Journal of Sport and Health Science最新文献

Background: Sport climbing is becoming incredibly popular both in the general population and among athletes. No consensus exists regarding evidence-based sport-specific performance evaluation; therefore, this systematic review was aimed at analyzing determinants of sport climbing performance and evaluation methods by comparing climbers of different levels.

Methods: PubMed, Scopus, and Web of Science were searched up to December 20,2022. Studies providing the self-reported climbing ability associated with different functional outcomes in groups of climbers of contiguous performance levels were eligible.

Results: 74 studies were finally included. Various methods have been proposed to evaluate determinants of sport climbing performance. Climbing-specific assessments were able to discriminate climbers of different levels when compared to general functional tests. Test validity resulted high for climbing-specific cardiorespiratory endurance as well as muscular-strength, -endurance, and -power; similarly, reliability was good except for cardiorespiratory endurance. Climbing-specific flexibility assessment resulted in high reliability but moderate validity, whereas balance showed low validity. Considerable conflicting evidence was found regarding anthropometric characteristics.

Conclusion: The present analysis identified cardiorespiratory endurance as well as muscular-strength, -endurance, and -power as determinants of sport climbing performance. In contrast, balance, flexibility, and anthropometric characteristics seem to count less. This review also proposes an evidence-based Functional Sport Climbing test battery for assessing performance determinants, which includes tests that have been identified to be valid, reliable, and feasible. While athletes and coaches should rely on evidence-based and standardized evaluation methods, researchers may design specific large-scale trials as a resource for providing additional, homogenous, and comparable data to improve scientific evidence and professionalism in this popular sport discipline.

Background: Fat loss mainly conveys the benefits of caloric restriction for people living with type 2 diabetes. The literature is equivocal regarding whether exercise facilitates fat loss during caloric restriction. This analysis aimed to assess the dose-response effects of exercise in combination with a caloric restriction on fat mass (FM) and FM percentage (FM%) in persons with diagnosed type 2 diabetes.

Methods: In this secondary analysis of a 4-armed randomized trial, 82 persons living with type 2 diabetes were randomly allocated to the control group (CON) (n = 21), diet control (DCON) (25% caloric restriction; n = 20), diet control and exercise 3 times per week (MED) (n = 20), or diet control and exercise 6 times per week (HED) (n = 21) for 16 weeks. The primary analysis was the change in FM% points. Secondary analyses included fat-free mass and visceral adipose tissue (VAT) volume (cm³).

Results: FM% decreased compared to CON by a mean difference of -3.5% (95% confidence interval (95%CI): -5.6% to -1.4%), -6.3% (95%CI: -8.4% to -4.1%), and -8.0% (95%CI: -10.2% to -5.8%) for DCON, MED, and HED, respectively. Compared to DCON, MED, and HED decreased FM% by -2.8% (95%CI: -4.9% to -0.7%) and -4.5% (95%CI: -6.6% to -2.4%), respectively. The difference in FM% between HED and MED was -1.8% (95%CI: -3.9% to 0.4%). DCON and MED decreased fat-free mass compared to CON, whereas HED preserved fat-free mass (-0.2%; 95%CI: -2.0% to 1.7%). Compared to CON, VAT volume decreased by -666.0 cm³ (95%CI: -912.8 cm³ to -385.1 cm³), -1264.0 cm³ (95%CI: -1679.6 cm³ to -655.9 cm³), and -1786.4 cm³ (95%CI: -2264.6 cm³ to -1321.2 cm³) more for DCON, MED, and HED, respectively. HED decreased VAT volume more than DCON (-1120.4 cm³; 95%CI: -1746.6 cm³ to -639.4 cm³) while the remaining comparisons did not reveal any differences.

Conclusion: All interventions were superior in reducing FM% compared to standard care. Adding exercise to a caloric restriction was superior in reducing FM% compared to a caloric restriction alone.

Background: Residual force enhancement (rFE), defined as increased isometric force following active lengthening compared to a fixed-end isometric contraction at the same muscle length and level of activation, is present across all scales of muscle. While rFE is always present at the cellular level, often rFE "non-responders" are observed during joint-level voluntary contractions.

Methods: We compared rFE between the joint level and single fiber level (vastus lateralis biopsies) in 16 young males. In vivo voluntary knee-extensor rFE was measured by comparing steady-state isometric torque between a stretch-hold (maximal activation at 150°, stretch to 70°, hold) and a fixed-end isometric contraction, with ultrasonographic recording of vastus lateralis fascicle length (FL). Fixed-end contractions were performed at 67.5°, 70.0°, 72.5°, and 75.0°; the joint angle that most closely matched FL of the stretch-hold contraction's isometric steady-state was used to calculate rFE. The starting and ending FLs of the stretch-hold contraction were expressed as % optimal FL, determined via torque-angle relationship.

Results: In single fiber experiments, the starting and ending fiber lengths were matched relative to optimal length determined from in vivo testing, yielding an average sarcomere excursion of ∼2.2-3.4 µm. There was a greater magnitude of rFE at the single fiber (∼20%) than joint level (∼5%) (p = 0.004), with "non-responders" only observed at the joint level.

Conclusion: By comparing rFE across scales within the same participants, we show the development of the rFE non-responder phenomenon is upstream of rFE's cellular mechanisms, with rFE only lost rather than gained when scaling from single fibers to the joint level.

Background: Large Language Models (LLMs) have gained much attention and, in part, have replaced common search engines as a popular channel for obtaining information due to their contextually relevant responses. Osteoarthritis (OA) is a common topic in skeletal muscle disorders, and patients often seek information about it online. Our study evaluated the ability of 3 LLMs (ChatGPT-3.5, ChatGPT-4.0, and Perplexity) to accurately answer common OA-related queries.

Methods: We defined 6 themes (pathogenesis, risk factors, clinical presentation, diagnosis, treatment and prevention, and prognosis) based on a generalization of 25 frequently asked questions about OA. Three consultant-level orthopedic specialists independently rated the LLMs' replies on a 4-point accuracy scale. The final ratings for each response were determined using a majority consensus approach. Responses classified as "satisfactory" were evaluated for comprehensiveness on a 5-point scale.

Results: ChatGPT-4.0 demonstrated superior accuracy, with 64% of responses rated as "excellent", compared to 40% for ChatGPT-3.5 and 28% for Perplexity (Pearson's χ² test with Fisher's exact test, all p < 0.001). All 3 LLM-chatbots had high mean comprehensiveness ratings (Perplexity = 3.88; ChatGPT-4.0 = 4.56; ChatGPT-3.5 = 3.96, out of a maximum score of 5). The LLM-chatbots performed reliably across domains, except for "treatment and prevention" However, ChatGPT-4.0 still outperformed ChatGPT-3.5 and Perplexity, garnering 53.8% "excellent" ratings (Pearson's χ² test with Fisher's exact test, all p < 0.001).

Conclusion: Our findings underscore the potential of LLMs, specifically ChatGPT-4.0 and Perplexity, to deliver accurate and thorough responses to OA-related queries. Targeted correction of specific misconceptions to improve the accuracy of LLMs remains crucial.

Background: The biological mechanisms by which postdiagnosis physical activity improves disease-free survival in colorectal cancer survivors remain incompletely understood. This trial tested the hypothesis that 12 weeks of moderate-intensity aerobic exercise, when compared with a control group, would change inflammation, circulating tumor cells (CTCs), and circulating tumor DNA (ctDNA) in a manner consistent with an improved cancer prognosis.

Methods: This trial randomized Stages I-III colorectal cancer survivors to 12 weeks of home-based moderate-intensity aerobic exercise or a waitlist control group. The co-primary endpoints were high-sensitivity C-reactive protein (hs-CRP) and interleukin-6 (IL-6), secondary endpoints were soluble tumor necrosis factor-α receptor 2 (sTNFαR2) and CTCs, and the exploratory endpoint was tumor fraction quantified from ctDNA.

Results: Sixty subjects were randomized (age = 60.6 ± 10.8 years, mean ± SD; 39 (65%) females; 46 (77%) colonic primary tumor), and 59 (98%) subjects completed the study. Over 12 weeks, exercise adherence was 92% (95% confidence interval (95%CI): 86‒99). Exercise improved submaximal fitness capacity (0.36 metabolic equivalents; 95%CI: 0.05‒0.67; p = 0.025) and objectively measured moderate-to-vigorous-intensity physical activity (34.8%, 95%CI: 11.3‒63.1; p = 0.002) compared to control. Exercise did not change hs-CRP (20.9%, 95%CI: -17.1 to 76.2; p = 0.32), IL-6 (11.4%, 95%CI: -7.5 to 34.0; p = 0.25), or sTNFαR2 (-3.6%, 95%CI: -13.7 to 7.7; p = 0.52) compared to control. In the subgroup of subjects with elevated baseline hs-CRP (n = 35, 58.3%), aerobic exercise reduced hs-CRP (-35.5%, 95%CI: -55.3 to -3.8; p = 0.031). Exercise did not change CTCs (0.59 cells/mL, 95%CI: -0.33 to 1.51; p = 0.21) or tumor fraction (0.0005, 95%CI: -0.0024 to 0.0034; p = 0.73). In exploratory analyses, higher aerobic exercise adherence correlated with a reduction in CTCs (ρ = -0.37, 95%CI: -0.66 to -0.08; p = 0.013).

Conclusion: Colorectal cancer survivors achieved high adherence to a home-based moderate-intensity aerobic exercise prescription that improved fitness capacity and physical activity but did not reduce inflammation or change tumor endpoints from a liquid biopsy.

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.

Executive functions emerge throughout childhood and shape multiple cognitive and behavioral outcomes across the lifespan. Given the importance of these functions, there is considerable interest in understanding the role of environmental enrichment to support their development. The past 20 years have seen the emergence of a body of evidence around the beneficial effects of engaging in physical activity for executive functioning in children. Despite this, there are still unanswered questions, particularly about the confounding effects of the timing and dose of exercise-based interventions. During development, sensitive periods with heightened neural plasticity and sensitivity to environmental influences can offer an optimal time to introduce enrichment interventions. As such, sensitive periods for executive function could indicate an ideal time to introduce physical activity or be a potential confounder to study results if not considered. This narrative review discusses the potential presence of sensitive periods in preadolescent development where physical activity has greater benefits for executive function. Initially, we briefly review the largely parallel fields investigating the presence of sensitive periods for executive function and the effects of physical activity on executive function outcomes. We then bring together these 2 concepts to discuss the theoretical basis for developmentally sensitive periods during which children may be particularly amenable to physical activity-based interventions and offer potential ways forward to investigate this phenomenon. We hope this review will attract researchers to collaborate in the area and extend our current understanding of the development of executive functions as well as interventions like physical activity.