European journal of sport science最新文献

Little is known about early tendinopathy in elite athletes. This study aimed to investigate changes in clinical and ultrasonography outcomes over 1 year and assess the prognostic values of these outcomes at baseline with respect to tendinopathy progression. Sixty-two elite athletes (24 ± 5 years) with early phase (symptom duration < three months) Achilles or patellar tendinopathy (AT and PT) were examined at baseline and after one year. Pain-guided activity modification was the only intervention. Clinical outcomes were assessed using Victorian Institute of Sports Assessment questionnaires (VISA) for function and symptoms, pain scores (1–10 numerical rating scale (NRS)) and ultrasound tendon morphology (thickness, echogenicity and power Doppler (PD) flow area). A linear mixed-effects model analysed changes from baseline to 1 year. Athletes showed clinical improvements in VISA-Achilles (baseline: 66 ± 5 vs. one-year: 87 ± 2, 95% CI: 13–30, p < 0.0001 and effect size d = 3.8), VISA-Patella (baseline: 69 ± 3 vs. one-year: 86 ± 1, 95% CI: 10–26, p < 0.0001 and effect size d = 3.6) scores and most NRS pain scores (≥ 2 points). Tendinopathic Achilles tendons' peritendinous thickness was reduced (−0.79 mm, p = 0.0188 and effect size d = 0.5), whereas patellar tendons remained enlarged. For both AT and PT, lower baseline PD was associated with a greater reduction in thickness over time (p < 0.001) and higher baseline VISA scores were linked to greater increases in echo intensity over time (p = 0.0363). In conclusion, elite athletes with early phase AT and PT showed clinical improvement over 1 year, with morphological changes in tendinopathic Achilles tendons only. Lower baseline PD and better initial VISA scores represent a better prognosis for tendinopathy morphology and symptoms.

The aim of this study was to assess the effects of oxygen availability (normoxia vs. hypoxia), muscle mass and exercise type on pulse oxygen saturation, and quadriceps muscle oxygenation during repeated sprint exercises. Sixteen healthy participants completed 5 $$ 12 s sprints (21 s rest). This sprint-like exercise was performed under two environmental conditions (normoxia: FiO₂ = 21%; systemic hypoxia: FiO₂ = 13%) and for three exercise modalities: unilateral knee extensions (KE) involving the right leg extensors (UNI), bilateral KE involving both legs extensors (BIL), and bilateral leg cycling (CYC). Measurements included power output, pulse oxygen saturation (SpO₂), and vastus lateralis oxygenation (delta in tissue saturation index; ΔTSI). In hypoxia, a similar minimal SpO₂ was reported in UNI and BIL but SpO₂ was lower in CYC (p = 0.047 and p = 0.021). ΔTSI during sprints and recoveries were similar in UNI and BIL but greater in CYC (p < 0.001) and in normoxia compared to hypoxia (main condition effect; p = 0.002). The power output was lower during KE exercises than during cycling, and no effect of hypoxia has been reported. The main results of this study indicate that unilateral and bilateral KE at high intensity induce comparable pulse and local muscular desaturation in hypoxia, and that these alterations are exacerbated during cycling.

This study addresses a critical limitation in existing computational tools for modeling post-exercise oxygen consumption kinetics (V̇O₂). Although exponential modeling provides practical insights into recovery dynamics, the inability to incorporate an individual's pre-exercise baseline oxygen consumption value (V̇O₂__baseline) can lead to inaccurate interpretations. A user-defined baseline allows for more precise modeling by aligning recovery kinetics with the true physiological endpoint, representing the individual's actual recovery target after a sufficient rest. To overcome this limitation, this study employs a customized Python algorithm that incorporates user-defined baseline V̇O₂ and uses both mono-exponential and bi-exponential models, aiming to improve upon existing analytical methods. Twenty-two male amateur soccer players participated in this study and performed a 30-s Wingate test. V̇O₂ was measured continuously before, during, and after exercise via a metabolic gas analyzer. Both mono-exponential and bi-exponential models were used to analyze post-exercise V̇O₂ kinetics. The analysis was performed using Origin software (as the reference tool), GedaeLab (a specialized web-based platform), and a custom-developed Python algorithm. The bi-exponential model demonstrated superior fit compared to the mono-exponential model with higher determination coefficient (R²) values. Specifically, R² values were 0.963 ± 0.013 and 0.805 ± 0.078 for the bi-exponential and mono-exponential models, respectively. The bi-exponential model also provided a more accurate approximation of real post-exercise oxygen consumption integrals at both 5 min and 15 min. Additionally, variations in V̇O_{2_baseline} values had different impacts on key parameters in both models, showing that higher V̇O_{2_baseline} values generally improved the model fit in the mono-exponential model but had minimal impact on the bi-exponential model.

The field of vitamin D research in sport has stagnated, with a notable lack of new evidence challenging existing paradigms. Despite well-documented consequences of vitamin D deficiency in athletes, gaps remain in understanding the feasibility of best practices for measuring and managing vitamin D status in elite sports. This survey aimed to define whether practitioners test athletes’ vitamin D status, the methods used, decision-making regarding supplementation and sources of information on vitamin D. Seventy-four stakeholders from 26 sports and parasports participated, representing athletes of eight ethnicities across the United States, United Kingdom, Europe, Australia and Asia. Financial and logistical constraints were significant barriers to effective vitamin D testing and management. Testing practices varied widely, with venous blood sampling being the most common method. Many practitioners were unaware of the specific analytical methods used. Supplementation decisions were typically collaborative, involving the sport science support team, but approaches and criteria varied considerably among practitioners. Most sourced information were from academic literature and consultations. These results are the first to characterise the perceptions and practices of practitioners in elite sport and parasport regarding vitamin D testing and supplementation. Despite extensive literature on the vitamin D status of athletes and its impact on performance, our findings indicate stagnation in innovative practices for optimising vitamin D status. Technological improvements to reduce testing costs and collaborative approaches between practitioners and researchers could facilitate knowledge delivery and improve practices.

Hormonal-induced water retention during the menstrual cycle (MC) may affect the estimates of body composition (BC) parameters depending on the MC phase if tissue hydration or volume is part of the BC analysis equations. Given this, MC phase-dependent changes of BC parameters might be expected within females for bioelectrical impedance analysis (BIA) or air-displacement plethysmography (ADP), whereas skin-fold calipometry (CAL) might not be affected. This study aimed to evaluate BC analyses during a regular MC by means of BIA and ADP with CAL serving as a control method in females with or without hormonal contraception with males serving as a control group. In a case-control design with repeated measurements, BC was determined using BIA, ADP, and CAL in 54 participants (age 18–33; BMI 17.0–27.8) divided into females using hormonal contraceptives (HC) (n = 19), females using no-hormonal contraceptives (no-HC) (n = 17), and males (n = 18). BC was assessed on four cycle-related days (menstruation, late follicular, ovulation, and late luteal). There were only small intraindividual BC variations during the MC (CV% 0.5–5.2) and neither significant time effects within any group (p = 0.065–0.939) nor significant time*group interactions (p = 0.151–0.956) for all devices (BIA, ADP, CAL) in any BC parameter. The results indicate that hormonal-induced water retention, if any, during MC had no effect on BC estimates of ADP, BIA, and CAL or were too small to be identified neither in females with HC nor in females with no-HC.

This study described the recovery responses following match play and examined the effects of manipulating training load 48 h post-match in Italian Serie A youth soccer players. Forty-eight players were assessed using the countermovement jump (CMJ), isometric posterior-chain muscle test (IPC), muscle soreness and fatigue before (pre) and after (0.5 h post, 48 h post and 72 h post) a match. At 48 h post-match, players were randomly assigned to a complete training (CT; n = 26) or a reduced training (RT; n = 22) group. Recovery differences were analysed between time points and training groups, with training loads quantified on match day (MD) and match day plus two (MD + 2). Recovery measures were impaired immediately post-match (p < 0.05). IPC and muscle soreness demonstrated incomplete recovery 48 h post-match (p < 0.05), whereas CMJ and fatigue returned to baseline (p > 0.05). Training load on MD did not differ between groups (p > 0.05), whereas the CT group had higher load on MD + 2 compared to RT (p < 0.05). A significant time × group interaction was observed for CMJ height and IPC measures (p < 0.05), with reductions in physical performance observed in the CT group from 48 to 72 h post-match (p < 0.05). A youth soccer match acutely impaired physical performance and recovery status, with prolonged and incomplete recovery of hamstring force and elevated muscle soreness 48 h post-match. A high-volume and high-intensity session administered 48 h post-match negatively influenced physical performance compared to a moderate training session.

This study aimed to quantify the frequency of individual and team contact events during rugby union match play in top domestic and international men’s and women’s competitions. Analyst-coded player individual and team contact event types (tackles, carries, attacking rucks and defensive rucks, lineouts, scrums and mauls) from the 2022/2023 rugby union season were analysed from top domestic and international competitions across the world using generalised linear mixed models. For both women’s and men’s rugby, competitions generally had similar numbers of contact events per playing position. Where differences were observed, most ranged between 0.5 and six per contact event per full game equivalent (FGE). Similar trends were observed when comparing women’s to men’s rugby. However, within-game accumulation of these different contact events for certain positional groups may have a significant impact (e.g., a front five player called up from a Farah Palmer Cup team to play in WXV1 could be involved in as much as 6 more attacking rucks, 3 more tackles and 5 more mauls per game on average). Furthermore, the small differences between competitions per FGE may accrue across matches and thus result in far greater exposures across a season (e.g., a front five player in Premiership Rugby may make 48 more tackles over 20 matches than in Top 14 on average). Although a high proportion of contact events per FGE were similar between competitions and sexes per playing position, differences that were observed may have important implications for players transitioning between competitions and the long-term exposure of players to higher-risk contact events.

The purpose of this study was to examine how the work rate (WR) influences whole-body metabolic rate (MR) and more local measures of intensity (i.e., pole power, joint power, and triceps brachii (TB) and vastus lateralis (VL) tissue saturation index (TSI)) across skating style sub-techniques in cross-country skiing (XCS). Five-minute efforts were performed at a range of submaximal speeds at constant inclines of 2% for G4, 5% for G3, and 12% for G2. Pole forces and 3D motion capture were used to calculate pole, elbow, and shoulder power. TSI in the TB and VL muscles was measured using near-infrared spectroscopy. There was a significant interaction effect of WR and sub-technique on MR (p < 0.001), with a steeper slope in G4 followed by G3 and G2. Similar interaction effects were evident for shoulder power (p < 0.001), but neither for elbow power (p = 0.512) nor for arm or leg tissue saturation (p = 0.766). Relative pole and arm power contributions were independent of WR but differed between sub-techniques. Both VL and TB had greater TSI in G4 (p = 0.025) and G3 (p < 0.001), respectively, compared to G2, and the triceps brachii had a ∼15 ± 7% (p < 0.001) greater TSI than the vastus lateralis across sub-techniques. Differences in WR-induced responses on various metabolic and mechanical responses across sub-techniques demonstrate the necessity of a more nuanced view on exercise load and intensity, especially on the local joint and muscle level, in XCS.

Athlete development is considered a multi-factorial and dynamic overtime process. Thus, understanding what factors and behavioural activities contribute most to development is important. The present study examined longitudinal relationships between training time and maturity status with physical performance indices in youth volleyball players. Prospective mixed longitudinal tracking over 3 years. Participants were N = 78 selected male volleyball players, aged 11–15 years (M = 13.81, SD = 1.20 years) from N = 41 competitive Swiss clubs. Alongside coach-reported weekly training time, participants completed standardised anthropometric and physical performance tests (e.g., standing long jump [SLJ]; 9-3-6-3-9 agility sprint). Linear mixed models (LMM) examined longitudinal independent and interacting relationships between training time and maturity status (years from peak height velocity; PHV) with physical performance. For SLJ, both training time and maturity status explained curvilinear longitudinal performance development, but nonlinear maturation status interactions were most influential, moderating relationships. In agility sprint, similar trends were apparent, with training time influences diminishing when maturity status was added in LMM analyses. Across time points of maturational growth, increased training engagement was not associated with enhanced physical performance benefits, whereas maturational status progression better accounted for performance differences and development. For coaches and sports-science practitioners, findings question the rationale for heightened training engagement at circa-PHV directed towards physical performance development purposes, a recommendation aligned with the need for maturational-growth associated injury prevention. Instead, due to musculoskeletal and proprioceptive disturbance during maturational growth, training emphasis on technical/biomechanical skill acquisition remains important.