Journal of Sport and Health Science最新文献

Background: Higher accelerometer-assessed volume and intensity of physical activity (PA) have been associated with a longer life expectancy but can be difficult to translate into recommended doses of PA. We aimed to: (a) improve interpretability by producing UK Biobank age-referenced centiles for PA volume and intensity; (b) inform public-health messaging by examining how adding recommended quantities of moderate and vigorous PA affect PA volume and intensity.

Methods: 92,480 UK Biobank participants aged 43-80 years with wrist-worn accelerometer data were included. Average acceleration and intensity gradient were derived as proxies for PA volume and intensity. We generated sex-specific centile curves using Generalized Additive Models for Location Scale and Shape (GAMLSS) and modeled the effect of adding moderate (walking) or vigorous (running) activity on the combined change in the volume and intensity centiles (change in PA profile).

Results: In men, volume was lower as age increased while intensity was lower after age 55; in women, both volume and intensity were lower as age increased. Adding 150 min of moderate PA weekly (5 × 30 min walking) increased the PA profile by 4 percentage points. Defining moderate PA as brisk walking approximately doubled the increase (9 percentage points) while 75 min of vigorous PA weekly (5 × 15 min running) trebled the increase (13 percentage points).

Conclusion: These UK Biobank reference centiles provide a benchmark for interpretation of accelerometer data. Application of our translational methods demonstrate that meeting PA guidelines through shorter duration vigorous activity is more beneficial to the PA profile (volume and intensity) than longer duration moderate activity.

Purpose: This study aimed to evaluate the relationship between peak tibial acceleration and peak ankle joint contact forces in response to stride length manipulation during level-ground running.

Methods: Twenty-seven physically active participants ran 10 trials at preferred speed in each of 5 stride length conditions: preferred, ±5 %, and ±10 % of preferred stride length. Motion capture, force platform, and tibial acceleration data were directly measured, and ankle joint contact forces were estimated using an inverse-dynamics-based static optimization routine.

Results: In general, peak axial tibial accelerations (p < 0.001) as well as axial (p < 0.001) and resultant (p < 0.001) ankle joint contact forces increased with stride length. When averaged within the 10 strides of each stride condition, moderate positive correlations were observed between peak axial acceleration and joint contact force (r = 0.49) as well as peak resultant acceleration and joint contact force (r = 0.51). However, 37% of participants illustrated either no relationship or negative correlations. Only weak correlations across participants existed between peak axial acceleration and joint contact force (r = 0.12) as well as peak resultant acceleration and ankle joint contact force (r = 0.18) when examined on a step-by-step basis.

Conclusion: These results suggest that tibial acceleration should not be used as a surrogate for ankle joint contact force on a step-by-step basis in response to stride length manipulations during level-ground running. A 10-step averaged tibial acceleration metric may be useful for some runners, but an initial laboratory assessment would be required to identify these individuals.

Background: Deficits in quadriceps strength of the injured leg have been observed in patients following anterior cruciate ligament (ACL) reconstructions and may contribute to ACL re-injury risk. Single-leg forward hopping is a widely used task for assessing knee function in patients following ACL reconstructions as it has been shown not to be particularly challenging to the knee. This study aimed to quantify the effect of decreased quadriceps strength induced by a fatigue protocol on hopping performance and lower limb mechanics in single-leg forward, vertical, and backward hopping.

Methods: Thirty-four injury-free participants performed single-leg forward, vertical, and backward hopping on both legs pre- and post-fatigue, with 1 leg experiencing a fatigue protocol. Peak moments, power, and work of hip, knee, and ankle joints were quantified during the jumping phase. Hopping performance and bilateral asymmetries in performance were assessed.

Results: Single-leg backward hopping demonstrated the greatest knee moments, power, and work compared to forward and vertical hopping, regardless of leg and fatigue. Fatigue protocol resulted in significantly less knee moments, power, and work, and decreased performance of the fatigued leg among all tasks. Bilateral symmetries in hopping performance decreased in post-fatigue, with the greatest decrease in backward hopping.

Conclusion: The greater sensitivity of the backward hopping to detect quadriceps fatigue suggests it may act as a better or at least an additional metric to evaluate quadriceps strength deficits. The findings may contribute to the development of a clinically applicable and valid strength assessment to monitor the rehabilitation progress in patients following ACL reconstructions.

Background: Guidelines recommend that adolescents should accumulate an average of 60 min per day of moderate-to-vigorous physical activity (MVPA). However, using only this cut-off could hide important information. For instance, from a population-level point of view, increasing physical activity for those with no or low physical activity could provide more health benefits than increasing physical activity for those with intermediate levels. Also, including a more sensitive cut-point of ≥1 days per week could be an additional strategy for identifying those with low access/opportunities for physical activity practice. Thus, the current study aims to estimate the prevalence of ≥60 min of MVPA ≥1 days per week among adolescents globally, and to describe any relevant gender inequalities.

Methods: We used representative datasets from 146 countries/territories collected between 2003 and 2019. MVPA was self-reported. Participants were grouped into younger (≤14 years old) and older (>14 years old) adolescents. Crude Poisson regression models were used to identify the relative differences in ≥60 min of MVPA ≥1 days per week between boys and girls, and random-effects meta-analysis models were used to identify the pooled estimates. Analyses were stratified by country and region.

Results: Approximately 80% of both younger and older adolescents reported ≥60 min of MVPA ≥1 days per week. This prevalence was ≥94% in Europe and Central Asia and North America, while the estimates for the other regions were <77%. The prevalence of ≥60 min of MVPA ≥1 days per week was higher among boys than girls, with the largest differences occurring among the oldest adolescents (Prevalence ratio_≤14y = 1.04 (95% confidence interval (95%CI)): 1.03‒1.04) vs. Prevalence ratio_>14y = 1.09 (95%CI: 1.08‒1.10)).

Conclusion: Approximately 8 out of 10 adolescents reported accumulating ≥60 min of MVPA ≥1 days per week, with notable differences between regions. Gender differences were observed in several countries, especially among the oldest adolescents. Priorities for physical activity promotion among adolescents should include increasing access/opportunities for physical activity among those who do not achieve ≥60 min of MVPA ≥1 days per week and reducing gender inequalities.

Background: Lifestyle plays an important role in preventing and managing gastroesophageal reflux disease (GERD). In response to the conflicting results in previous studies, we performed a systematic review and meta-analysis to investigate this association.

Methods: Relevant studies published until January 2023 were retrieved from 6 databases, and the prevalence of symptomatic gastroesophageal reflux (GER) or GERD was determined from the original studies. A random effects model was employed to meta-analyze the association by computing the pooled relative risk (RR) with 95% confidence intervals (95%CIs). Furthermore, subgroup and dose-response analyses were performed to explore subgroup differences and the association between cumulative physical activity (PA) time and GERD.

Results: This meta-analysis included 33 studies comprising 242,850 participants. A significant negative association was observed between PA and the prevalence of symptomatic GER (RR = 0.74, 95%CI: 0.66-0.83; p < 0.01) or GERD (RR = 0.80, 95%CI: 0.76-0.84; p < 0.01), suggesting that engaging in PA might confer a protective benefit against GERD. Subgroup analyses consistently indicated the presence of this association across nearly all subgroups, particularly among the older individuals (RR_{<40 years}:RR_{≥40 years} = 0.85:0.69, p < 0.01) and smokers (RR_smoker:RR_non-smoker = 0.67:0.82, p = 0.03). Furthermore, a dose-response analysis revealed that individuals who engaged in 150 min of PA per week had a 72.09% lower risk of developing GERD.

Conclusion: Maintaining high levels of PA decreased the risk of GERD, particularly among older adults and smokers. Meeting the recommended PA level of 150 min per week may significantly decrease the prevalence of GERD.