Frontiers in Sports and Active Living最新文献

This article reviews the existing literature and outlines recent advances in quantitative Magnetic Resonance Imaging (MRI) techniques for the assessment of lower extremity muscle microtrauma following a marathon. Single-modality quantitative MRI techniques include T2 mapping to assess the dynamics of muscle inflammatory edema and variability at the site of injury, Diffusion Tensor Imaging (DTI) to detect subclinical changes in muscle injury, Intravoxel Incoherent Motion (IVIM) imaging to provide simultaneous information on perfusion and diffusion in muscle tissue without the need for intravenous contrast, and Magnetic Resonance Spectroscopy (MRS) to noninvasively detect intramyocellular lipid (IMCL) content in muscle before and after marathon exercise to explain the use of fatty acids as an energy source in skeletal muscle during long-distance running. As well as Chemical Exchange Saturation Transfer (CEST) is particularly suitable for detecting changes in free creatine, pH values and lactate concentrations in muscles before and after exercise, providing a more detailed picture of muscle physiology and chemistry. These metabolic MRI methods enhance the understanding of biochemical alterations occurring in muscles pre- and post-exercise. Multimodal techniques combine different modalities to provide a comprehensive evaluation of muscle structural and functional changes. These advanced techniques aim to better assess microtrauma and guide clinical treatment, though further validation with larger studies is needed to establish their potential over traditional qualitative methods.

Introduction: Strength training (ST) is a strategy to enhance quality of life through increased strength, muscle hypertrophy, and functional capacity. Training systems are associated with manipulation of volume and intensity, generating different stimuli, such as Rest-Pause (RP) and Sarcoplasmic Stimulating Training (SST). These systems induce greater mechanical and physiological stress, leading to increased strength and muscle hypertrophy. However, the metabolic and psycho-affective effects of advanced systems in experienced practitioners remain inconclusive. The purpose of the study is to analyze the acute effects of RP, SST, and Traditional (TMS) systems on metabolic and psycho-affective responses in adult men.

Methods: This experimental crossover study assessed 15 subjects (30.38 ± 2.06 years; 88.40 ± 6.50 kg; 1.74 ± 0.07 cm) experienced in ST, evaluated under TMS, RP, and SST during flat bench press and leg press 45° exercises. Body composition, muscular strength via 1-RM testing, lactate concentration (LAC), and psycho-affective measures (Rating of Perceived Exertion-RPE; Visual Analog Scale-VAS; Feeling Scale-FS) were determined. Statistical analysis was performed using the Minitab software, with p ≤ 0.05, IC-95%).

Results: The finals results showed SST exhibited a 38.10% lower LAC concentration post-training session compared to TMS, while RP showed 37.20% lower LAC concentration than TMS post-session. Average RPE values for RP and SST were higher (8.50 ± 1.10 and 8.60 ± 0.90, respectively) than TMS (6.00 ± 1.10). VAS displayed higher average values for RP and SST (8.00 ± 2.00 and 8.00 ± 1.00, respectively) compared to TMS (5.00 ± 1.00), with affective ratings indicating positive values for TMS and values between 0 and -5 for RP (40%) and SST (60%) post-training sessions, suggesting that RP and SST induced less affective response than TMS.

Discussion: The results lead to the conclusion that manipulation of training volume and intensity led to higher RPE and pain (VAS). The data suggest that inappropriate prescription of these systems could lead to greater displeasure, leading us to hypothesize that a higher likelihood of discontinuation from strength training programs would occur, suggesting that greater repetition volumes (RP and SST) should be targeted at individuals with a higher training level.

Many normalized coaching behaviors are often abusive yet are seen by coaches and athletes as instrumental in achievement and competition. The current study was designed to extend past research and theory by subjectively exploring how and why former intercollegiate athletes identified their head coach as emotionally abusive. Twenty former intercollegiate student-athletes (M _age = 26.0 years) from nine sports participated in semi-structured interviews ranging from 65 to 189 min (M = 105.8, SD = 58). Interpretive description methodology was used with reflexive thematic analysis to generate a coherent conceptual description of the themes and shared experiences that characterized emotionally abusive coaching. The themes that associated with an athlete labeling a coach as emotionally abusive fall under two aspects of Stirling and Kerr's 2008 definition: non-contact coach behaviors and the resulting harmful outcomes experienced by the athletes. Non-contact behaviors were ones that diminished performance, neglected holistic development, and were inconsistent. The harmful effects were the negative emotional responses and dehumanization experienced by athletes. Finally, participants felt that a coach's desire for power and control over athletes explained the coach's behaviors generally. Based on these results, we put forth the conceptual claim that emotional abuse, and psychological violence more broadly, cannot be defined or identified based solely on the perpetrator's behaviors. The athlete's cognitions, perceptions, emotions, and behaviors are critical in determining whether emotional abuse occurred, and these interpretations are shaped by an athlete's existing relationship with the coach.

Introduction: Nutrition plays an integral role in optimizing football players' performance during training sessions and matches and maintaining their overall health throughout the season. This study aimed to evaluate how well the dietary practices of professional and adolescent football players in Morocco during the competitive period met international macronutrient recommendations, and to explore the relationship between their nutritional status and aerobic performance, as measured by the Yo-Yo IRL1 test.

Methods: A total of 277 footballers from Morocco's professional league, "Botola-Pro", were monitored over a seven-day (training microcycle) during the competitive period. The dietary intake was assessed through self-reported methods and 24-hour recalls. Relevant body composition was measured with bioelectrical impedance (BI), and aerobic performance was evaluated using the Yo-Yo IR test.

Results: The results indicated significant variations in performance and nutritional status across different categories and age groups. The nutritional status of the players didn't match the UEFA recommendations (p < 0.001). We found that higher intake levels of carbohydrates and proteins were positively correlated with the total distance covered by the players (p < 0.001, r = 0.63, R² = 0.4 for carbohydrates; p < 0.001, r = 0.59, R² = 0.35 for proteins). Conversely, a higher proportion of energy derived from fats in the diet was negatively correlated with the distance covered (p < 0.001, r = -0.64, R² = 0.41).

Conclusion: These findings suggest that optimizing carbohydrates and protein intake while managing fat consumption is crucial for enhancing sporting performance. This information is essential for tailoring training programs and nutritional regimens based on the competition level.

Introduction: The sport of cycling has witnessed phenomenal growth over the past decade. Globally, over 200 million television hours across five continents watched the recent inaugural World Championships in Glasgow, in 2023. The Union Cycliste Internationale (UCI), the world cycling governing body, has highlighted its mission to "promote and support research in cycling epidemiology and medicine, especially for the benefit of lesser-known disciplines" within its 2030 Agenda. This paper outlines a proposed protocol to conduct a systematic review that comprehensively analyses and synthesises the existing literature about cycling-related injuries and illness across all competitive disciplines.

Methods: The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines will be followed through each stage of this systematic review. Cycling is an umbrella term used for many individual disciplines. Investigation of all types of injuries and/or illnesses sustained during training and/or competition among competitive athletes across all disciplines will be included in this review. A computerised, systematic literature search will be conducted in electronic databases MEDLINE, Scopus, Embase, and Cochrane Library. Independent screening by two reviewers in a two-step process: title/abstract screening followed by full-text review. The reference lists of included articles will be searched to identify any other potentially relevant articles. Narrative synthesis and tabular/charted presentation of the extracted data will be included.

Discussion: This protocol paper outlines the methodology to conduct a systematic review of injuries and illness across all competitive cycling disciplines. The aims of outlining this systematic review protocol are to aid research transparency, help reduce publication bias, prevent selective publication, and prevent the selective reporting of results. Future systematic reviews based on the proposed protocol will summarise the known prevalence, incidences, locations and burden of injury and illness across the sport of cycling.

Trial registration: This study has been registered with the PROSPERO International Prospective Register of Systematic Reviews (registration number CRD42024502703).

Introduction: This study explores the integration of financial stability regulation in professional soccer within the framework of sport governance, focusing on the German context. The research examines how financial regulations influence key governance principles such as accountability, transparency, and sustainability, while also addressing the challenges posed by the dynamic nature of professional soccer.

Methods: A qualitative methodology was employed, using focus group discussions with nine experts, including representatives from soccer clubs, auditing firms and other relevant stakeholders. The discussions aimed to capture diverse perspectives on the impact of financial stability regulation on governance practices within the German soccer league and clubs.

Results: The findings reveal that financial stability regulation is effective in promoting financial discipline and accountability at both league and club levels. However, the study also identifies challenges, such as the need for greater harmonization of regulatory frameworks across different levels of professional soccer and the potential benefits of implementing incentive mechanisms within the financial stability regulation to improve governance at the league and club levels.

Discussion: The study underscores the importance of a multi-dimensional approach to financial stability regulation, considering political, systemic, and organizational dimensions. It highlights the potential for improving governance through the adoption of independent governance models and more practical applications of governance principles. Future research could further explore these areas, offering insights that could enhance the effectiveness of financial regulation in professional soccer and potentially other sport contexts.

Introduction: This observational study investigated: (1) potential changes in female football players' in-season training load, intensity and physical performance, and (2) if in-season accumulated training load, intensity, or their progression are associated to changes in physical performance.

Methods: Thirty-five national level female players (∼21 years, n = 35) from three top-teams of the Finnish national league participated. Players performed tests at the beginning and at the end of the 27-week in-season. Tests were: 30-m sprint, countermovement jump (CMJ) and 1,200-m shuttle run, used to calculate maximal aerobic speed (MAS). Players' external and internal training load and intensity were monitored in all on-field training sessions and official matches (3,941 data samples) using Polar Team Pro system.

Results: Training load decreased towards the end of the in-season (p < 0.05), but intensity remained stable. No changes in physical performance test results occurred from before to after in-season tests at a group level. Change of CMJ correlated negatively with accumulated training load, intensity and progression of total distance (TD) and low-intensity running distance (LIRD) (r = -0.398 to -0.599, p < 0.05). Instead, development of MAS correlated positively with progression of TD and LIRD intensities (r = 0.594 and 0.503, p < 0.05). Development of both CMJ and MAS correlated positively with intensity progression of very-high-intensity running distance (VHIRD) and number of accelerations and decelerations (r = 0.454-0.588, p < 0.05).

Discussion: Reduced training load over the in-season is not detrimental for players' physical performance when training intensity progressively increases. Intensity progression of VHIRD, moderate- and high-intensity accelerations and decelerations are indicators of both MAS and CMJ development, respectively.

Objective: Minimum muscle oxygen saturation (SmO₂min) measured via near-infrared spectroscopy (NIRS) is a common measure during incremental exercise testing (IET). Our objective was to determine the effects of pre-to-post endurance training on SmO₂min (ΔSmO₂min) during an IET, using a meta-analysis.

Data sources: MEDLINE, EMBASE, and SPORTDiscus.

Study selection: Studies including healthy individuals had to meet the following criteria: (1) endurance training intervention; (2) peripheral muscle NIRS; (3) incremental exercise test pre/post training; (4) SmO₂ or analogous saturation parameter measured.

Analysis: A PEDro scale was used for risk of bias analysis. A random effect meta-analysis model was used to synthesize the effect of training on ΔSmO₂min in individual studies. Statistical heterogeneity was quantified using I² statistic. A meta-regression was used to estimate the effect of training on the relationship between peak cycling power output (Wpeak), peak pulmonary oxygen uptake (V˙O₂peak), and ΔSmO₂min. A mixed-effect model was used to estimate categorical variables.

Results: Five studies met the inclusion criteria. No difference in SmO₂min was detected following training pre- and post-intervention IETs. A trend for an effect of training on the relationship between Wpeak and ΔSmO₂min was observed (p = 0.06).

Conclusion: This meta-analysis showed no effects of endurance training on SmO₂min during an IET. Our results showed a trend for an effect of training on the relationship between Wpeak and ΔSmO₂min, with no effect for V˙O₂peak and ΔSmO₂min. It is possible that SmO₂min is not affected by endurance training, and may be used as a physiological marker for improvements in submaximal performance rather than at peak.

Sprint performance is a critical factor in soccer. While previous studies have extensively explored the biomechanical, physiological, and metabolic determinants of sprinting, the impact of anthropometric variables in team sports contexts, especially soccer, remains underexplored. This study aims to investigate the influence of anthropometric and mechanical variables on sprint performance in young soccer players. Fifty-eight young soccer players were evaluated in anthropometry and a 30-meter (m) sprint using radar technology. Split times in 5, 15, and 30 m were determined, in addition to the assessment of the force-velocity profile proposed by Morin and Samozino. Results: Key anthropometric variables associated with improved sprint performance included lower-limb muscle mass at distances 5 and 15 m (R ² = 0.08 and R ² = 0.09, respectively, both with small effects). Additionally, body composition, particularly a lower % body fat, was crucial across all sprint distances (ES: large). Among the mechanical variables, max power (R ² = 0.997, ES: large) and maximum velocity (R ² = 0.553, ES: large) are the mechanical variables that were most strongly associated with sprint performance over distances greater than 30 m. Soccer coaches, athletic trainers, and strength and conditioning specialists working with young athletes can apply the findings of this study to their training programming.