sets of 12 repetitions of 4 all-out preplanned footwork exercises with 30 seconds of passive recovery, using 2 types of steps (side step and running step). During exercises, respiratory data, blood lactate concentration, and net energy cost (CnetFW, J·kg-1·m-1) were determined, along with total exercise duration and average speed.

Results: CnetFW was 19.59 (4.46) for side step and 20.38 (4.52) J·kg-1·m-1 for running step. No significant differences in metabolic data, total exercise duration, or average speed were observed (P < .05). CnetFW data showed a positive linear correlation between energy cost and footwork speed (r = .62; r2 = .39; P = .0009).

Conclusions: CnetFW increases with speed, but there is no significant difference between the 2 types of footwork. Players and coaches can choose the most appropriate step combinations based on individual characteristics and specific game requirements.

Purpose: Topical menthol application improves thermal perception and enhances performance but reduces sweat production in hot environments. In the aquatic environment, where sweat evaporation is of limited thermoregulatory benefit (ie, minimal evaporation) and leads to dehydration and cardiovascular strain, downregulating thermoregulatory sweating may have little consequence. However, it may preserve hydration status and improve subsequent performance, especially in air (ie, after first transition in triathlon); we tested this hypothesis.

Method: Eight trained triathletes (age 36 [5] y; height 1.77 [0.1] m; mass 73.9 [8.0] kg) completed 2 experimental conditions with prior whole-body application of menthol GEL (40 g, 3.5% menthol) contrasted to NO-GEL. The protocol comprised 30 minutes of swimming (at 85% of 400-m personal best) in tropical water (29 °C) followed by a 20-km self-paced cycling time trial. Measures were deep body temperature (gastrointestinal pill), skin temperature, sweat production, rating of perceived exertion, thermal sensation, and thermal comfort. Paired t test and analysis of variance compared the data (.05 alpha level).

Results: Wet-bulb globe temperature equated to "red flag" conditions-heat-injury potential for all participants. Terminal gastrointestinal temperature was 38.8 °C (0.3 °C) and 38.8 °C (0.7 °C) and time-trial performance was 39:36 (04:31) and 40:53 (05:53) minutes in the GEL and NO-GEL conditions, respectively (P = .340; 95% CI, -222 to 88 s; d = -0.22). Sweat production increased in the GEL condition (1140 [257] mL) compared to the NO-GEL condition (961 [202] mL) (t = 2.482, P = .042; 95% CI, 08 to 349 mL; d = 0.77).

Conclusion: Menthol improved perception but increased thermoregulatory sweating and did not enhance performance (partial hypothesis support).

Purpose: Preseason in football is crucial for optimizing physical fitness, team cohesion, and tactical readiness. This study investigated the effects of 2 distinct preseason training environments-mild altitude with cooler conditions and sea level with higher heat and humidity-on cardiovascular fitness, readiness, and match intensity in professional football players.

Methods: Fifteen elite male players were monitored during 2 consecutive preseasons (2023-24 and 2024-25), with external- and internal-load parameters assessed via global positioning systems and heart-rate (HR) tracking systems. Cardiovascular fitness was evaluated using HR responses during submaximal running tests (HRex) and machine-learning models (Δ HR), and readiness was assessed through vertical stiffness (Kvert) and locomotor efficiency (Δ PL), also using machine-learning approaches.

Results: Multilevel regression analysis indicated that general fitness, represented by HRex, improved independently of environmental conditions and was primarily influenced by cumulative training load (γ = -0.045, P = .004). However, specific fitness (Δ HR) improved more significantly under higher temperatures (γ = 8.188, P = .009). Increased heat exposure reduced readiness levels, as reflected by declines in Kvert and Δ PL by the end of the sea-level preseason. Match intensity showed no significant differences between environments.

Conclusions: Sea-level preseason training environments appear to promote faster specific fitness gains, likely due to cardiovascular adaptations. We hypothesize that these adaptations could be related to the effects of heat exposure, such as plasma volume expansion. However, it also results in lower readiness levels, affecting vertical stiffness and locomotor efficiency. These findings provide valuable insights for designing preseason programs to balance cardiovascular fitness gains and fatigue mitigation.