International journal of sports medicine最新文献

This study aimed to investigate the recovery of neuromuscular performance using mechanical parameters collected during jump (vertical and horizontal) and strength-power exercises in youth soccer players after official soccer matches. Twenty-one outfield highly trained youth male soccer athletes (age: 18.23±0.73 years; weight: 72.12±6.99 kg; height: 1.78±0.08 m) from two teams competing in the 1^st division of U-19 Portuguese National Championship participated in this study. Players completed a battery of physical tests at -2 h, + 30 min, +24 h, and +48 h in relation to the match. Countermovement jump height, horizontal jump distance, and bar velocity during the half squat, bench press, and hip thrust exercises, at fixed loads, were recorded. Countermovement jump was impaired until 24 h post-match (-: 1.7% from pre- to 24 h post-match, p=0.050; ES=-: 0.82). Half-squat bar velocity was reduced immediately following the match (-: 6.8% from pre-match, p=0.004; ES=-: 0.64) but recovered at +24 h (+2.9%, p=1.00; ES=0.02). Hip-thrust bar velocity was reduced for up to 48 h post-match (-: 7.4% from pre- to 48 h post-match, p<0.001; ES=-: 0.80). No impairments were found in the horizontal jump and bench press at any moment. Our findings show prolonged decrements in strength of the posterior chain following a soccer match, measured in the hip thrust exercise, while the other exercises displayed faster recovery dynamics.

Returning to sport after anterior cruciate ligament reconstruction (ACLR) can be a challenging and complex process for the athlete, with the rate of return to the pre-injury level of sport observed to be less than athlete expectations. Of the athletes that do return to sport (RTS), knee re-injury rates remain high, and multiple studies have observed impaired athletic performance upon RTS after ACLR as well as reduced playing time, productivity, and career lengths. To mitigate re-injury and improve RTS outcomes, multiple RTS after ACLR consensus statements/clinical practice guidelines have recommended objective RTS testing criteria to be met prior to medical clearance for unrestricted sports participation. While the achievement of RTS testing criteria can improve RTS rates after ACLR, current criteria do not appear valid for predicting safe RTS. Therefore, there is a need to review the various factors related to the successful return to the pre-injury level of sport after ACLR, clarify the utility of objective performance testing and RTS criteria, further discuss safe RTS decision-making as well as present strategies to reduce the risk of ACL injury/re-injury upon RTS. This article provides a practical review of the current RTS after ACLR literature, as well as makes medical recommendations for rehabilitation and RTS decision-making after ACLR.

The incidence of perturbed gastrointestinal integrity, as well as resulting systemic immune responses and gastrointestinal symptoms, otherwise known as exercised-induced gastrointestinal syndrome (EIGS), is common among individuals who partake in prolonged exercise. EIGS may cause the translocation of pathogenic material, including whole bacteria and bacterial endotoxins, from the lumen into circulation, which may progress into clinical consequences such as sepsis, and potentially subsequent fatality. However, further investigation is warranted to assess the possibility of food allergen and/or digestive enzyme luminal to circulatory translocation in response to exercise, and the clinical consequences. Findings from this narrative literature review demonstrate evidence that whole bacteria and bacterial endotoxins translocation from the gastrointestinal lumen to systemic circulation occurs in response to exercise stress, with a greater propensity of translocation occurring with accompanying heat exposure. It has also been demonstrated that food allergens can translocate from the lumen to systemic circulation in response to exercise stress and initiate anaphylaxis. To date, no research investigating the effect of exercise on the translocation of digestive enzymes from the lumen into systemic circulation exists. It is evident that EIGS and consequential pathogenic translocation presents life-threatening clinical implications, warranting the development and implementation of effective management strategies in at-risk populations.

We analyzed the effects of load magnitude and bar velocity variables on sensitivity to fatigue. Seventeen resistance-trained men (age=25.7±4.9 years; height=177.0±7.2 cm; body mass=77.7±12.3 kg; back-squat 1RM=145.0±33.9 kg; 1RM/body mass=1.86) participated in the study. Pre- and post-exercise changes in the mean propulsive velocity (MPV) and peak velocity (PV) in the back-squat at different intensities were compared with variations in the countermovement jump (CMJ). CMJ height decreased significantly from pre- to post-exercise (∆%=-7.5 to -10.4; p<0.01; ES=0.37 to 0.60). Bar velocity (MPV and PV) decreased across all loads (∆%=-4.0 to -12.5; p<0.01; ES=0.32 to 0.66). The decrease in performance was similar between the CMJ, MPV (40% and 80% 1RM; p=1.00), and PV (80% 1RM; p=1.00). The magnitude of reduction in CMJ performance was greater than MPV (60% 1RM; p=0.05) and PV (40% and 60% 1RM; p<0.01) at the post-exercise moment. Low systematic bias and acceptable levels of agreement were only found between CMJ and MPV at 40% and 80% 1RM (bias=0.35 to 1.59; ICC=0.51 to 0.71; CV=5.1% to 8.5%). These findings suggest that the back-squat at 40% or 80% 1RM using MPV provides optimal sensitivity to monitor fatigue through changes in bar velocity.

This study aimed to assess the seasonal evolution of field-based and laboratory-based performance indicators in cyclists. Thirteen Junior male road cyclists (age 17.4±0.5 years) were followed up during a season, which was divided in three phases: early season (involving mainly training sessions), mid-season (including the first competitions), and late season (including the major competitions of the season). During each phase, field-based power output data were registered for the assessment of maximum mean power values, and laboratory-based endurance (ramp test and simulated 8-minute time trial), muscle strength/power (squat, lunge, hip thrust) and body composition indicators (dual-energy X-ray absorptiometry) were also assessed. A progressive (p<0.01) increase in maximum mean power values (e.g., 3.8±0.3 and 4.5±0.4 watts/kg in early and late season, respectively, for 60-minute efforts) and on 8-minute time trial performance (i.e., 5.3±0.3 and 5.6±0.4 watts/kg, respectively) was observed through the season. Yet, more "traditional" endurance indicators (i.e., ventilatory threshold, respiratory compensation point, or maximum oxygen uptake) seemed to show a ceiling effect beyond the mid-season. In addition, neither peak power output, body composition, nor muscle strength indicators followed a similar pattern to the aforementioned field-based indicators. In summary, in Junior cyclists field-based indicators seem more sensitive to monitor endurance cyclists' changes in actual fitness and performance capacity than more "traditional" laboratory-based markers in Junior cyclists.

Groin problems are common in multidirectional sports. The aim of the present study is to assess seasonal, current, and trends for groin problems in rink hockey players, irrespective of their playing position, age, or gender. Rink hockey players from three countries [n=446 (162 female, 284 male)] were invited to participate in an online questionnaire. This form evaluated the prevalence of groin problems (time-loss and non-time-loss) for the 2022-2023 season, as well as monthly prevalence of groin problems (time-loss and non-time-loss). All groin problems were compared between playing position, gender, and age to assess between-group differences. Senior males reported the highest time-loss (25%) and non-time-loss (51%) for seasonal prevalence; while U-17 males reported the lowest in both categories of groin problems (time-loss 9%, non-time-loss 27%). No significant differences between playing position or gender were found for any of the groin problems analyzed. In-season prevalence (9-15.7%) of groin problems was significantly higher than pre-season (7.4%) prevalence (p<0.01). Seasonal prevalence of groin problems is common in rink hockey, regardless of gender, playing position, or age. Preventive efforts should be directed towards all players, regardless of their individual characteristics.

This study develops a comprehensive genotype-phenotype model for predicting the effects of resistance training on leg press performance. A cohort of physically inactive adults (N=193) underwent 12 weeks of resistance training, and measurements of maximum isokinetic leg press peak force, muscle mass, and thickness were taken before and after the intervention. Whole-genome genotyping was performed, and genome-wide association analysis identified 85 novel SNPs significantly associated with changes in leg press strength after training. A prediction model was constructed using stepwise linear regression, incorporating seven lead SNPs that explained 40.4% of the training effect variance. The polygenic score showed a significant positive correlation with changes in leg press strength. By integrating genomic markers and phenotypic indicators, the comprehensive prediction model explained 75.4% of the variance in the training effect. Additionally, five SNPs were found to potentially impact muscle contraction, metabolism, growth, and development through their association with REACTOME pathways. Individual responses to resistance training varied, with changes in leg press strength ranging from -55.83% to 151.20%. The study highlights the importance of genetic factors in predicting training outcomes and provides insights into the potential biological functions underlying resistance training effects. The comprehensive model offers valuable guidance for personalized fitness programs based on individual genetic profiles and phenotypic characteristics.

The aim of this study was to characterize the right ventricular (RV) contraction pattern and its associations with exercise capacity in a large cohort of adolescent athletes using resting three-dimensional echocardiography (3DE). We enrolled 215 adolescent athletes (16±1 years, 169 males, 12±6 hours of training/week) and compared them to 38 age and sex-matched healthy, sedentary adolescents. We measured the 3DE-derived biventricular ejection fractions (EF). We also determined the relative contributions of longitudinal EF (LEF/RVEF) and radial EF (REF/RVEF) to the RVEF. Same-day cardiopulmonary exercise testing was performed to calculate VO₂/kg. Both LV and RVEFs were significantly lower (athletes vs. controls; LVEF: 57±4 vs 61±3, RVEF: 55±5 vs 60±5%, p<0.001). Interestingly, while the relative contribution of radial shortening to the global RV EF was also reduced (REF/RVEF: 0.40±0.10 vs 0.49±0.06, p<0.001), the contribution of the longitudinal contraction was significantly higher in athletes (LEF/RVEF: 0.45±0.08 vs 0.40±0.07, p<0.01). The supernormal longitudinal shortening correlated weakly with a higher VO₂/kg (r=0.138, P=0.044). Similarly to the adult athlete's heart, the cardiac adaptation of adolescent athletes comprises higher biventricular volumes and lower resting functional measures with supernormal RV longitudinal shortening. Characteristic exercise-induced structural and functional cardiac changes are already present in adolescence.

This review aimed to verify the effects of vitamin E supplementation on oxidative stress, inflammatory response, muscle damage, soreness, and strength in healthy adults after exercise. We searched the MEDLINE, EMBASE, SPORTDiscus, Cochrane CENTRAL, and Web of Science from inception to August 2023, with no language restrictions. We included randomized placebo-controlled trials evaluating the supplementation of vitamin E on the abovementioned outcomes after a bout of physical exercise in healthy participants (no restriction for publication year or language). Meta-analyses were conducted to compare vitamin E and placebo supplementations to obtain a 95% confidence interval (95%IC). Twenty studies were included (n=298 participants). The effect of supplementation was assessed between 0 h and 96 h after the exercise. Compared to placebo, vitamin E had no effects on lipid (95%IC= -0.09 to 0.42), protein (-2.44 to 3.11), SOD (-1.05 to 0.23), interleukin-6 (-0.18 to 1.16), creatine kinase (-0.33 to 0.27), muscle soreness (-1.92 to 0.69), and muscle strength (-1.07 to 0.34). Heterogeneity for the analyses on carbonyls, interleukin-6 (1 h and 3 h), and muscle soreness ranged between 70 to 94%. Supplementing with vitamin E should not be recommended to support the recovery process in healthy individuals after exercise, given the lack of efficacy in the analyzed variables following an exercise session.

This study aimed to identify the relationship between exercise-induced hypertension and carotid artery intima-media thickness in long-distance runners. Sixty healthy male runners aged 40 to 60 years were assigned to the following three groups based on resting blood pressure and maximal systolic blood pressure during a maximal exercise test: normal blood pressure response, exercise-induced hypertension, and complex hypertension. An exaggerated systolic blood pressure response was defined as a maximal systolic blood pressure+≥+210 mmHg during the maximal exercise test, while carotid intima-media thickness was measured using B-mode ultrasonography. The carotid intima-media thickness mean values were the highest in the complex hypertension group (0.72±0.11 mm), followed by exercise-induced hypertension (0.62±0.12 mm) and normal blood pressure groups (0.55±0.13 mm), with a significant difference between the groups (p+<+0.002). In linear regression analysis, the mean intima-media thickness was independently associated with age (p=0.015) and maximal systolic blood pressure (p=0.046) but not with resting systolic blood pressure. These results suggest that exercise-induced hypertension is associated with carotid intima-media thickness, a surrogate marker of cardiovascular disease, in long-distance runners. Therefore, evaluating the blood pressure response during exercise is important for the early detection of potential cardiovascular disease risks in long-distance runners.