Background: Branched-chain amino acids (BCAAs, isoleucine, leucine, and valine) are commonly applied to promote muscle protein synthesis. However, the effects of BCAAs on exercise-induced substrate metabolism, performance and post-exercise fatigue during endurance exercise remain unclear. Methods: In a double-blind cross-over design, eleven active males completed 1 h of constant load exercise (CLE) at 60% VO₂max power followed by a time to exhaustion (TTE) test at 80% VO₂max power after supplementation with BCAAs or placebo on consecutive three days. During exercise, indirect calorimetry was used to measure the carbohydrate (CHO) and fat oxidation rate, as well as the cycling efficiency. In addition, rating of perceived exertion (RPE) and visual analogue scale (VAS) scores were obtained at interval times during the whole period. Fingertips and venous blood (n = 8) were collected for the measurement of metabolic responses at different time points during exercise. Results: Compared to the placebo group, the fat oxidation rate was significantly higher after 20 and 30 min of CLE (p < 0.05). The CHO oxidation rates showed a significant increase in the BCAA group during TTE (p < 0.05). Meanwhile, the cycling efficiency during TTE was significantly improved (p < 0.05). Interestingly, VAS significantly decreased post-exercise in the BCAA group (p < 0.05). Additionally, the levels of blood insulin between the two groups were significantly higher in the post-exercise period compared to the pre-exercise periods (p < 0.001), while insulin levels were significantly lower in the post-exercise period with supplemental BCAAs compared to the placebo (p < 0.001). BCAAs also enhanced the levels of blood ammonia in the post-exercise period compared to the fasting and pre-exercise periods (BCAA: p < 0.01; Placebo: p < 0.001). However, in the post-exercise period, blood ammonia levels were significantly lower in the BCAA group than in the placebo group (p < 0.05). Conclusions: This study shows the critical role of BCAAs during exercise in active males and finds that BCAA supplementation enhanced fat oxidation during the CLE, increased carbohydrate oxidation and exercise efficiency during the TTE, and reduced immediate post-exercise fatigue.

A Chinese Compilation of Physical Activities was compiled to estimate the energy costs of physical activities (PAs) using data on adults aged 18–64. Data were obtained from published articles and laboratory measurements. Databases, including PubMed, Embase, Scopus, Ebsco, Web of Science, Chinese National Knowledge Infrastructure, Wan Fang Data, National Science and Technology Report Service, Public Health Scientific Data were searched to collect data from inception to January 2022, on energy expenditure associated with PA in the healthy Chinese population. Two reviewers independently screened the literature and extracted, classified, and summarized data. Data were measured for 36 PAs using indirect calorimetry. Detailed descriptions of specific activities and metabolic equivalent values were provided by summarizing 241 physical activities in 13 categories. The first edition of the Chinese Compilation of PAs in Healthy Adults Aged 18–64(CCPA) was created. It provides valuable resources for people who regularly engage in physical exercise, researchers, educators, fitness professionals, and health or commercial sectors to quickly obtain various PA MET intensities. In the future, the energy expenditure of various PAs of different ages within the Chinese population can be measured based on the CCPA.

Introduction: To explore and develop a backpropagation neural network-based model for predicting and generating exercise prescriptions for improving cardiorespiratory fitness in older adults.Methods: The model is based on data from 68 screened studies. In addition, the model was validated with 64 older adults aged 60–79 years. The root mean square error (RMSE), mean absolute error (MAE) and coefficient of determination (R²) were used to evaluate the fitting and prediction effects of the model, and the hit rate was used to evaluate the prediction accuracy of the model.Results: The results showed that (1) The mean error ratios for predicting exercise intensity, time and period were 7% ± 12, −5% ± 9% and − 7% ± 14%, respectively, indicating that the estimates were in good agreement with the expected results. (2) Of the 61 subjects who completed the assigned program, cardiorespiratory fitness improved significantly compared with pre-exercise. Improvements ranged from 9.2–10% and 8.9–15.8% for female and male subjects. (3) In addition, 71 and 94% of subjects (43/61) showed cardiorespiratory improvement within plus or minus one standard deviation and plus or minus 1.96 times standard deviation.Discussion: A neural network-based model for exercise prescription for cardiorespiratory fitness improvement in older adults is feasible and effective.

Physical inactivity plays a role in the incidence of cardiovascular disease (CVD). Although the current guidelines for physical activity, such as the prescription of exercise, seek to combat CVD, attaining the recommended targets remains challenging. Tennis exercise has been proven to have a unique advantage in reducing the mortality of CVD, but little is known about the influence of playing tennis on impaired vascular endothelial function (VEF), which initiates CVD. Thus, this study aimed to investigate whether regular tennis participation could protect the VEF better than merely meeting the physical activity recommended by the current guidelines. A cross-sectional design was performed based on a sample of 38 healthy postmenopausal women who were matched for physical activity, of which 17 subjects had long-term tennis experience and 21 age-matched subjects regularly exercised but did not play tennis. The cardiovascular function and the body composition of all subjects were measured. We used cluster analysis to assess the overall health status. The modeling results showed that the tennis players performed better in terms of VEF than the nonplayers (10.55 ± 0.58 vs. 8.69 ± 0.52, p < 0.01, R²_ad = 0.367), while the wall shear stress positively correlated with VEF (r = 0.505, p < 0.05), after controlling for age and physical activity levels. Regular tennis exercise may be a protective factor for VEF, and further study should be performed to research the role of hemodynamics in tennis exercise.

Brown adipose tissue (BAT) is a critical target for obesity treatment, and exercise can enhance BAT function through the activation of ADRβ3. However, the molecular mechanisms underlying BAT metabolism following the exercise-induced activation of ADRβ3 remain unclear. This study utilized RNA sequencing, Western blotting, Oil Red O staining, weighted gene co-expression network analysis (WGCNA), and machine learning to investigate the role of the ADRβ3-COX2 pathway in lipid metabolism in brown adipocytes. We identified Ywhah as a key gene and validated our findings using external datasets. Our results demonstrate that exercise significantly enhances brown adipose tissue metabolism in mice, with ADRβ3 activation promoting metabolic activity in brown adipocytes. In contrast, COX2 inhibition notably reduced the lipolytic effect and thermogenic gene expression induced by ADRβ3 activation. WGCNA and machine learning identified Ywhah as the most important feature variable in the downstream signaling of the ADRβ3-COX2 pathway. External microarray data further confirmed that 8 weeks of aerobic exercise significantly upregulated Ywhah expression. Additionally, Ywhah displayed strong binding affinity to cytoskeletal proteins in affinity purification–mass spectrometry experiments, and its expression was highly correlated with cytoskeletal GSVA scores. In summary, this study reveals the potential role of the ADRβ3-COX2-Ywhah-cytoskeleton axis in regulating brown adipocyte metabolism, providing new insights into obesity treatment mechanisms.

Background: Branched-chain amino acids (BCAAs) are popular as sports supplements due to their ability to enhance performance and recovery. However, the full spectrum of metabolic alterations triggered by acute supplementation with BCAAs in conjunction with exercise remains incompletely understood. Methods: A randomized crossover trial was conducted in 8 healthy active young males, who received either BCAA or placebo supplementation for three consecutive days prior to a high-intensity cycling test. Plasma samples were collected pre- and post-exercise and analyzed by ultra-high-performance liquid chromatography–quadrupole time-of-flight mass spectrometry, followed by correlation and enrichment analyses. Results: Acute BCAA supplementation was significantly associated with enhanced fat oxidation and attenuated post-exercise increases in plasma ammonia, creatine kinase, and lactate dehydrogenase, suggesting the potential improvements in energy supply and membrane stability. Metabolomics analysis identified differential metabolites primarily involved in lipid, amino acid, and glucose metabolism. Pathway enrichment revealed coordinated regulation of fatty acid oxidation (FAO) and tryptophan-related pathways. Correlation analysis further showed that changes in metabolite profiles were strongly associated with biochemical outcomes, particularly linking enhanced fat oxidation and ammonia clearance with BCAA intake. Conclusions: Short-term BCAA supplementation could enhance FAO and membrane stability via coordinated regulation of lipid and amino acid metabolism post exercise, supporting its potential role as a precision nutrition strategy.