International journal of sports medicine最新文献

The study aimed to investigate the incidence of musculoskeletal injuries among table tennis players and identify their associated risk factors. We conducted a literature search in online databases using relevant search terms related to "table tennis" and "injury". To compare the rate of injuries according to player-related variables, we extracted information on sex, level of games, circumstances of injury, and duration of sport absence after injury. Furthermore, we calculated the odds ratios based on the number of injuries according to variables. Eight articles included 873 professional table tennis players, revealing an overall musculoskeletal injury rate of 3.6% (31 musculoskeletal injuries). The incidence was 10.0 injuries per 1,000 playing hours (range, 0-27.0). The rate of musculoskeletal injuries for female and male players were 3.2% and 3.8%, respectively, and those for Summer Olympic Games, Asian Games, and domestic national games was 4.8%, 15.4%, and 0%, respectively. More than half (52%) of injuries occurred during training, and most injuries (64%) were of a nature that did not cause time loss. This review provides valuable information about the incidence of musculoskeletal injuries in table tennis competitions. However, owing to the limitations of this study in identifying injury-related risk factors, future studies analyzing comprehensive variables are required.

Ankle destabilizing devices were developed to improve the recruitment of the evertor muscles. Nevertheless, the activity of lower-leg muscles has never been compared to each other during functional tests performed with destabilization. The objectives were i) to compare the electromyographic activity between the lower-leg muscles during four functional tests performed with ankle destabilization, and ii) to determine sex-related differences in neuromuscular activation. Twenty-six healthy volunteers (13 males, 13 females) performed the modified Star Excursion Balance Test (mSEBT), unipedal balance and weight-bearing inversion and eversion tests with a destabilizing device, while recording electromyographic activity of the peroneus longus and brevis, tibialis anterior, gastrocnemius lateralis and gluteus medius. The activity of peroneal muscles was significantly greater than other muscles during all functional tests. Furthermore, the anterior direction of the mSEBT was the one implying the greatest activity of the peroneus longus muscle compared to the posteromedial (p=0.003) or posterolateral (p<0.001) directions. Finally, no significant sex-related differences in neuromuscular activity were reported. This study highlights the effectiveness of the destabilizing device to involve specifically the peroneal muscles when performing various functional tests. This device should be used by clinicians to be more specific to the stabilizers of the ankle joint during functional exercises.

The combination of high volume of moderate-intensity continuous training with a low volume of high-intensity interval training improved body composition and physical capacities in individuals with obesity. However, polarized training (POL) has never been used in adult men with obesity. Thus, the purpose of this study was to investigate changes in body composition and physical capacities induced by a 24-week POL or threshold (THR) program in obese male adults. Twenty male patients (mean age 39.8±6.3 yrs; mean body mass index [BMI] 31.6±2.7 kg∙m^-2) participated in this study (n: 10 POL, n: 10 THR). After 24-week, body mass (BM) and fat mass (FM) decreased by -3.20±3.10 kg (P<0.05) and -3.80±2.80 kg (P<0.05), respectively, similarly in both groups. Maximal oxygen uptake (  ̇VO₂max) and   ̇VO₂ at respiratory compensation point (RCP) increased in the POL group (+8.5±12.2 and+9.0±17.0%, P<0.05) and in the THR group (+4.24±8.64 and+4.0±6.70%, P<0.05), as well   ̇VO₂ at gas exchange threshold (GET) increased similarly in both groups (+12.8±12.0%, P<0.05). POL and THR were equally effective in improving body composition and physical capacities in obese subjects. Future studies are needed to determine whether adherence to the training program can be improved by adding a running competition compared with a group without competition at the end of the training program.

This meta-data exploration aimed to determine the impact of exertional-heat stress (EHS) on gastrointestinal status of masters age and young adult endurance athletes. Sixteen MASTERS (mean: 44y) and twenty-one YOUNG (26y) recreational endurance athletes completed 2 h of running at 60% ˙V O_2max in 35˚C ambient conditions. Blood samples were collected pre-, immediately and 1 h post-EHS, and analyzed for markers of exercise-induced gastrointestinal syndrome (EIGS). Thermo-physiological measures and gastrointestinal symptoms (GIS) were recorded every 10-20 min during EHS. Peak Δ pre- to post-EHS did not substantially differ (p>0.05) between MASTERS and YOUNG for intestinal epithelial injury [I-FABP: 1652pg/ml vs. 1524pg/ml, respectively], bacterial endotoxic translocation [sCD14: -0.09µg/mL vs. 0.84µg/mL, respectively], lipopolysaccharide-binding protein [LBP: 0.26µg/mL vs. 1.76µg/mL, respectively], and systemic inflammatory response profile (SIR-Profile: 92.0arb.unit vs. 154arb.unit, respectively). A significantly higher peak Δ pre- to post-EHS in endogenous endotoxin anti-body IgM (p=0.042), and pro-inflammatory cytokine IL-1β (p=0.038), was observed in YOUNG compared to MASTERS. No difference was observed between incidence (81% and 80%, respectively) and severity (summative accumulation: 21 and 30, respectively) of reported GIS during EHS between MASTERS and YOUNG. Pathophysiology of EIGS in response to EHS does not substantially differ with age progression, since masters and younger adult endurance athletes responded comparably.

This study aimed to test the reproducibility of the 3-min all-out effort applied using shuttle running and compare its values to aerobic parameters. On the first day, 14 futsal players underwent an exhaustive test to determine the maximal incremental speed (MIS) and anaerobic threshold (AnT). On the second day, the participants performed the 3-min all-out effort (n=14), which was repeated after 48 h (third day) to test its reproducibility (n=11). Peak oxygen consumption (V̇ O_2PEAK) and peak blood lactate concentrations ([La-]) were determined from 3-min all-out efforts performed through a 20-m shuttle run on the official court. The distance covered, mean speed, and critical speed (CS) during the 3-min all-out presented direct relationships with aerobic parameters determined through the incremental test (r>0.62). The distance covered above CS (D') presented a direct relationship with peak lactate concentrations induced by a 3-min all-out effort (r=0.81). Despite the acceptable levels of reproducibility observed for most of the 3-min all-out variables, the minimal detectable change for D' was high (72%). Our results demonstrated the potential use of mean speed to evaluate aerobic fitness. However, the applicability of the 3-min all-out shuttle run test to monitor training adaptations should be avoided, at least in nonexperienced athletes.

This study aimed to assess the self-reported frequency and severity of gastrointestinal symptoms (GIS) at rest and around rugby training and match play in male and female rugby union players. An online questionnaire was sent to registered rugby union players (sevens or fifteens). Thirteen GIS were assessed alongside perceptions of appetite around rugby and rest using Likert and visual analog scales. Questions investigating a range of medical and dietary factors were included. Three hundred and twenty-five players (male n=271, female n=54) participated in the study. More frequent GIS (at least one GIS experienced weekly/more often) was reported by players at rest (n=203; 62%) compared to around rugby (n=154; 47%). The overall severity of GIS was low (mild discomfort), but a portion of players (33%) did report symptoms of moderate severity around rugby. Female players reported more frequent and severe symptoms compared to male counterparts (p<0.001). Self-reported appetite was significantly lower after matches compared to training. There were no dietary or medical factors associated with GIS severity scores. This study describes GIS characteristics in male and female rugby union players. Half of the players assessed experienced some form of GIS that may affect nutrition, training, or performance, and should thus be a consideration for practitioners supporting this cohort.

Resistance training intensity is commonly quantified as the load lifted relative to an individual's maximal dynamic strength. This approach, known as percent-based training, necessitates evaluating the one-repetition maximum (1RM) for the core exercises incorporated in a resistance training program. However, a major limitation of rigid percent-based training lies in the demanding nature of directly testing the 1RM from technical, physical, and psychological perspectives. A potential solution that has gained popularity in the last two decades to facilitate the implementation of percent-based training involves the estimation of the 1RM by recording the lifting velocity against submaximal loads. This review examines the three main methods for prescribing relative loads (%1RM) based on lifting velocity monitoring: (i) velocity zones, (ii) generalized load-velocity relationships, and (iii) individualized load-velocity relationships. The article concludes by discussing a number of factors that should be considered for simplifying the testing procedures while maintaining the accuracy of individualized L-V relationships to predict the 1RM and establish the resultant individualized %1RM-velocity relationship: (i) exercise selection, (ii) type of velocity variable, (iii) regression model, (iv) number of loads, (v) location of experimental points on the load-velocity relationship, (vi) minimal velocity threshold, (vii) provision of velocity feedback, and (viii) velocity monitoring device.

This study aimed to determine the influence of the testing environment (track vs. treadmill), time trial order (long-short vs. short-long), and timing (within-session vs. between-sessions) on the critical power (CP) and work over CP (W´), using the power metric in runners. Fifteen highly trained athletes performed three test sessions composed of two time trials of 9- and 3-min, separated by a 30-min rest period. One session was performed on a track, and two sessions on a treadmill, alternating the order of the time trials. The CP and W´ values determined on the track were significantly greater and lower than on the treadmill, respectively (p<0.001; CP≥89 W; W´≥3.7 kJ). Their degree of agreement was low (SEE CP>5%; W´>10%) and therefore was not interchangeable. There were no performance differences in the timing of the time trials (p=0.320). Lastly, performing the 9-min trial first resulted in a greater power output compared to when executed last (p<0.001; 4.9 W), although this resulted in similar CP and W´ values (Bias<5 and 10%, respectively). In conclusion, it is feasible to test CP and W´ in a single testing session, irrespective of the time trial order, although not interchangeably between track and treadmill.

Acute exercise induces changes within the T-cell compartment, especially in cytotoxic CD8⁺memory subsets, depending on exercise intensity and duration. It is unclear whether exercise-induced changes in major T-cell subsets differ in response to acute high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT) and whether sex-specific effects exist. Twenty-four recreationally active runners (females: n=12, 27.8±4.1years, 54.4±4.6 ml*kg^-1*min^-1; males: n=12, 31.6±3.8years, 58.9±7.7 ml*kg^-1*min^-1) participated in this randomized controlled crossover study, and conducted an energy- and duration-matched HIIT and MICT session. Blood was sampled before (T₁), immediately (T₂) and 1 h after exercise (T₃). Flow cytometry was used to identify T-cell populations. HIIT decreased the proportion of CD8⁺T-cells more pronounced at T₃ compared to MICT (p=0.007), induced a significantly stronger increase in the CD8⁺effector memory (T_EM) cell proportion at T₂ (p=0.032), and decreased CD4⁺central memory proportion more pronounced at T₂ (p=0.029). A decrease below baseline CD8⁺T_EM proportion at T₃ was observed only after HIIT (p<0.001). No interaction effects between sexes were revealed. Taken together, HIIT represents a more potent stimulus to induce shifts mainly within the cytotoxic CD8⁺T-cell compartment, thereby giving implications to investigate the role of HIIT on the cell´s effector phenotype and function in more detail.