International journal of sports medicine最新文献

This study aimed to investigate the effect of aerobic exercise under hypoxic conditions (FiO₂: 14.9%) on post-exercise hypotension compared to normoxic exercise matched for mechanical and physiological intensities. Twenty sedentary men completed three exercise sessions using a crossover design: (1) hypoxic exercise at 50% of peak power output, (2) normoxic exercise at 50% of peak power output (normoxic exercise matched for mechanical intensity), and (3) normoxic exercise with heart rates matched for hypoxic exercise. Expired gases and peripheral and muscle oxygen saturation were measured during the exercise. Blood pressure and hemodynamic variables were assessed before and after each exercise session. Hypoxic exercise and normoxic exercise matched for physiological intensity elicited higher heart rate, oxygen consumption, and ventilation compared to normoxic exercise matched for mechanical intensity (p<0.05). Hypoxic exercise showed the lowest ventilation efficiency (p<0.01) and the most severe systemic and muscle hypoxemia (p<0.01) during exercise. Only hypoxic exercise induced significant post-exercise hypotension (-6.9 mmHg; p<0.01) with a significant increase in common femoral artery diameter during recovery (p<0.05). Our findings suggested that hypoxic exercise significantly enhances post-exercise vasodilation compared to normoxic exercise, resulting in greater post-exercise hypotension. This highlighted hypoxic exercise as a promising strategy for managing hypertension with reduced mechanical stress, particularly beneficial for individuals with low exercise tolerance.

There is no doubt that sarcopenia is one of the most defining characteristics of aging that negatively impacts the people's health and quality of life. The condition is characterized by the progressive and generalized loss of muscle mass and strength, affecting physical performance. It is part of aging but can be exacerbated by pathophysiological conditions like cancer and several factors such as a sedentary lifestyle, poor nutrition, chronic diseases, falls and immobilization. Numerous cellular mechanisms have been implicated in its pathogenesis, including hormonal changes, mitochondrial dysfunctions, altered apoptotic and autophagic signaling, muscle fiber composition, and inflammatory pathways. To prevent sarcopenia, exercise is one of the most effective strategies as it has a strong influence on both anabolic and catabolic muscle pathways and helps improve skeletal muscle function. A well-rounded, multicomponent exercise program that targets muscle strength, aerobic capacity, and balance is recommended for optimal results. While nutrition is essential for muscle maintenance, relying solely on dietary interventions is unlikely to fully address sarcopenia. Therefore, a combination of adequate nutrition and regular exercise is recommended to promote muscle health and function. The purpose of this study is to review sarcopenia from an aging viewpoint and discuss the role of exercise and nutrition as prevention and management options.

We conducted a systematic review and meta-analysis of the effect of exercise training on common lipid subunits. We systematically searched PubMed, Web of Science and the Cochrane Library of Controlled Trials for randomized, controlled trials of exercise training versus sedentary controls that reported lipid subunits including apolipoprotein-AI, apolipoprotein-AII, apolipoprotein-B, high density cholesterol-2, high density cholesterol-3 and lipoprotein (a) up until January 31, 2024. Our search identified 2,363 potential studies. We included 25 studies with 34 intervention groups, and a total of 1,429 participants, 775 exercise training and 654 control. We found significant favourable anti-atherogenic changes in apolipoprotein-AI with a mean difference of 8.17 mg/dL and a 95% confidence interval of 5.80-10.55, lipoprotein (a) with a mean difference of -2.52 mg/dL and a 95% confidence interval of -4.33 to -0.72), apolipoprotein-B with a mean difference of -0.11 mg/dL and a 95% confidence interval 0f -0.19 to -0.04, and high density cholesterol-2 with a mean difference of 1.28 mg/dL and a 95% CI of 0.28-2.28. Our trial sequence analysis showed that futility was achieved for apolipoprotein-AI, but not for lipoprotein (a), apolipoprotein-B and high density cholesterol-2. The minimal clinically important differences for apolipoprotein-AI, lipoprotein (a), apolipoprotein-B and high density cholesterol-2 were 0.76, 0.46, 0.02 and 0.26 mg/dL, respectively. Analyses of apolipoprotein-AII and high density cholesterol-3 were not significant and these trial sequence analyses failed to show futility. Exercise training produces significant improvements in apolipoprotein-AI, lipoprotein (a), apolipoprotein-B and high density cholesterol-2, with the minimal clinically important differences being achieved. The effect of exercise training on apolipoprotein-AII and high density cholesterol-3 is unclear.

Females may experience less neuromuscular fatigue and improved recovery following resistance training than males; however, it is unclear whether this applies to resistance-trained individuals. A systematic scoping review was performed to map the evidence on sex differences in fatigue during and following resistance training in trained participants. PubMed, CINAHL and SPORTDiscus were searched following PRISMA-ScR guidelines. The protocol was prospectively registered. Of the 4,020 identified articles, 34 were included. These studies assessed sex differences in fatigue using various measures during single and multiple resistance training sets, performance relative to the baseline at various time points (0-5 min, 1-6 h, 24 h, and 48-96 h after resistance training), and metabolic responses. Substantial heterogeneity in study design and results were observed. Together, most studies found minor-to-no sex differences in neuromuscular fatigue, but some evidence of greater fatigability in males during or immediately following resistance training were found when (1) more complex free-weight exercises were performed with moderate loads, (2) rest periods were shorter, and (3) males were substantially stronger than females in relative terms, among others. Future investigations should explore the impact of training variables and habitual training on fatigue in males and females of comparable relative strength and technical proficiency.

The phase angle measured by bioelectrical impedance analysis is a potential indicator of exercise performance. Owing to the lack of studies on adolescent female athletes, this study aimed to investigate the relationship between whole-body and regional phase angles and exercise performance in adolescent female basketball players. Forty-five female basketball players (aged 16.6±0.6 y) participated in this study. Lean soft tissue and phase angles for the whole-body, upper limb, and lower limb were assessed using the bioelectrical impedance analysis method. Participants performed maximal isometric knee extension and flexion strength, 20-m sprint, a vertical jump, an agility T-test, and a 20-m shuttle run test. The phase angle for the whole-body and the phase angle for the upper limb, but not the phase angle for the lower limb, were significantly correlated with the 20-m sprint and endurance capacity (all p<0.01). Even after adjusting for age and lean soft tissue in multiple regression analysis, the phase angle for the whole-body and the phase angle for the upper limb remained a significant predictor of these parameters (all p<0.05). The phase angle for the upper limb, combined with age and lean soft tissue, explained endurance capacity similarly to the phase angle for the whole-body (adjusted R ²: 0.24 vs. 0.23) but was better for the 20-m sprint (adjusted R ²: 0.26 vs. 0.11). Both whole-body and regional phase angles are associated with sprint and aerobic performance in adolescent female basketball players. However, the regional phase angle can be an equivalent or superior predictor of these performance parameters compared with the whole-body phase angle.

This study aims to explore the relationship between blood biochemical indexes and injury risk for elite male athletes in racing ice sports. The study compared the demographic indexes, monthly injuries, and longitudinal tracking data for the athletes. The non-linear relationship was analyzed using an unrestricted cubic spline. Generalized estimating equations were used to estimate the relative risk (OR) of injury occurrence. Receiver operating characteristics and the area under the curve determined diagnostic accuracy. In the snow sledding group, when creatine kinase rises to 489.46 u/L or testosterone decreases to 41.32 ng/ml, the risk increases by 1.70 times (OR=1.70, p<0.001) and 1.69 times (OR=1.69, p<0.001) with statistical significance. The creatine kinase (OR=1.01, P=0.007) and testosterone (OR=1.00, P<0.001) were included in the injury prediction model. The model exhibits excellent discrimination, with sensitivity and specificity of 82.8% and 86.5%, respectively. In the ice skating group, when creatine kinase rises to 467.00 u/L, the risk increases by 2.56 times with statistical significance (OR=2.56, p<0.001). Creatine kinase (OR=1.01, P<0.001) was included in the predictive model. The model demonstrates good discrimination, with sensitivity and specificity of 90.5% and 66.7%, respectively. Creatine kinase and testosterone are the risk predictors of injury in elite snowmobile male athletes. Creatine kinase is an independent risk factor for injury in elite speed skaters.

The effects of estradiol and progesterone fluctuations during the menstrual cycle (MC) on strength and fatigue remain unclear. This study investigated their impact on peak torque and fatigue in isokinetic tests. Eleven strength-trained women performed five knee extensions and flexions to assess maximum peak torque, rating of perceived exertion (RPE), and rating of perceived pain (RPP). A separate protocol of 60 repetitions was used to evaluate peak torque, total work, percentage of work fatigue, RPE, RPP, and blood lactate concentration before and after exercise. MC phases were determined using a combination of calendar tracking, urinary ovulation tests, and serum hormone analysis. A one-way repeated-measures analysis of variance, followed by Bonferroni's post hoc tests and effect size calculations (partial eta-square), analyzed differences across six MC phases. No significant differences were observed in peak torque, RPE, or RPP during knee extension and flexion (p>0.05). Similarly, fatigue parameters assessed during the 60-repetition test showed no significant variation across MC phases (p>0.05). However, blood lactate concentrations were significantly higher postexercise than preexercise (p<0.05). These findings suggest that strength performance and muscle fatigue are not influenced by hormonal fluctuations across the MC in strength-trained women.

Osteoarthritis (OA) is a common, multi-factorial and -aetiological condition, causing pain, disability and reduced function. Post-traumatic OA (PTOA) is more common in younger populations, especially after anterior cruciate ligament (ACL) or meniscal injury. Identifying those at increased risk of PTOA using molecular, imaging and biomechanical biomarkers is a research priority. This systematic review aims to identify functional tasks used to assess knee kinematics and kinetics at least a year from injury, describe any differences found between the injured and uninjured contralateral and control knees and identify associations with PTOA. Searches were performed on Medline, CINAHL and EMBASE, with reference lists reviewed. The initial search yielded 2504 studies, with six more detected from reference lists. Thirty-three studies involving 1251 participants (n=737 injured, all ACL, mean age 25.1, 49.9% male, 1-13 yr post-injury) were included. Studies included the following dynamic tasks: landing (n=25), jumping (n=3), cutting (n=5) or squatting (n=3). Overall, reductions in knee flexion and extension angles and moments, increased knee valgus and energy absorption were demonstrated in injured knees. However, this was inconsistent across studies, with data heterogeneity preventing direct comparison and meta-analysis. Changes in biomechanics are present from 1-year post-injury, persisting for several years; however, consensus regarding core outcome sets is required.