Biology of Sport最新文献

Sprint interval training (SIT) is a potent exercise strategy to enhance athletes' aerobic capacity in a time-efficient manner. The purpose of this study was to examine the effect of a low-volume court-based SIT program on aerobic capacity and sport-specific endurance performance for competitive tennis players. Sixteen competitive collegiate tennis players were randomly assigned to the SIT (court-based repeated-sprint training) and traditional endurance training (ET; 45-min continuous treadmill running) groups for a 6-week intervention (3 sessions/week). The maximal oxygen uptake ( $\dot{\text{V}}$ O_2max), minute ventilation at peak exercise (VEmax), ventilatory anaerobic threshold in percentage of $\dot{\text{V}}$ O_2max (VT/VO₂), and elimination rate of blood lactate (BLA_er) were assessed, whereas the Yo-Yo Intermittent Recovery Test Level 2 (YoYo-IR2) and the tennis-specific HIT&TURN test were conducted at baseline and after the intervention. Both SIT and ET showed significant improvements in $\dot{\text{V}}$ O_2max (p < 0.01) with moderate effect sizes (ES = 0.64 and 0.98, respectively), as well as in VE_max (p < 0.01) with small effect sizes (ES = 0.23 and 0.21, respectively), and VT/VO₂ (p < 0.01) with large effect sizes (ES = 2.37 and 3.85, respectively). The BLA_er improved significantly in SIT (ES = 1.03; p < 0.05) whereas no significant changes occurred in ET. The magnitude-based decision showed a clear and superior improvement in both YoYo-IR2 (ES = 0.69) and HIT&TURN (ES = 1.72) tests in SIT than ET. Compared with traditional ET, court-based SIT can be a time-efficient strategy to improve aerobic capacity and tennis-specific endurance without requiring specialized equipment for competitive tennis players.

Prospectively collected injury surveillance data are essential for designing and implementing injury prevention programmes. We investigated the incidence, characteristics and patterns of professional football injuries in Qatar, providing details on the most observed injuries' burden. We prospectively recorded individual time-loss injuries and training/match exposure from 17 professional football teams in Qatar during 8 seasons (2014/15 to 2021/22). Injury definitions and data collection procedures followed the 2006 consensus statement and results reported according to the 2020 IOC consensus statement on football injuries and methodology of epidemiological studies on injuries, respectively. In total, 1466 players with 4789 registered injuries were followed. The overall injury burden was 129 [95% CI: 128-130] days/1000 h. Over the 8 seasons there was a significant decreasing trend in the incidence of gradual onset injuries (p = 0.0012) and a non-significant decreasing trend for suddenonset match injuries (p = 0.063). The injury burden for match injuries was greater than the burden resulting from training injuries (460 [95% CI: 460-460] vs 56 [95% CI: 55-57] days/1000 h, p < 0.0001). There was no difference in time loss between index and recurrent injuries. Hamstring muscle strain represented the most frequent injury with a median of 11 (inter-quartile 5-20) days to return to play (RTP). ACL complete tear was the most impactful injury, in term of return to play, with a median of 200 (116-253) days to RTP. Re-injuries constituted 10.8% (4.7% of exacerbations). Mean illness incidence was 1.1 (SD = 0.4) illness/1000 hours, representing 5 illnesses per squad per season, with no variation over time. Qatari professional football is characterized by an overall injury pattern and risk similar to Asian and European norms. There was a significant decreasing trend in the incidence of gradual onset injuries and a non-significant decreasing trend for sudden-onset match injuries.

Oxidative stress is augmented under hypoxic environments, which may be attenuated with antioxidant supplementation. We investigated the effects of dietary nitrate (NO₃-) supplementation combined with high-intensity training performed under hypoxic conditions on antioxidant/pro-oxidant balance. Thirty trained participants were assigned to one of three groups - HNO: hypoxia (13% F_iO₂) + NO₃-; HPL: hypoxia + placebo; CON: normoxia (20.9% F_iO₂) + placebo - while performing 12 cycling high-intensity interval training (HIIT) sessions during a 4-week period (3 sessions/week). Before and after the intervention, venous blood samples were collected and a time to exhaustion test (T_lim) was performed (with vastus lateralis changes in local O₂ saturation: SmO₂ monitoring). Glutathione peroxidase (GPX) activity increased in CON (p = 0.017, ~20%) and superoxide dismutase (SOD), catalase and ferric-reducing antioxidant power (FRAP) did not change in any group. Malondialdehydes (MDA) increased in both HNO (p = 0.001, ~60%) and CON (p = 0.023, ~30%) but not in HPL. Advanced oxidation protein products (AOPP), uric acid, and myeloperoxidase activity were not modified by the protocol. Only the CON group recovered faster after the T_lim test (SmO_2recovery: p = 0.0003, ~58%). Hypoxic exposure during high-intensity training blunted the increase in GPX and MDA after the intervention period. However, the effects of NO₃- supplementation seem to very slightly mitigate the detrimental effect of performing high-intensity training under hypoxic conditions.

The purpose of this study was to examine the effects of linear sprint training (LST) compared to curvilinear sprint training (CST) using an equivalent session training volume, on linear (LS) and curvilinear (CS) sprint performance, horizontal force-velocity profile, and change of direction (COD) ability in young soccer players. In a randomized pre-post parallel-group trial design, nineteen U16 male soccer players were randomly assigned to LST (n = 9) and CST (n = 10) groups. Both groups performed 11 sprint training sessions over 6 weeks. Before and after the training period, LS (5 m, 10 m, 15 m, 20 m, and 30 m), CS (weak and good side), horizontal force-velocity profile, and COD speed (modified 505 test) were assessed. The LST showed small to moderate significant enhancements (p ≤ 0.05) in LS (except 5 m sprint), modified 505 test, theoretical maximal velocity (V₀), maximal power output (P_max), and maximal ratio of force (RF_peak) from pre-test to post-test. CST resulted in small to moderate significant improvements (p ≤ 0.05) in 10 m, 20 m, and 30 m LS performance, weak and good sides of the CS, COD speed, and P_max from pre-test to post-test. In addition, significant between-group comparisons were observed between LST and CST for CS performance in both sides (p < 0.01). In conclusion, LST and CST seem to produce trajectory-specific adaptations in young soccer players. Therefore, strength and conditioning coaches should integrate both LST and CST training methods to effectively prepare soccer players and enhance their sprinting performance.

This study aimed to describe and compare specific matchdays sessions and playing positions external load during congested fixtures in elite football when combining the objectives from two different training days in one session. Data was collected from 27 players from the 1^st Brazilian division (28.7 ± 18.61 years) that participated in the following training days during congested fixtures (n = 16 weeks): a) Match day+1 (MD+1^MD-2, session 1 day after the game with tasks from MD+1 and MD-2 sessions, n = 9); b) Matchday-2 (MD-2^MD+2, session 2 days prior to subsequent match with tasks from MD-2 and MD+2 sessions, n = 11); c) Matchday-1 (MD-1^MD+2, session 1 day prior to subsequent match with tasks from MD-1 and MD+2 sessions, n = 12); and d) Matchday-1 (MD-1^MD+3, session 1 day prior to subsequent match with tasks from MD-1 and MD+3 sessions, n = 11). External load was collected with global positioning systems, while internal load with the rating of perceived exertion (RPE). The MD+1^MD-2 showed higher total distance covered (F = 116.92, p < 0.001) and player load (F = 56.67, p < 0.001) values than the other three training days, while both the MD+1^MD-2 and MD-2^MD+2 revealed higher distance covered at high-speed running (F = 22.43, p < 0.001) and high metabolic load distance covered (F = 75.98, p < 0.001) than both MD-1 sessions. Fullbacks covered higher high-speed running distance (F = 3.6, p = 0.033) than center backs, while midfielders reported higher RPE (F = 5.29, p = 0.003) values than defensive midfielders and fullbacks. Coaches may use the MD+1^MD-2 to emphasize total distance covered, while both MD+1^MD-2 and MD-2^MD+2 to promote HSR and HML distance compared to MD-1 sessions. In addition, combining training sessions allows to normalize external load across playing positions with the exception of fullbacks that are exposed to higher stimulus.

The objective of this study was to characterize surveyed coaches and elucidate the practices of physical fitness assessment and monitoring for both male and female athletes across three countries. A total of 165 coaches participated by completing a comprehensive 32-question survey. Pre-season assessments are a priority for coaches, with a significant range from 60.5% to 87.7% in Romania, while Portuguese and Spanish coaches tend to prefer testing during the competition (26.3% and 16.9%, respectively). Portuguese and Spanish coaches predominantly favor aerobic tests (50% and 46.8% respectively), whereas Romanian coaches exhibit a preference for sprint (56.9%) and skill tests (52.3%). Notably, change of direction tests are less commonly employed, ranging from 10.5% to 21% across the countries. In terms of exercise intensity determination, Portuguese coaches predominantly employ maximal heart rate (31.6%), while Spanish coaches often rely on the 220-age formula or perceived exertion (27.4%). For strength assessment, Portuguese coaches lean towards direct (34.2%) or estimated (31.6%) maximal repetition methods. When it comes to maximal speed sprint, Portuguese and Romanian coaches show preference (50% and 43.1% respectively), while Spanish coaches exhibit a relative lack of emphasis on individualized speed measures (37.1%). Perceptual scales are the preferred method for recovery monitoring, with adoption rates of 57.9% in Portugal, 53.2% in Spain, and 44.6% in Romania. In summary, this study underscores the distinct assessment and monitoring practices employed by coaches in Portugal, Spain, and Romania. These findings are in alignment with established literature standards, highlighting the diversity of approaches used in different countries.

Understanding the influence of contextual factors on physical demands is essential to maximize performance in handball. The purpose of this study was to explore and compare the influence of contextual factors (halves of the match, level of the opponent, match outcome and player role) on external load during official matches in women's handball. Twenty-two semi-professional female players from the Spanish 2^nd Division were monitored across 13 official home matches. Total distance covered (TDC), high-speed running distance (HSR), high-intensity breaking distance (HIBD), accelerations (ACC), decelerations (DEC) and PlayerLoad (PL) were collected in absolute and relative values (normalized by playing time) using a local positioning system (WIMU PRO, Realtrack Systems S.L., Almería, Spain). HSR, HSR/min and HIBD/min decreased during the second half (p < 0.05; small effects). Regarding the level of the opponent, high-level and middle-level teams elicited higher TDC/min, HIBD/min and PL/min than low-level teams (p < 0.05; small-moderate effects). Additionally, starter players exhibited higher absolute values of external load (TDC, HSR, HIBD, ACC, DEC and PL) compared to non-starters (p < 0.05; moderate-large effects). Match outcome did not affect the physical demands (p > 0.05). The study indicated that halves of the match, level of the opponent, and player role influenced external load experienced by players during official matches; specifically, starter players showed higher absolute values of external load compared to non-starters. This information should be considered in managing load and developing strategies to minimize fatigue and enhance performance during matches.

This study analyzed the physiological and physical demands of recreational team handball (RTH) and the training sessions' (matches) intensity variability in 50-77-year-old postmenopausal women (n = 20) without prior experience with the sport. Heart rate (HR), blood lactate, rating of perceived exertion (RPE), distance covered, time spent in different locomotor categories, accelerations, decelerations, Player Load (PL), game actions and fun levels were evaluated in 245 matches, played indoor (n = 130) or outdoor (n = 115), as small-sided games (3 × 15-min periods). Mean and peak HRs were 79 and 88% of maximal HR (%HR_max), showing reliable values across the training sessions, with time spent in the HR zones showing excellent relative reliability, though poor absolute reliability. Time spent > 80 and > 90%HR_max was 48% and 14% of total match time, respectively. Mean and peak blood lactate values were 2.6 ± 0.8 and 2.9 ± 0.9 mmol · l^-1, respectively. RPE was 5.5 ± 1.5, showing good relative though poor absolute reliability, and fun levels were 8.4 ± 1.1 (0-10 scale). Total distance covered was 1878 ± 333 m and the participants spent 54%, 3% and < 1% of total match time walking, fast running and sprinting, respectively. Total PL was 224 ± 41 (AU), with 67% of total match time being spent in low-intensity zones. Participants performed a total of 38 specific high-demanding actions per match, mainly throws (10.6 ± 5.8) and stops (11.0 ± 3.6). RTH training, played as small-sided games, is a high-intensity exercise training mode with high aerobic and anaerobic demands, low RPE and high fun levels for 50-77-year-old women without prior experience with the sport. Average cardiovascular demands were consistent across the training sessions.

The World Health Organization's declaration of mpox (formerly known as monkeypox) as a public health emergency of international concern (PHEIC) in July 2022, followed by its resurgence in 2024, has sparked concerns about its potential impact on sports, especially contact sports such as football. Although mpox is not a pandemic (as of late September 2024), the coronavirus disease 2019 (COVID-19) experience offers valuable lessons for proactive planning in sports. Our conceptual framework has been designed to draw insightful lessons from the COVID-19 pandemic to assist sports organizations in planning for and preventing similar situations. We aimed to draw lessons from COVID-19 to help sports organizations enhance practical preparedness through effective planning and mitigation strategies. Accordingly, we sought to assess the potential impact of mpox on sports, with a focus on football (soccer), and to develop strategies for prevention, management, and preparedness based on epidemiological insights and lessons from COVID-19 pandemic experience. Here we review mpox's pathophysiology and possibility of transmission in sports settings and discuss tailored strategies, including risk assessments, testing protocols, hygiene measures, and return-to-play policies. This review highlights key differences between mpox and COVID-19 in transmission, incubation, and management, emphasizing the need for customized prevention and control measures in sports. We propose innovative risk assessment methods using global positioning system tracking and machine learning for contact analysis, alongside tailored testing and hygiene protocols. We emphasize the importance of proactive planning, noting improved preparedness in the sports community compared to the early days of COVID-19. In conclusion, our proposed framework provides sports organizations with practical tools to manage potential risks associated with mpox, ensuring the continuity of activities while prioritizing public health.

New training approaches have emerged advocating for the implementation of compensatory physical training. This approach aims to provide additional training that balances the load typically experienced by non-starters during a match. This may help maintain their readiness and ensures that their physical fitness is not compromised by the reduced exposure to match loads. Thus, this narrative review aims to describe the differences in external loads between starting and non-starting players and describe the studies conducted in compensatory training. Studies examining external load metrics such as total distances covered, high-speed running, and sprinting suggest that, adjusted for playing time, values are often higher in non-starting players. Although not standardized, there is an obvious decrease in exposure for these critical variables in non-starters. Additionally, internal load parameters such as perceived exertion and heart rate tend to be higher in starting players. Regarding the physical fitness impacts, evidence suggests differences observed between starters and non-starters in some aspects of physical performance, although the extent and significance of these differences can vary. The studies on compensatory training are limited, and the typical approach usually centres on running-based exercises and small-sided games, offering differing approaches to address the physical needs. The gap in research underscores the necessity for improved study designs that can shed light on the real impact of compensatory training. Presently, the practice of compensatory training has been adopted, yet a definitive understanding of its genuine influence, particularly in terms of enhancing physical fitness and mitigating injury risks, remains elusive.