Journal of Sport and Health Science最新文献

Background: Resistance exercise leads to improved muscle function and metabolic homeostasis. Yet how circadian rhythm impacts exercise outcomes and its molecular transduction remains elusive.

Methods: Human volunteers were subjected to 4 weeks of resistance training protocols at different times of day to assess training outcomes and their associations with myokine irisin. Based on rhythmicity of Fibronectin type III domain containing 5 (FNDC5/irisin), we trained wild type and FNDC5 knockout mice at late active phase (high FNDC5/irisin level) or late rest phase (low FNDC5/irisin level) to analyze exercise benefits on muscle function and metabolic homeostasis. Molecular analysis was performed to understand the regulatory mechanisms of FNDC5 rhythmicity and downstream signaling transduction in skeletal muscle.

Results: In this study, we showed that regular resistance exercises performed at different times of day resulted in distinct training outcomes in humans, including exercise benefits and altered plasma metabolomics. We found that muscle FNDC5/irisin levels exhibit rhythmicity. Consistent with human data, compared to late rest phase (low irisin level), mice trained chronically at late active phase (high irisin level) gained more muscle capacity along with improved metabolic fitness and metabolomics/lipidomics profiles under a high-fat diet, whereas these differences were lost in FNDC5 knockout mice. Mechanistically, Basic helix-loop-helix ARNT like 1 (BMAL1) and Peroxisome proliferative activated receptor, gamma, coactivator 1 alpha 4 (PGC1α4) induce FNDC5/irisin transcription and rhythmicity, and the signaling is transduced via αV integrin in muscle.

Conclusion: Together, our results offered novel insights that exercise performed at distinct times of day determines training outcomes and metabolic benefits through the rhythmic regulation of the BMAL1/PGC1α4-FNDC5/irisin axis.

Background: There is a lack of research examining the interplay between objectively measured physical activity volume and intensity with life expectancy.

Methods: Individuals from UK Biobank with wrist-worn accelerometer data were included. The average acceleration and intensity gradient were extracted to describe the physical activity volume and intensity profile. Mortality data were obtained from national registries. Adjusted life expectancies were estimated using parametric flexible survival models.

Results: 40,953 (57.1%) women (median age = 61.9 years) and 30,820 (42.9%) men (63.1 years) were included. Over a median follow-up of 6.9 years, there were 1719 (2.4%) deaths (733 in women; 986 in men). At 60 years, life expectancy was progressively longer for higher physical activity volume and intensity profiles, reaching 95.6 years in women and 94.5 years in men at the 90th centile for both volume and intensity, corresponding to 3.4 (95% confidence interval (95%CI): 2.4-4.4) additional years in women and 4.6 (95%CI: 3.6-5.6) additional years in men compared to those at the 10th centiles. An additional 10-min or 30-min daily brisk walk was associated with 0.9 (95%CI: 0.5-1.3) and 1.4 (95%CI: 0.9-1.9) years longer life expectancy, respectively, in inactive women; and 1.4 (95%CI: 1.0-1.8) and 2.5 (95%CI: 1.9-3.1) years in inactive men.

Conclusion: Higher physical activity volumes were associated with longer life expectancy, with a higher physical activity intensity profile further adding to a longer life. Adding as little as a 10-min brisk walk to daily activity patterns may result in a meaningful benefit to life expectancy.

Background: The development of computer vision technology has enabled the use of markerless movement tracking for biomechanical analysis. Recent research has reported the feasibility of markerless systems in motion analysis but has yet to fully explore their utility for capturing faster movements, such as running. Applied studies using markerless systems in clinical and sports settings are still lacking. Thus, the present study compared running biomechanics estimated by marker-based and markerless systems. Given running speed not only affects sports performance but is also associated with clinical injury prevention, diagnosis, and rehabilitation, we aimed to investigate the effects of speed on the comparison of estimated lower extremity joint moments and powers between markerless and marker-based technologies during treadmill running as a concurrent validating study.

Methods: Kinematic data from marker-based/markerless technologies were collected, along with ground reaction force data, from 16 young adults running on an instrumented treadmill at 3 speeds: 2.24 m/s, 2.91 m/s, and 3.58 m/s (5.0 miles/h, 6.5 miles/h, and 8.0 miles/h). Sagittal plane moments and powers of the hip, knee, and ankle were calculated by inverse dynamic methods. Time series analysis and statistical parametric mapping were used to determine system differences.

Results: Compared to the marker-based system, the markerless system estimated increased lower extremity joint kinetics with faster speed during the swing phase in most cases.

Conclusion: Despite the promising application of markerless technology in clinical settings, systematic markerless overestimation requires focused attention. Based on segment pose estimations, the centers of mass estimated by markerless technologies were farther away from the relevant distal joint centers, which led to greater joint moments and powers estimates by markerless vs. marker-based systems. The differences were amplified by running speed.

Background: Evidence on the health benefits of occupational physical activity (OPA) is inconclusive. We examined the associations of baseline OPA and OPA changes with all-cause, cardiovascular disease (CVD), and cancer mortality and survival times.

Methods: This study included prospective and longitudinal data from the MJ Cohort, comprising adults over 18 years recruited in 1998-2016, 349,248 adults (177,314 women) with baseline OPA, of whom 105,715 (52,503 women) had 2 OPA measures at 6.3 ± 4.2 years (mean ± SD) apart. Exposures were baseline OPA, OPA changes, and baseline leisure-time physical activity.

Results: Over a mean mortality follow-up of 16.2 ± 5.5 years for men and 16.4 ± 5.4 years for women, 11,696 deaths (2033 of CVD and 4631 of cancer causes) in men and 8980 deaths (1475 of CVD and 3689 of cancer causes) in women occurred. Combined moderately heavy/heavy baseline OPA was beneficially associated with all-cause mortality in men (multivariable-adjusted hazard ratio (HR) = 0.93, 95% confidence interval (95%CI): 0.89-0.98 compared to light OPA) and women (HR = 0.86, 95%CI: 0.79-0.93). Over a mean mortality follow-up of 12.5 ± 4.6 years for men and 12.6 ± 4.6 years for women, OPA decreases in men were detrimentally associated (HR = 1.16, 95%CI: 1.01-1.33) with all-cause mortality, while OPA increases in women were beneficially (HR = 0.83, 95%CI: 0.70-0.97) associated with the same outcome. Baseline or changes in OPA showed no associations with CVD or cancer mortality.

Conclusion: Higher baseline OPA was beneficially associated with all-cause mortality risk in both men and women. Our longitudinal OPA analyses partly confirmed the prospective findings, with some discordance between sex groups.

Background: Impairments in hamstring strength, flexibility, and morphology have been associated with altered knee biomechanics, pain, and function. Determining the presence of these impairments in individuals with gradual-onset knee disorders is important and may indicate targets for assessment and rehabilitation. This systematic review aimed to synthesize the literature to determine the presence of impairments in hamstring strength, flexibility, and morphology in individuals with gradual-onset knee disorders.

Methods: Five databases (MEDLINE, Embase, CINAHL, SPORTDiscus, and Web of Science) were searched from inception to September 2022. Only studies comparing hamstring outcomes (e.g., strength, flexibility, and/or morphology) between individuals with gradual-onset knee disorders and their unaffected limbs or pain-free controls were included. Meta-analyses for each knee disorder were performed. Outcome-level certainty was assessed using the Grading of Recommendations Assessment, Development, and Evaluation, and evidence gap maps were created.

Results: Seventy-nine studies across 4 different gradual-onset knee disorders (i.e., knee osteoarthritis (OA), patellofemoral pain (PFP), chondromalacia patellae, and patellar tendinopathy) were included. Individuals with knee OA presented with reduced hamstring strength compared to pain-free controls during isometric (standard mean difference (SMD) = -0.76, 95% confidence interval (95%CI) : -1.32 to -0.21) and concentric contractions (SMD = -0.97, 95%CI : -1.49 to -0.45). Individuals with PFP presented with reduced hamstring strength compared to pain-free controls during isometric (SMD = -0.48, 95%CI : -0.82 to -0.14), concentric (SMD = -1.07, 95%CI : -2.08 to -0.06), and eccentric contractions (SMD = -0.59, 95%CI : -0.97 to -0.21). No differences were observed in individuals with patellar tendinopathy. Individuals with PFP presented with reduced hamstring flexibility when compared to pain-free controls (SMD = -0.76, 95%CI : -1.15 to -0.36). Evidence gap maps identified insufficient evidence for chondromalacia patellae and hamstring morphology across all gradual-onset knee disorders.

Conclusion: Our findings suggest that assessing and targeting impairments in hamstring strength and flexibility during rehabilitation may be recommended for individuals with knee OA or PFP.

Background: Hemodialysis (HD) per se is a risk factor for thrombosis. Considering the growing body of evidence on blood-flow restriction (BFR) exercise in HD patients, identification of possible risk factors related to the prothrombotic agent D-dimer is required for the safety and feasibility of this training model. The aim of the present study was to identify risk factors associated with higher D-dimer levels and to determine the acute effect of resistance exercise (RE) with BFR on this molecule.

Methods: Two hundred and six HD patients volunteered for this study (all with a glomerular filtration rate of <15 mL/min/1.73 m²). The RE + BFR session consisted of 50% arterial occlusion pressure during 50 min sessions of HD (intradialytic exercise). RE repetitions included concentric and eccentric lifting phases (each lasting 2 s) and were supervised by a strength and conditioning specialist.

Results: Several variables were associated with elevated levels of D-dimer, including higher blood glucose, citrate use, recent cardiovascular events, recent intercurrents, higher inflammatory status, catheter as vascular access, older patients (>70 years old), and HD vintage. Furthermore, RE + BFR significantly increases D-dimer after 4 h. Patients with borderline baseline D-dimer levels (400-490 ng/mL) displayed increased risk of elevating D-dimer over the normal range (≥500 ng/mL).

Conclusion: These results identified factors associated with a heightened prothrombotic state and may assist in the screening process for HD patients who wish to undergo RE + BFR. D-dimer and/or other fibrinolysis factors should be assessed at baseline and throughout the protocol as a precautionary measure to maximize safety during RE + BFR.

Background: Sports medicine (injury and illnesses) requires distinct coding systems because the International Classification of Diseases is insufficient for sports medicine coding. The Orchard Sports Injury and Illness Classification System (OSIICS) is one of two sports medicine coding systems recommended by the International Olympic Committee. Regular updates of coding systems are required.

Methods: For Version 15, updates for mental health conditions in athletes, sports cardiology, concussion sub-types, infectious diseases, and skin and eye conditions were considered particularly important.

Results: Recommended codes were added from a recent International Olympic Committee consensus statement on mental health conditions in athletes. Two landmark sports cardiology papers were used to update a more comprehensive list of sports cardiology codes. Rugby union protocols on head injury assessment were used to create additional concussion codes.

Conclusion: It is planned that OSIICS Version 15 will be translated into multiple new languages in a timely fashion to facilitate international accessibility. The large number of recently published sport-specific and discipline-specific consensus statements on athlete surveillance warrant regular updating of OSIICS.

Background: Acute lateral ankle sprains (ALAS) are associated with long-term impairments and instability tied to altered neural excitability. Arthrogenic muscle inhibition (AMI) has been observed in this population; however, relationships with injury-related impairments are unclear, potentially due to the resting, prone position in which AMI is typically measured. Assessing AMI during bipedal stance may provide a better understanding of this relationship.

Methods: AMI was assessed in 38 young adults (19 ALAS within 72 h of injury: 10 males, 21.4 ± 2.7 years; 19 healthy controls: 10 males, 21.9 ± 2.2 years; mean ± SD) using the Hoffmann reflex (H-reflex) during bipedal stance. Electrical stimulation was administered to identify the maximal H-reflex (H_max) and maximal motor response (M_max) from the soleus, fibularis longus, and tibialis anterior muscles. The primary outcome measure was the H_max/M_max ratio. Secondary outcomes included acute symptoms (pain and swelling), postural control during bipedal stance, and self-reported function.

Results: No significant group-by-limb interactions were observed for any muscle. However, a significant group main effect was observed in the soleus muscle (F_(1,35) = 6.82, p = 0.013), indicating significantly lower H_max/M_max ratios following ALAS (0.38 ± 0.20) compared to healthy controls (0.53 ± 0.16). Furthermore, lower H_max/M_max ratios in the soleus significantly correlated with acute symptoms and self-reported function but not with postural control.

Conclusion: This study supports previous evidence of AMI in patients with ALAS, providing insight into neurophysiologic impacts of musculoskeletal injury. Our results suggest that assessing AMI in a standing position following acute injury may provide valuable insight into how AMI develops and guide potential therapeutic options to curb and offset the formation of joint instability.