Sports Medicine - Open最新文献

Background: Throwing velocity is an important research topic in sports science, and it is an essential performance variable for athletes in overarm-throwing sports like baseball, team handball, water polo, softball, and cricket. The aim of the present review was to investigate the effect of specific strength training on throwing velocity for overarm throws.

Methods: The literature was analysed using the Preferred Reporting Items for Systematic reviews and Meta-analyses, searching in SPORTDiscus and MEDLINE. Seventeen studies were included in this review, and the training studies were divided into four categories: (a) overweight and underweight balls, (b) forearm loading, (c) pulley device training, and (d) strength training with a resistance band.

Results: All strength training studies with resistance band and the forearm loading categories increased the throwing velocity, varying from 3.7 to 26%. However, only half of these studies found that training was associated with a significantly higher increase versus the control group. Findings were inconsistent in other categories.

Conclusion: Based on the findings of the present review, no clear conclusion can be made on which of the specific strength training methods is best for increasing throwing velocity. However, some recommendations can be offered. Firstly, the throwing training period should be long enough (≥ 6 weeks) with a high enough workload. Throwing training with a resistance band increases throwing velocity significantly for junior and less experienced overarm-throwing athletes. Furthermore, throwing with underweighted balls of similar size will ensure a positive effect on throwing velocity. Also, throwing training with combined over- and underweighted balls can be used if the overweighted balls are carefully selected to ensure there is no negative impact on throwing kinematics and injuries. For the other categories, the results were conflicting. Furthermore, due to the low number of studies in the pulley device and forearm loading categories, more studies should be conducted to investigate their effects on throwing velocity.

Background: Resting heart rate (HR) and HR variability (HRV) are widely used parameters to assess cardiac autonomic nervous system function noninvasively. While resting assessments can be performed during sleep or after awakening, it would be relevant to know how interchangeable the results of these measurements are. This study aimed at examining the alignment between nocturnal and morning assessments during regular endurance training and in response to intensive training. A total of 24 recreational runners performed a 3-week baseline period (BL) and a 2-week overload (OL) period (Lucia's training impulse + 80%). Their running performance was assessed with a 3000-m running test after the BL and OL. The participants recorded daily their nocturnal HR and HRV (the natural logarithm of the root mean square of successive differences; LnRMSSD) with a photoplethysmography-based wrist device and performed an orthostatic test (2-min supine, 2-min standing) every morning with a chest-strap HR sensor. The HR and LnRMSSD segments that were analyzed from the nocturnal recordings included start value (SleepStart), end value (SleepEnd), first 4-h segment 30 min after detected sleep onset (Sleep4h), and full sleep time (SleepFull). The morning segments consisted of the last-minute average in both body positions. All segments were compared at BL and in response to the 3000-m test and OL.

Results: All nocturnal HR and LnRMSSD segments correlated with supine and standing segments at BL (r = 0.42 to 0.91, p < 0.05). After the 3000-m test, the HR increased and LnRMSSD decreased only in the SleepStart, Sleep4h, and SleepFull segments (p < 0.05). In response to the OL, the standing HR decreased (p < 0.01), while the LnRMSSD increased (p < 0.05) in all segments except for SleepStart. The Pearson correlations between relative changes in nocturnal and morning segments were - 0.11 to 0.72 (3000-m) and - 0.25 to 0.79 (OL). The OL response in Sleep4h HR and LnRMSSD correlated with the relative change in 3000-m time (r = 0.63, p = 0.001 and r=-0.50, p = 0.013, respectively).

Conclusions: Nocturnal and morning HR and LnRMSSD correlated moderately or highly in the majority of cases during the BL, but their responses to intensive training were not similarly aligned, especially in LnRMSSD. The nocturnal segments seemed to be sensitive to physical loading, and their responses were associated with the performance-related training responses.

Background: Recent advancements in artificial intelligence have proven their effectiveness in orthopaedic settings, especially in tasks like medical image analysis. This study compares human musculoskeletal radiologists to artificial intelligence in a novel, detailed, short, and cost-effective examination of Achilles tendon magnetic resonance images to uncover potential disparities in their reasoning approaches. Aiming to identify relationships between the structured assessment of the Achilles tendon and its function that could support injury prevention. We examined 72 athletes to investigate the link between Achilles tendon structure, as visualised in magnetic resonance images using a precise T2*-weighted gradient echo sequence with very short echo times, and its functional attributes. The acquired data were analysed using advanced artificial intelligence techniques and reviewed by radiologists. Additionally, we conducted statistical assessments to explore relationships with functional studies in four meaningful groups: dynamic strength, range of motion, muscle torque and stabilography.

Results: The results show notable linear or non-linear relationships between functional indicators and structural alterations (maximal obtained Spearman correlation coefficients ranged from 0.3 to 0.36 for radiological assessment and from 0.33 to 0.49 for artificial intelligence assessment, while maximal normalised mutual information ranged from 0.52 to 0.57 for radiological assessment and from 0.42 to 0.6 for artificial intelligence assessment). Moreover, when artificial intelligence-based magnetic resonance assessment was utilised as an input, the associations consistently proved more robust, or the count of significant relationships surpassed that derived from radiological assessment. Ultimately, utilising only structural parameters as inputs enabled us to explain up to 59% of the variance within specific functional groups.

Conclusions: This analysis revealed that structural parameters influence four key functional aspects related to the Achilles tendon. Furthermore, we found that relying solely on subjective radiologist opinions limited our ability to reason effectively, in contrast to the structured artificial intelligence assessment.

Study design: Cross-sectional studies.

Background: Research highlights the intense physiological demands of thoroughbred racing on jockeys, with elevated heart rates and substantial oxygen uptake, confirming the rigorous physical nature of the sport, however, the cardiovascular changes resulting from the physical demands of thoroughbred racing remain unexplored in Australian jockeys. Therefore, the objective of this study was to compare measures of cardiac structure and function of professional Australian jockeys to that of the general population and to determine if there are differences in heart structure and function detected using echocardiography.

Methods: Forty-six jockeys and thirty-three participants from the general population underwent two-dimensional echocardiography, which included all standard views and measurements. Each measurement was compared between groups using a Mann-Whitney U test.

Results: Groups were matched for age (jockeys (35 ± 12 years) and controls (36 ± 13 years)). Jockeys were shorter (1.64 ± 0.07 m vs. 1.75 ± 0.09 m, p < 0.001), lighter (56.5 ± 6.0 kg vs. 74.2 ± 12.9 kg, p < 0.001) and had a lower body surface area (BSA) (1.55 ± 0.17 m² vs.1.9 ± 0.2 m², p < 0.001). Jockeys had a larger absolute left ventricular (LV) end diastolic volume than the control group (120 ± 18.2 ml vs. 109.3 ± 29.0 ml, p = 0.05) which had a larger variation when indexed for BSA (78.0 ± 12.2 ml/m² vs. 57.5 ± 13.3 ml/m², p < 0.001). Jockeys demonstrated a higher LV mass index (79.4 ± 18.1 g/m² vs. 64.2 ± 15.4 g/m², p < 0.001). Left atrial volume index was larger in jockeys (33.4 ± 6.5 mL/m² vs. 26.3 ± 7.0 mL/m², p < 0.001). There were no differences in global longitudinal strain (GLS) for either group overall (-19.3 ± 3.0% vs. -19.8 ± 1.6%, p = 0.52), but 17% of the jockey group demonstrated an abnormal GLS.

Conclusions: Jockeys have adaptations to their cardiac structure and function compared to the general population. Differences could be attributed to chronic physiological demands of racing and should be considered in future research involving jockeys.

Background: Obesity and type 2 diabetes (T2D) are associated with alterations in testosterone concentrations. While evidence indicates that aerobic training can influence testosterone in healthy populations or females with hyperandrogenism, its impact in individuals with obesity or T2D remains unclear. Thus, the aim of this study was to investigate whether aerobic training can influence circulating testosterone concentrations in individuals with obesity or T2D.

Methods: EBSCOhost (CINAHL, MEDLINE, SPORTDiscus), PubMed and Embase were searched for articles published until August 2023. Eligible articles included individuals with obesity or T2D that underwent an aerobic exercise intervention with testosterone concentrations measured at baseline and post intervention. Two reviewers independently screened the seven articles included in this meta-analysis and conducted data extraction and risk of bias assessments.

Results: A total of 103 participants (62 men / 41 women) from three randomised controlled trials and four non-randomised controlled trials were included. Effect sizes were computed with random effects models. Aerobic exercise moderately increased testosterone concentrations in men (g = 0.565, 95% CI = 0.307 to 0.822, p < 0.001), but had no significant effect in women (g = -0.523, 95% CI = -1.541, 0.496, p = 0.314). Aerobic exercise had no significant effect on sex hormone-binding globulin or markers of insulin sensitivity (p > 0.05).

Conclusions: Aerobic training may be used to increase testosterone concentrations in men with obesity or T2D, but potentially has no influence in women. Given the low number of studies, further studies investigating the effect of exercise on circulating sex hormones in men and women with obesity or T2D are needed.

Background: The effects of physical activity on the development of different types of cancers have not been comprehensively studied. This nationwide, population-based cohort study investigated the effects of leisure-time physical activity (LTPA) on the development of different types of cancer in Taiwanese adults. A total of 67,890 adult participants (≥ 18 y old) from five rounds (2001, 2005, 2009, 2013, and 2017) of the Taiwan National Health Interview Survey were included. LTPA was measured as the metabolic equivalent of task (MET) expenditure per week and was classified as inactive (< 1 MET-h), low (1-7.49 MET-h), or high (≥ 7.5 MET-h). The LTPA and other covariates were collected through in-person interviews at baseline. New-onset cancer was ascertained from histopathological reports. The Fine-Gray sub-distribution method, with death as a competing risk, was used to determine the impact of LTPA on incident cancer risk.

Results: During the 844,337 person-years of follow-up, 4,435 individuals developed cancer. Compared to inactive adults, individuals engaging in high levels of LTPA (≥ 7.5 MET-h/week) were significantly associated with a reduced risk of developing cancer (adjusted hazard ratio [aHR] = 0.93; 95% confidence interval [CI] = 0.87-0.99). However, those with low levels of LTPA (1-7.49 MET-h/week) did not exhibit a significant association with a reduced risk of developing cancer (aHR = 1.00; 95% CI = 0.92-1.10). When considering specific types of cancers, participants with high levels of LTPA (≥ 7.5 MET-h/week) had a significantly lower risk of developing bladder cancer (aHR = 0.68; 95% CI = 0.47-0.99), cervical cancer (aHR = 0.48; 95% CI = 0.24-0.95), and thyroid cancer (aHR = 0.64; 95% CI = 0.44-0.93).

Conclusions: Our findings suggest that high LTPA (≥ 7.5 MET-h/week) is significantly associated with a low risk of incident bladder, cervical, and thyroid cancers.

Background: Although recent studies have increasingly focused on examining the potential benefits of creatine supplementation to improve performance in swimming events, the impact of creatine supplementation on swimming performance remains a topic of debate and controversy. A comprehensive meta-analytical review was undertaken to evaluate the effects of creatine supplementation on the performance, physiological response, and body composition among swimmers.

Methods: The research methodology adhered strictly to the guidelines outlined by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). A comprehensive search was conducted across six databases (Cochrane Library, Web of Science, Scopus, Embase, PubMed, and SPORTDiscus) until March 23, 2024. Eligible studies that investigated the impact of creatine supplementation on swimming time, physiological parameters, and body composition in swimmers were included. For the meta-analysis, a random-effects model was employed to determine the collective effect and assess variations across distinct subgroups defined by swimming time, physiological metrics, and body composition. Meta-regression analysis was conducted on datasets comprising ten or more studies. Standardized mean differences (SMD) along with their corresponding 95% confidence intervals (CI) were calculated. To evaluate the methodological rigor of the included studies, the Physiotherapy Evidence Database (PEDro) scale was utilized.

Results: The systematic review included seventeen studies with a total of 361 subjects. No significant differences were observed in the overall effect during single sprint swimming (SMD: -0.05, 95% CI: -0.26, 0.15; p = 0.61), repeated interval swimming (SMD: -0.11; 95% CI: -0.46, 0.25; p = 0.56), physiological response (SMD: 0.04, 95% CI: -0.16, 0.23; p = 0.71), and body composition (SMD: 0.18; 95% CI: -0.05, 0.41; p = 0.12) between creatine and placebo groups.

Conclusions: Creatine supplementation exhibited ineffectiveness in enhancing the performance, physiological response, and body composition among swimmers.

Background: Electrocardiograms (ECGs) in athletes commonly reveal findings related to physiologic adaptations to exercise, that may be difficult to discern from true underlying cardiovascular abnormalities. North American and European societies have published consensus statements for normal, borderline, and abnormal ECG findings for athletes, but these criteria are not based on established correlation with disease states. Additionally, data comparing ECG findings in athletes to non-athlete control subjects are lacking. Our objective was to compare the ECGs of collegiate athletes and non-athlete controls using Z-scores for digital ECG variables to better identify significant differences between the groups and to evaluate the ECG variables in athletes falling outside the normal range.

Methods: Values for 102 digital ECG variables on 7206 subjects aged 17-22 years, including 672 athletes, from Hawaii Pacific Health, University of Hawaii, and Rady Children's Hospital San Diego were obtained through retrospective review. Age and sex-specific Z-scores for ECG variables were derived from normal subjects and used to assess the range of values for specific ECG variables in young athletes. Athletes with abnormal ECGs were referred to cardiology consultation and/or echocardiogram.

Results: Athletes had slower heart rate, longer PR interval, more rightward QRS axis, longer QRS duration but shorter QTc duration, larger amplitude and area of T waves, prevalent R' waves in V1, and higher values of variables traditionally associated with left ventricular hypertrophy (LVH): amplitudes of S waves (leads V1-V2), Q waves (V6, III) and R waves (II, V5, V6). Z-scores of these ECG variables in 558 (83%) of the athletes fell within - 2.5 and 2.5 range derived from the normal population dataset, and 60 (8.9%) athletes had a Z-score outside the - 3 to 3 range. While 191 (28.4%) athletes met traditional voltage criteria for diagnosis of LVH on ECG, only 53 athletes (7.9%) had Z-scores outside the range of -2.5 to 2.5 for both S amplitude in leads V1-V2 and R amplitude in leads V5-6. Only one athlete was diagnosed with hypertrophic cardiomyopathy with a Z-score of R wave in V6 of 2.34 and T wave in V6 of -5.94.

Conclusion: The use of Z-scores derived from a normal population may provide more precise screening to define cardiac abnormalities in young athletes and reduce unnecessary secondary testing, restrictions and concern.

Background: Aging results in changes in resting state functional connectivity within key networks associated with cognition. Cardiovascular function, physical activity, sleep, and body composition may influence these age-related changes in the brain. Better understanding these associations may help clarify mechanisms related to brain aging and guide interventional strategies to reduce these changes.

Methods: In a large (n = 398) sample of healthy community dwelling older adults that were part of a larger interventional trial, we conducted cross sectional analyses of baseline data to examine the relationships between several modifiable behaviors and resting state functional connectivity within networks associated with cognition and emotional regulation. Additionally, maximal aerobic capacity, physical activity, quality of sleep, and body composition were assessed. Associations were explored both through correlation and best vs. worst group comparisons.

Results: Greater cardiovascular fitness, but not larger quantity of daily physical activity, was associated with greater functional connectivity within the Default Mode (p = 0.008 r = 0.142) and Salience Networks (p = 0.005, r = 0.152). Better sleep (greater efficiency and fewer nighttime awakenings) was also associated with greater functional connectivity within multiple networks including the Default Mode, Executive Control, and Salience Networks. When the population was split into quartiles, the highest body fat group displayed higher functional connectivity in the Dorsal Attentional Network compared to the lowest body fat percentage (p = 0.011; 95% CI - 0.0172 to - 0.0023).

Conclusion: These findings confirm and expand on previous work indicating that, in older adults, higher levels of cardiovascular fitness and better sleep quality, but not greater quantity of physical activity, total sleep time, or lower body fat percentage are associated with increased functional connectivity within key resting state networks.

Introduction: Physical inactivity and sedentary behavior both increase the risk of chronic disease and mortality. Regular participation in physical activity and reducing sedentary behavior play important roles in maintaining physical health and disease prevention.

Objective: The purpose of this study was to investigate the effect of programed walking exercise using a wearable hip exoskeleton, Bot Fit on muscle strength, muscle effort, and the kinematics of the pelvis in younger adults.

Methods: We designed three parallel experimental conditions and randomly assigned participants to one of three groups: those assigned to exercise using an interval program of Bot Fit (interval group), those who used a power program of Bot Fit (power group), and a control group who exercised without Bot Fit. A total of 45 young adults participated in 18 exercise-intervention sessions over six weeks, and all participants were assessed at two time points: before and after the 18 exercise sessions. Each assessment evaluated muscle strength, muscle effort, and the kinematics of the pelvis during walking. In addition, the number of steps, distance, energy expenditure, and heart rate for 30 min during the exercise sessions were recorded.

Results: A significant increase in the maximum voluntary contraction (MVC) of the left biceps femoris (BF) was evident in the interval group, while significant changes in the MVC of the bilateral BF were seen in the power group after Bot Fit exercise. A significant decrease of muscle effort in the right BF in the interval group and right lumbar erector spinae and bilateral BF in the power group were also observed. In addition, the symmetry index of pelvic tilt significantly improved in the interval group, and greater exercise volume and intensity in both the interval and power groups compared with the control group were confirmed as measured by the number of steps, distance, energy expenditure, and heart rate.

Conclusions: The results of this study confirmed the beneficial effect of programed walking exercise using the Bot Fit on muscle strength of trunk and lower extremities, muscle effort, and pelvic movement symmetry in younger adults. Personalized exercise programs can be provided for younger adults using various resistance or assistance modes of robotic device with the Bot Fit.

Trial registration: ClinicalTrials.gov, NCT05862077. Registered 22 March 2022, https://register.

Clinicaltrials: gov/ .