International journal of sports medicine最新文献

This study aimed to evaluate the applicability of the 10-minute submaximal treadmill test (T10 test), a self-paced test, in determining critical speed (CS) and predicting running performance. Specifically, we sought to identify the percentage of T10 velocity (vT10) that runners performed in official distance races, and to compare physiological and performance indicators between sexes. 60 recreational runners (n=34 males and n=26 females) underwent a maximum incremental test, the novel T10 test, and ran 1200-m and 2400-m on the track. Runners self-reported their best performance times. Generalized Linear Model was used to compare running performances between sexes. For both males and females, the %vT10 in 5 km, 10 km, and half-marathon races occurred at 107.5% and 106.5%, 99.9% and 100.8%, and 92.6% and 97.1%, respectively. There was no interaction effect (p=0.520) and no main effect of sex (p=0.443). There was a main effect of distance (p<0.001), indicating that %vT10 in the 5km race differed from that found in the 10 km race (p=0.012), as well as in the half-marathon (p<0.001). Our findings suggest that %vT10 values can be used to determine pace in recreational endurance runners for race distances regardless of sex.

This study aimed to determine the influence of sport type and training volume during adolescence on low bone mineral density (BMD) in long-distance runners. In total, 125 competitive long-distance runners (64 males; 21.3±4.2 years, 61 females; 21.4±3.1 years) participated in this retrospective cohort study. We collected training history data during adolescence using a questionnaire and measured BMD of the lumbar spine and whole body using dual-energy X-ray absorptiometry (DXA). Male runners with low BMD ran for more hours (p=0.02) and had a smaller proportion of multidirectional loading activity (p=0.03) in elementary school than those with normal BMD. Although female runners with low BMD performed multidirectional activity for more hours in middle school than those with normal BMD (p=0.01), running volume was similar between groups. There was an increasing trend in the total number of hours of physical activity in middle school in female runners with low BMD (p=0.05). These results suggest that avoiding specialization in long-distance running, increasing the proportion of multidirectional sports, and preventing overload during the bone growth phase may reduce the risk of low BMD among runners.

Lateral ankle sprains have a high recurrence rate, often developing into chronic ankle instability (CAI). CAI affects movement strategy during side-cutting maneuvers, with inconsistent results in many studies. This study aimed to clarify the characteristics of movement strategies during side-cutting maneuvers in female soccer players with and without CAI. Thirteen female soccer players with CAI and twelve healthy controls performed 10 successful trials of side-cutting maneuvers in three directions (anterolateral, lateral, and posterolateral) under unanticipated conditions. Compared to the control group, the CAI group displayed an increased stance time in the lateral and posterolateral side-cutting maneuvers (lateral: p=0.021, effect size=0.97, posterolateral: p=0.014, effect size=1.00). In posterolateral side-cutting maneuvers, the CAI group displayed a decreased posterior ground reaction force at 19-30% and 42-54% of the entire stance phase compared with the control group (p=0.001, effect size=1.30-1.42). Female soccer players with CAI may display increased stance time to compensate for self-reported ankle instability and may also exhibit decreased braking and propulsive force when side-cutting to sharper angles. These observations suggest a hypothesis that could help in the assessment of cutting maneuvers under unanticipated conditions after ankle sprains.

This prospective cohort study investigated the predictive validity of the Functional Movement Screen (FMS) and Y Balance Test (YBT) for sports injuries in 458 collegiate athletes across various sports. Preseason screening using FMS and YBT was conducted, followed by injury data collection over the competitive season. Logistic regression analysis examined the relationship between screening scores and subsequent injury risk. Results indicated that lower composite FMS scores (≤14) were associated with increased injury risk (OR=2.32; 95% CI: 1.54-3.48; p<0.001), as were YBT anterior reach asymmetries > 4 cm (OR=2.16; 95% CI: 1.43-3.26; p<0.001). The combination of both risk factors demonstrated the strongest association (OR=3.57; 95% CI: 2.18-5.83; p<0.001) when compared to individuals with FMS scores >14 and YBT asymmetry < 4 cm.The combination of low FMS scores and YBT asymmetries demonstrated the strongest predictive value. These findings underscore the value of the FMS and YBT as screening tools to identify collegiate athletes who may be at elevated risk for sports injuries, potentially guiding the implementation of targeted injury prevention strategies.

High-intensity interval training (HIIT) has been suggested as an effective treatment approach of childhood obesity. The objective of the present study was to examine intensity, enjoyment, and perceived exertion of a 4x4-minute play-based HIIT program for children and adolescents with obesity. 83 participants (42.2% girls, 12.3±1.5 years, 57.8% boys, 12.0±1.6 years) completed a 12-week intervention comprising three weekly sessions. After nine sessions (weeks 2, 6, and 11), participants rated perceived exertion (RPE) with a Borg scale and enjoyment of activities using the Physical Activity Enjoyment Scale (PACES). Heart rate (HR) was recorded to assess time spent in high- and moderate-intensity. Participants spent more time in high-intensity during strength-based (P=0.004) and running-based (P=0.007) activities compared to ball games, and more time was spent in moderate-intensity during ball games compared to strength-based (P=0.033) and running-based (P=0.028) activities. Overall, boys spent more time in moderate-intensity than girls (P=0.007). Participants rated RPE lower for ball games than for strength-based (P<0.001) and running-based (P<0.001) activities. Boys rated running-based activities more enjoyable than girls (P=0.021). Exercise intensity and RPE vary by activity in HIIT for children and adolescents with obesity. Ball games led to less high-intensity time and were seen as less exhausting. No differences in RPE or enjoyment were found over time.

The aim of the present study was to examine: 1) the coexistence of excessive body weight and low cardiorespiratory fitness (CRF), at a level to be considered unhealthy, and 2) the stability (tracking) of this profile. 1754 European boys, aged 8- to 14-years old, were tested for CRF and based on international cut points were classified as having healthy (H) or unhealthy (UN) CRF. Based on BMI they were classified as having normal weight (N), or overweight or obesity (OO). Chi-square was performed with four groups (i.e. N/H, N/UN, OO/H and OO/UN) and the odds ratios were calculated (cross-sectional analysis). A sub-group of 353 boys were followed for an average of 3.79±0.83 years (range: 2.97- 6.06; longitudinal analysis). The odds that a boy was with OO/UN profile compared to the normal body weight category ranged from 2.67 (13-years old) to 6.74 (9-years old). 56.6% of the participants remained in the same category, whereas 28.0% of them had ≥1 change in category to worst in the second assessment (Cohen Kappa= 0.557, p<0.001; substantial agreement). The odds ratios of having boys with unhealthy profile of combined excessive body weight and low CRF ranged from medium to large. The stability of unhealthy profile was substantial.

Large cohort studies have reported that former professional football players have an increased risk of mortality from neurodegenerative disease. Due to emerging concerns regarding the safety of heading the technique is now banned for players under 12. The aim of this systematic review was to evaluate the association between heading exposure and cognitive function in professional football players. A search strategy was devised and entered into seven electronic databases: MEDLINE, Embase, Web of Science, PsycINFO, CENTRAL, SportDiscus and PEDro. The search identified 563 records. After screening records and applying the eligibility criteria, nine cross-sectional studies (n=925) were included in the review, investigating 452 current and 473 former players (859 males, 66 females). Six studies (n=595) reported evidence for an association between heading and impaired cognitive function, while three studies (n=330) reported no association. Diverse cognitive domains were investigated, which might underline the disparity in these results. The association between heading and cognitive function in professional football appears likely but remains inconclusive. Methodological heterogeneity and variability in the presentation of results limits the conclusions drawn. Prospective longitudinal studies using standardised methods, and including females, are required to provide evidence to support or refute an association.

Hydrogen, as an antioxidant, may have the potential to mitigate fatigue and improve selected oxidative stress markers induced by strenuous exercise. This study focused on a previously unexplored approach involving pre-exercise inhalation of hydrogen-rich gas (HRG). Twenty-four healthy adult men first completed pre-laboratories to determine maximum cycling power (W_max) and maximum cycling time (T_max). Then they were subjected to ride T_max at 80% W_max and 60-70 rpm on cycle ergometers after inhaled HRG or placebo gas (air) for 60-minute in a double-blind, counterbalanced, randomized, and crossover design. The cycling frequency in the fatigue modeling process and the rating of perceived exertion (RPE) at the beginning and end of the ride were recorded. Before gas inhalation and after fatigue modeling, visual analog scale (VAS) for fatigue and counter-movement jump (CMJ) were tested, and blood samples were obtained. The results showed that compared to a placebo, HRG inhalation induced significant improvement in VAS, RPE, the cycling frequency during the last 30 seconds in the fatigue modeling process, the ability to inhibit hydroxyl radicals, and serum lactate after exercise (p<0.028), but not in CMJ height and glutathione peroxidase activity. The cycling frequency during the last 30 seconds of all other segments in the fatigue modeling process was within the range of 60-70 rpm. In conclusion, HRG inhalation prior to acute exercise can alleviate exercise-induced fatigue, maintain functional performance, and improve hydroxyl radical and lactate levels.

Biceps femoris long head (BF_LH) aponeurosis size was compared between legs with and without prior hamstring strain injury (HSI) using two approaches: within-group (injured vs. uninjured legs of previous unilateral HSI athletes) and between-group (previously injured legs of HSI athletes vs. legs of No Prior HSI athletes). MRI scans were performed on currently healthy, competitive male athletes with Prior HSI history (n=23;≥1 verified BF_LH injury; including a sub-group with unilateral HSI history; most recent HSI 1.6±1.2 years ago) and pair-matched athletes with No Prior HSI history (n=23). Anonymized axial images were manually segmented to quantify BF_LH aponeurosis and muscle size. Prior unilateral HSI athletes' BF_LH aponeurosis maximum width, aponeurosis area, and aponeurosis:muscle area ratio were 14.0-19.6% smaller in previously injured vs. contralateral uninjured legs (paired t-test, 0.008≤P≤0.044). BF_LH aponeurosis maximum width and area were also 9.4-16.5% smaller in previously injured legs (n=28) from Prior HSI athletes vs. legs (n=46) of No Prior HSI athletes (unpaired t-test, 0.001≤P≤0.044). BF_LH aponeurosis size was smaller in legs with prior HSI vs. those without prior HSI. These findings suggest BF_LH aponeurosis size, especially maximum width, could be a potential cause or consequence of HSI, with prospective evidence needed to support or refute these possibilities.

This study investigates the biomechanical adaptations of the longitudinal arch (LA) in long-distance runners, focusing on changes in stiffness, angle, and moment during a 60-minute run. Twenty runners participated in this experiment, and were asked to run at a speed of 2.7 m·s^-1 for 60 minutes. The kinematic and kinetic data collected at five-minute intervals during running were calculated, including the stiffness of LA in the loading phase (k _load ) and the stiffness of LA in the unloading phase (k _unload ), the maximum LA moment (M _max ), the range of LA angle change (∆θ _range ), and the maximum LA angle change (∆θ _max ). Foot morphology was also scanned before and after running. Variations of kinematic and kinetic data were analyzed throughout the running activity, as well as variations of foot morphology pre- and post-run. Results showed that there was a significant decrease in k _load (p<0.001), coupled with increases in ∆θ _range (p=0.002) and ∆θ _max (p<0.001), during the first 15 minutes of running, which was followed by a period of mechanical stability. No differences were found in k _unload and M _max throughout the running process and the foot morphology remained unchanged after running. These results highlight a critical adaptation phase that may be pivotal for improving running economy and performance.