Journal of Sports Medicine and Physical Fitness最新文献

Background: Physical activity (PA) improves health and quality of life, while providing an effective coping strategy against burnout. This study assessed PA levels among medical students and junior doctors in Malta, exploring demographic differences and relationships with anxiety, energy drink/coffee consumption, and career progression, addressing a gap in the literature.

Methods: Two hundred twenty-nine participants (161 medical students; 68 foundation year doctors; mean age=22.90 years) completed an online questionnaire including demographic data, standardized measures of PA (GLTEQ) and anxiety (GAD-7) and questions on energy drink/coffee consumption and career progression.

Results: Results revealed a significant negative relationship between PA and age, rs(227)=-0.14, P=0.04. Males carried out more PA (OR=1.82, 95% CI, 1.12 to 2.94) than females (U=4671.00, z=-2.42, P=0.02); this gender difference in PA was present in medical students (P=0.01) not junior doctors (P=0.75). Male junior doctors were less anxious than females (U=319.00, z=-2.32, P=0.02); no significant gender difference in anxiety was revealed in medical students (P=0.76). No significant correlation was found between PA and anxiety (P=0.41) or energy drink consumption (P=0.81, 1.00). No difference in PA levels was revealed between medical students and junior doctors (P=0.09).

Conclusions: Further research is needed to compare PA levels between medical and general populations. The findings underscore the importance of including PA in medical curricula for students'/doctors' wellbeing and for effective lifestyle advice.

Background: Although high muscle oxygenation dynamics in active muscles are expected to decrease cardiac workload and ventilation associated with carbon dioxide excretion at an exercise at equivalent peak oxygen uptake (VO2) loads in the whole body, these relationships remain unclear. The aim of this study was to investigate whether high muscle oxygenation dynamics contribute to reduced cardiac workload and ventilation during exercise.

Methods: Twenty-three healthy young males were enrolled in this cross-sectional study and divided into two groups: the low muscle oxygenation dynamics group (N.=11) and the high muscle oxygenation dynamics group (N.=12), based on the change in muscle oxygen saturation (SmO2) in the right vastus lateralis from rest to peak VO2. All participants underwent cardiopulmonary exercise testing to assess the double product, cardiac workload, carbon dioxide production (VCO2), and expiratory minute volume as ventilation parameters associated with carbon dioxide excretion.

Results: Linear mixed-effect models with double product, VCO2/body mass or expiratory minute volume/body mass as the dependent variable, individual as random effects, and the group and metabolic equivalents (METs) as fixed effects revealed significant interactions between the group and METs (all P<0.001). Multiple comparison results demonstrated that the double product, VCO2/body mass at 5-8 METs, and expiratory minute volume/body mass at 6-8 METs were significantly lower in the group with high muscle oxygenation dynamics than in the group with low muscle oxygenation dynamics.

Conclusions: High muscle oxygenation dynamics contribute to reduced cardiac workload and ventilation associated with carbon dioxide excretion during exercise.

Background: Wearing a mandibular repositioning dental splint may enhance ventilatory function and exercise performance. We aim to analyze the performance and the biophysical effects of wearing an intraoral splint with mandibular repositioning when running until exhaustion at moderate intensity.

Methods: Sixteen trained male runners completed a crossover randomized controlled study to evaluate the effects of two intraoral splints (with and without mandibular forward repositioning) on performance, ventilatory and bioenergetic profiles during running until exhaustion at the velocity corresponding to the anaerobic threshold. Ventilatory variables were analyzed at different running time-points, and a paired samples t-test was employed to compare the experimental conditions across all evaluated variables.

Results: The splint with mandibular forward repositioning facilitated ~12% longer running than the splint without mandibular repositioning. Oxygen uptake was the sole ventilatory variable demonstrating a higher value across all the analyzed running time-points when the mandible was advanced (10^th min, 58.1±9.4 vs. 55.3±9.8; 10 min before the end, 57.7±8.7 vs. 55.3±9.1; and at the end of the exercise, 57.2±8.2 vs. 54.2±9.0 mL∙kg^-1∙min^-1; P≤0.05). The splint with mandibular forward repositioning also elicited a lower rate of perceived exertion (17.1±0.77 vs. 17.4±0.63, P=0.05) and higher aerobic contribution (2611±708 vs. 2212±640 kJ), overall energy spent (2633±708 vs. 2232±642 kJ) and exercise energy cost (0.28±0.05 vs. 0.26±0.05 kJ∙m-1, P≤0.005).

Conclusions: The mandibular forward repositioning elicited a marked improvement in moderate intensity performance, with beneficial physiological and perceived effects.

Background: Exercise intensity is commonly determined using maximal heart rate and maximal oxygen uptake. However, blood lactate levels at different exercise intensities are considered more sensitive biomarkers of endurance performance than maximal oxygen uptake. This study evaluated the validity of exercise intensity determined by blood lactate levels during running and determine the dynamics of blood glucose and β-hydroxybutyrate levels during high- and low-intensity running exercise.

Methods: Exercise intensities for 12 participants were determined using the lactate curve test. Each participant performed four running tests: low-intensity 30-min, high-intensity 30-min, and low-intensity 60-min running, and no-running (control) tests, with intervals of 1 day to 2 weeks. Blood glucose and β-hydroxybutyrate levels were measured using fingertip puncture blood sampling before and every 30 min (up to 240 min) after the start of running.

Results: Blood glucose levels increased significantly immediately after high-intensity 30-min running test compared to the 0-time point. Blood glucose levels decreased to similar levels as that in the 0-min time point 30 min after the 30-min running test. β-hydroxybutyrate levels increased significantly every 30 min after the 150-min time point compared to the levels in the 0-min time point in the high-intensity 30-min and low-intensity 60-min running tests.

Conclusions: Using blood lactate measurements obtained from a simple device, we established high-intensity exercise conditions producing transient post-exercise blood glucose increases. Changes in glucose and β-hydroxybutyrate levels reflected energy metabolism shifts across exercise conditions. Further investigation of additional metabolic indicators will help clarify energy metabolism mechanisms at varying exercise intensities.

Background: This study explored the perceptions of talent scouts regarding the attributes they consider essential when identifying talented youth soccer players.

Methods: This qualitative study used a pragmatic research paradigm. The sample comprised nine scouts (mean age: 50.12±9.33 years) who were interviewed. A semi-structured interview guide was used to collect data. Interview transcripts were analysed using thematic analysis.

Results: Four main themes and 11 sub-themes emerged from the interview transcripts: 1) technical attributes (i.e., first touch, dribbling, passing and finishing); 2) physical attributes (i.e., height, speed and endurance); 3) psychosocial attributes (i.e., discipline and coachability); and 4) tactical attributes (decision-making and game sense and awareness).

Conclusions: These results could help soccer coaches determine what qualities prospective talented players should have to improve their chances of getting selected for future opportunities, and thereby direct training for talent development initiatives.

Background: This study analyzed the impact of a 6-week joint-specific flywheel-based resistance training program on serve velocity (SV) and serve accuracy (SA) in junior tennis players.

Methods: Fourteen participants were assigned to either an experimental group (FG; N.=7) training with an inertial conical pulley or a control group (CG; N.=7). SV, SA, one-handed and two-handed overhead medicine ball throws (MBT) were measured preintervention, at 3 weeks, and at 6 weeks.

Results: A large main effect of time (F=5.371, P=0.012, η²=0.309) and nonsignificant group- by-time interaction (F=2.102, P=0.144, η²=0.149) was found in SV. The FG demonstrated significant increases in SV from pretest to intertest (7.1 km·h-1, 4.5%, P=0.023, ES=1.5) and from pretest to posttest (7.3 km·h^-1, 4.7%, P=0.035, ES=1.5). No changes in SV were observed in the CG. SA and MBT did not show significant changes over time in FG or CG.

Conclusions: These findings suggest that incorporating flywheel-based joint-specific exercises into training programs positively affects SV without SA impairments in junior tennis players within a relatively short timeframe. Coaches can integrate similar layouts into training to optimize player performance.

Human movement, in its synergistic, functional, and stabilizing nature, necessitates a balance of muscle length and strength between the muscles surrounding a joint. This balance, known as muscle balance, ensures optimal joint function during movement. Using a bibliography that can be linked to indexed literature, this article has as its strength the correlative analysis between gestural repetitiveness in soccer, related to players' roles on the field on the playing field that result in dysfunctional postural frameworks with increased risk factors for lower extremity injuries. Soccer, characterized by rapid changes of direction, accelerations, decelerations, twisting motions, and cutting maneuvers often performed with a dominant limb can contribute to the development of asymmetries, lateralization, and postural/dysfunctional patterns. These patterns could increase the risk of injury to the musculoskeletal system, particularly during the return-to-sport process after an injury. In contact/collision sports like soccer, asymmetrical imbalances within the lumbo-pelvic-hip complex have been linked to dysfunctional states that affect lower limb alignment. This can have clinical implications, manifesting as knee pain, low back pain, groin injuries, or adductor injuries. Additionally, rotational deficits at the hip have been identified as predictors of ACL and femoroacetabular impingement (FAI) injuries. To address these issues, a screening process to identify muscle imbalances and assess movement quality should be integrated into both preseason and in-season training programs, with regular follow-ups. Compensatory training tailored to the specific roles players occupy on the field can be effective in reducing asymmetries and mitigating the risk factors associated with musculoskeletal disorders frequently seen in soccer.

Background: Suicide is one of the leading causes of premature death. Prevalence of suicidal thoughts in the general adult population is approximately 4%, with lifetime prevalence of 5.6%, and suicidal attempts of 2.7%. No data are available on endurance runners (ER) and ultra-endurance runners (UER).

Methods: Prospective cohort study of ER (distance of ≥21.1 km-42.2 km) and UER (≥42.2 km), collecting self-reported data on biometrics, social, psychological, medical, and training history. Suicidal risk was assessed via the Patient Health Questionnaire (PHQ-9) and open questions. Statistical analysis included descriptive, predictive techniques, and regression analysis.

Results: A total of N.=601 runners participated in the study (female N.=222; male N.=379; mean age [standard deviation (SD)] 42.8 (10.1) years). Suicidal thoughts were present in 8.0%, with a lifetime prevalence of 14.1% (P<0.001). Previous suicidal attempts occurred in 2%. Associated factors for suicidal thoughts included previous diagnosis of depression (P<0.001), anxiety (P=0.015), age (P=0.013), and participating in fewer (<9) competitions per year (P=0.026). Associated factors of lifetime risk of suicidal thoughts included previous diagnoses of depression (P<0.001) and age (P=0.015). Runners aged less <30 years of age presented with a higher risk of suicide (P<0.001) than older runners. Associated factors for previous suicidal attempts included previous diagnosis of depression (P=0.01) and stress (P=0.028).

Conclusions: We present novel data on prevalence of suicidal thoughts in ER/UER, which were 2-2.5-fold higher than in the general population. Creating awareness among athletes, families, coaches, medical teams, and race organizers and providing education, screening and access to appropriate support are important to reduce the burden of suicide in this sport.