Journal of Sports Medicine and Physical Fitness最新文献

Background: Elite-level football requires an array of physical, technical, psychological, and tactical skills. The aim of this study was to measure the association between physical outputs (distance, decelerations, accelerations) and the match outcome (win, draw, lose) in professional football. This research also examined whether the same association is influenced if a team adopts a possession or transition-based playing style.

Methods: Thirty-six elite-outfield football players from an English Championship team participated in the study during the 2020/2021 and 2021/2022 seasons using physical and event data collected from an English Championship club over the 2020-2021 and 2021-2022 seasons, this study conducted a univariate analysis of variance (ANOVA) and Hedge g effect size (ES) to measure the research aims.

Results: The results showed no significant differences were found between match outcomes for each physical output metric calculated. There was a trivial ES shown for all conditions except decelerations, with win/lose having a moderate ES (g=0.53). When playing a possession-based playing style there was no significant difference or non-trivial ES found for any physical output and match outcomes. When playing a transition-based playing style there was a moderate ES found for win/draw (P=0.38, g=0.90) and win/loss (P=0.98, g=0.64).

Conclusions: This research provides important evidence for utilizing intense deceleration actions as a physical KPI during match play for teams adopting a transitional playing style. Subsequently, training interventions should be adopted to physically prepare players to complete and sustain intense deceleration actions during match play.

Background: Ironman-distance events are ultra-endurance competitions involving three sports, leading to various adverse medical incidents. While some athletes compete in the same event over multiple years, medical trends among repeat competitors have not been studied. This study aimed to determine the recurrence of common medical incidents in repeat competitors over time in a longstanding Ironman-distance championship event.

Methods: Data were collected using standardized sheets completed by nurses and physicians during athlete medical evaluations from 1989-2019. Competitors (N.=427) were included in the analysis if they received medical evaluation in at least three competitions within a fifteen-year period. Bivariate correlations were calculated to determine associations among medical incidents during competitors' first year of medical evaluation. Logistic regression analyses were performed to investigate the likelihood of medical incidents reoccurring in subsequent years following the initial occurrence.

Results: Significant associations were found between several adverse medical incidents during competitors' first medical evaluations and for those evaluated in 3+ years. Competitors diagnosed with hyponatremia (aOR=2.42, 95% CI: 1.07-5.46), nausea (aOR=1.83, 95% CI: 1.14-2.94), dizziness (aOR=1.71, 95% CI: 1.09-2.68), and muscle cramps (aOR=1.62, 95% CI: 1.05-2.50) during their first year were significantly more likely to return with the same issue in subsequent years. In contrast, those who experienced vomiting during their first year were less likely to return for the same problem (aOR=0.45, 95% CI: 0.27-0.77).

Conclusions: There are significant correlations and clear patterns of recurrence for specific medical incidents among elite ultra-endurance triathletes. Further analyses of other triathlon repeat populations and more specific examinations by age and sex are needed.

Skeletal muscle (SM) injuries are a very common occurrence among athletes during training and/or competitive periods, resulting in time loss and absence from sports. Of several existing interventions to improve SM recovery, the nutritional approach has emerged as integral part to improve the physiological response and maintain the body composition to promote a rapid and safe return to play. Growing evidence supports that the physiological response to SM injuries results in a number of changes, suggesting the relevance of a personalized nutritional approach, according to the degree of immobilization, SM mass loss, strength and function. Therefore, we aimed to review the current evidence of the nutritional approach applied to SM injuries recovery in athletes, highlighting energy intake, use the main nutrients and elements for the SM recovery, such as proteins, carbohydrates, vitamins and omega-3 fatty acids. Currently, evidence from injured athletes is scarce, and so specific guidelines cannot be established, calling from greater research into nutritional interventions in SM injury recovery in athletes.

Background: Treadmills have been used in laboratories to assess various measures related to walking and running. However, there has been some skepticism regarding their reliability as a representation of outdoor running. While marathon running has gained popularity as a form of physical activity, there have been few studies examining stride-to-stride variability after distance running, especially in relation to the duration and surface of running. This study compared stride time and lower limb joint angles during distance treadmill running and running over-ground. The hypothesis was that stride-to-stride variability would be influenced by running duration and surface, with greater variability observed during outdoor running.

Methods: Eleven runners participated in the study, running on a treadmill and over-ground for 31 minutes at their preferred speed. Inertial measurement units were used to measure stride time, total range of motion, and joint angles of the hip, knee, and ankle in different phases of the gait cycle in the sagittal plane movements. Mean and coefficient of variation of each parameter were compared between the initial and final 5 minutes of running on the treadmill and over-ground.

Results: There were no significant differences in stride time or its variability based on running duration or surface. However, mean and variability of certain lower limb joint angles were higher during outdoor running, supporting the hypothesis. Variability was higher in the initial duration of running as compared to final phase of running.

Conclusions: These findings suggest that treadmill may not fully reflect the dynamics of running over-ground. It is important to consider variability in gait analysis and research, as well as the potential impact on training and clinical practice.

Background: Despite the growing interest in trail running in several countries, few researchers have investigated why people practice trail running. Thus, this study aimed to identify the main motivational factors that determine adherence to trail running and their association with demographic characteristics and training habits among recreational runners.

Methods: This cross-sectional research employed a questionnaire as its measurement instrument to gather data on demographic characteristics, trail running practices, motivation among trail runners.

Results: The study examined 168 trail runners, with 66.7% being men. It verified significant differences in demographic characteristics and training habits only in the distance covered during races with sex (P=0.036). Additionally, the results showed that the primary motivations for trail runners to practice trail running were quality of life and leisure (86.3%), physical fitness (54.2%), and competition (34.5%). Motivation for quality of life and leisure was associated with marital status (P=0.033) and average distance travelled during training (P=0.011). Motivation for physical fitness was associated with the way trail running training is performed (P=0.012), while competitive motivation was associated with gender (P=0.001), race (P=0.028), and average distance travelled during training (P=0.015).

Conclusions: The findings indicate that the majority of runners practice trail running as a means of improving quality of life and leisure, followed by physical fitness and competition. Furthermore, significant associations were found between motivations and demographic characteristics as well as training habits.

Background: We examined the influence of muscle strength and aerobic fitness on wellbeing and muscle function recovery in female soccer players.

Methods: Sixteen players from the English Women's Super League (age: 26±4 yrs; height, 1.70±0.07 m; mass, 67.9±6.4 kg) completed an isometric mid-thigh pull test (IMTP) and maximal aerobic speed test (MAST). Using a median split, players were divided by strength into high (H-IMTP) and low (L-IMPT) groups and by fitness into high (H-MAST) and low (L-MAST) groups. Countermovement jump height (CMJ), Reactive Strength Index (RSI) and wellbeing were measured 2 days prematch, then 3 subsequent days post-match (M+1, M+2, M+3).

Results: In H-IMTP, CMJ, RSI and wellbeing were higher at M+1-M+3 (P<0.05). At M+3, CMJ in H-IMTP was 30.3±3.5 cm vs. 26.2±3.4 in L-IMTP. CMJ and wellbeing were unaffected by fitness, but RSI was lower at M+1-M+3 in the L-IMTP group (P<0.05).

Conclusions: In conclusion, isometrically stronger but not aerobically fitter female soccer players recover quicker after matches.

Background: Skyrunning is a running sport performed in a mountain environment, characterized by reaching an altitude of at least 2000 meters above sea level, where symptoms of acute mountain sickness can appear. This sport has recently gained significant popularity, with an increasing number of participants. The purpose of this study was to analyze female performances in the different subdisciplines of skyrunning.

Methods: The study considered official results of 173 races of the Italian Skyrunning Federation held in 2021 and 2022. Female and male biological sexes, as well as age and race time of 13,850 participants who crossed the finish line were analyzed.

Results: Female athletes represented 16% of finishers and showed a preference for competitions of medium distances (skyrace and skytrail). They were younger and more self-selected among the most talented in terms of performance compared to males (P<0.001). Males showed significantly faster race times than females in all the competitions (P<0.05). Race times of female winners were on average 123-144% higher than those of male counterparts. In both sexes, winners were predominantly young; female winners were more represented among the older age-groups in skyrace and vertical kilometer (P<0.05).

Conclusions: Regardless of biological differences affecting female sporting performances, gender inequalities are still widely present despite the progress made in every sport. Since gender equality in sports cannot be separated from gender equality in the sociocultural sphere, it is necessary to invest economically and take proactive measures to achieve real equity, both in the macro-social and sports contexts.

Background: Ultra-marathon trails involve a combination of specific physiological and mechanical constraints and raise new questions regarding the osteoarticular impact on the knees and the long-term risk of osteoarthritis. Magnetic resonance imaging (MRI) T2 relaxation time measurement has shown the ability to determine cartilage response to loading. Higher T2 measurements correspond with cartilage damage. The aim of this study was to quantify the changes in MRI T2 relaxation times of knee articular cartilage after an ultra-trail run and determine knee's consequences of regular practice.

Methods: Twenty participants in a 55-km race involving total elevation changes of 2600m had 1.5-T knee MRI prior to the race (V0), immediately after (V1) and one month after the race (V2) for T2 relaxation times measurement and morphological sequences (T1, T2 & T2 Fast-Spin Echo (FSE)).

Results: T2 measurements were significantly increased in V1 from V0 and remained so one month after the race (V2), despite a significant reduction from V1. Morphological sequences revealed that 65% of the participant had cartilage damage and 65% meniscal damage, 100% of which affected the posterior horn of the medial meniscus. Only one subject (5%) presented no anomaly whatsoever. Damage appeared to be stable between the assessments.

Conclusions: Ultra-trail running leads to modifications in the knee cartilage ultrastructure, which persists for at least one month after the event. Furthermore, regular ultra-trail runners present a high number of low-grade cartilage and meniscus lesions.

Background: This study investigates the effects of manipulating the number of ball touches (free play vs. two touches) on the physical and technical actions of elite male youth soccer players during 5v5 + 2 goalkeepers (GKs) small-sided games (SSGs).

Methods: Players played in two different SSGs: 1) free play, where the number of touches per possession was not restricted; and 2) two touches, where players were limited to a maximum of two touches per ball possession. A total of 24 male elite youth soccer players (age: 14.79±0.71 years; body mass: 56.02±1.41 kg; body height: 164±2.12 cm) participated in the study. Players' physical metric and technical performance data were captured using a global positioning system and video camera, respectively. A paired-samples t-test or Wilcoxon Signed-Rank Test was employed to examine differences in players' technical performance variables depending on SSGs' ball-touch rules.

Results: The results show significantly more unsuccessful passes (t=-3.48; P=0.04; d=1.92) when players were limited to two touches than when there were no pass limits. The physical metrics indicate that total distance covered (Z=-2.90; P=0.001; d=0.07), meters per minute (Z=-3.44; P=0.001; d=0.11), low-speed running (Z=-2.25; P=0.02; d=0.04) and high acceleration (Z=-1.90; P=0.05; d=0.28) were significantly higher when touches were unlimited than when they were not.

Conclusions: Soccer coaches should decide the number of touches per ball possession they allow depending on their tactical and/or physical objectives in training.