Objective: The aim of this study was to develop and evaluate binary classification models to detect physical fatigue in badminton athletes using inertial measurement unit (IMU) data and machine learning algorithms. Methods: Thirty-two collegiate badminton athletes participated in this study. Movement data of these participants were collected using multi-sensor IMUs placed on key body regions and a single forearm IMU sensor before and after fatigue induction. Feature selection was performed using Lasso regression to identify the most relevant kinematic features. Six machine learning models—support vector machine (SVM), random forest (RF), logistic regression (LR), k-nearest neighbors (KNN), decision tree (DT), and naïve Bayes (NB)—were applied to construct binary classification models to detect fatigue. Models’ performances were evaluated based on area under the curve (AUC), accuracy, sensitivity, precision, and F1 score. Results: Overall performance of the SVM model was the best across both multi-sensor and single-sensor configurations, with AUC values of 0.89 and 0.95. The single-sensor forearm IMU model achieved high predictive accuracy, underscoring the feasibility of using simplified setups for fatigue monitoring. Feature selection by Lasso regression revealed key fatigue indicators, including forearm kinematic features, contributing significantly to model accuracy. Conclusion: IMU data combined with machine learning models can reliably be used to assess physical fatigue in badminton athletes. High performances of multi-sensor and single-sensor configurations suggest flexibility in model application, supporting real-time, field-based monitoring for fatigue management, performance optimization, and injury prevention in sports. Future research should validate these models in broader athletic populations and explore additional data sources to enhance their predictive abilities.

Purpose: To quantify the acute effects of a spectrum of eccentric load reductions on neuromechanical adjustments during the performance of weighted jump squats (WJSs). Methods: On separate days, 16 well-trained participants performed WJS trials with various eccentric load reductions (0% [body mass only], 25%, 50%, 75%, and 100% [standard WJS] of concentric load) with a mechanical braking unit, while concentric load was set at 30% of peak isometric squat force in all trials. A force platform and a motion-capture system were used to assess neuromuscular performance. Results: Peak power output was 6.2% (4.7%) higher when load was reduced by 50% versus 0% (55.4 [7.8] vs 51.9 [7.6] W/kg; P = .001). Compared with no braking (0.326 [0.059] m), jump height was ∼13% to 17% higher for all eccentric load reduction conditions (all P < .001). Vertical ground reaction forces were progressively lower for 25%, 50%, 75%, and 100% loading conditions (–22.1% [14.6%], –32.3% [10.8%], –42.0% [13.2%], and –46.1% [14.7%]; all P ≤ .001) in reference to body mass only. Conclusion: Eccentric load reduction is advantageous compared with traditional isoinertial loading for improving both jump height and peak power output during the concentric portion of maximal-effort WJS. This practice also decreases mechanical constraints in the lower extremities, which may become beneficial for load-compromised individuals.

Purpose: Confronted with the challenges of aging population, disease spectrum changes and non-communicable diseases (NCDs) burden, integrated health care(IHC) has become popular in recent decades. This paper aims to explore its global progress, current foci and future trends.

Objective: Insulin resistance (IR) is a complex and multifactorial disorder that contributes to type 2 diabetes and cardiovascular disease. MicroRNAs (miRNAs) play important roles in diverse developmental and disease processes. However, the molecular mechanisms of IR are unclear. This paper aims to explore the role of miRNA in regulating IR and to elucidate the mechanisms responsible for these effects. Methods: IR models were created by feeding a high-fat diet (HFD) to mice or stimulating 3T3-L1 cells with palmitate. Twelve weeks of HFD trigger weight gain, leading to lipid accumulation and insulin resistance in mice. The expression profiles of miRNAs in adipose tissues (AT) from the HFD-induced mouse models were analyzed. The relationship between miR-221-3p and SOCS1 was determined using dual luciferase reporter gene assays. Metabolic alterations in AT were investigated by real-time PCR and Western blot. Results: miR-221-3p was significantly increased in AT. HFD-induced disturbances in glucose homeostasis were aggravated by miR-221-3p upregulation. The inhibition of miR-221-3p promoted insulin sensitivity including reduced lipid accumulation and the disruption of glucose metabolism. Of note, the 3′-UTR of SOCS1 was found to be a direct target of miR-221-3p. The SOCS1 inhibitor attenuated miR-221-3p-induced increases in IRS-1 phosphorylation, AKT phosphorylation, and GLUT4. miR-221-3p was considered to be involved in the PI3K/AKT signaling pathway, thus leading to increased insulin sensitivity and decreased IR in HFD-fed mice and 3T3-L1 adipocytes. Conclusions: The miR-221-3p/SOCS1 axis in AT plays a pivotal role in the regulation of glucose metabolism, providing a novel target for treating IR and diabetes.

This study aimed to evaluate the effects of three different crank lengths (165 mm, 170 mm, and 175 mm) on cycling efficiency, sprint performance, and perceived fatigue in high-level amateur road cyclists. A single-blind, randomized crossover design was employed, involving 28 trained male cyclists who completed three trials, each using a different crank length. Performance metrics, cycling economy (CE) including 20-min cycling under 60 % VO_2MAX, peak and average power during a 6s sprint, cadence, heart rate, and perceived exertion, were measured using validated ergometers and metabolic analyzers. The results indicated significant differences in 60 %VO_2MAXRPE were observed between the 165 mm and 175 mm cranks (p < 0.001, δ = -0.72) and between the 175 mm and 170 mm cranks (p < 0.001, δ = -0.67). In contrast, no significant difference was observed between the 165 mm and 170 mm cranks (p = 0.25, δ = -0.17). For 60 %VO_2MAX, 6sMaxPower, 6sAVPower, 6sAVRpm, CE, 60 %VO_2MAXAVHeart, 6sMaxRpm no significant differences were observed between any of the crank length groups (p > 0.34). For high-level amateur road cyclists, using a 165 mm or 170 mm crank reduces subjective fatigue compared to a 175 mm crank, influencing affecting cycling efficiency or sprint performance. These findings help refine crank length recommendations to optimize performance, reduce injury risk, and improve comfort for high-level amateur road cyclists.

Purpose: To compare the effects of 6-week barbell weighted-jump-squat (WJS) training with and without eccentric load reduction on explosive performance. Methods: Twenty well-trained male athletes were randomly assigned to either an experimental group (n = 10) or a control group (n = 10). Participants completed 12 WJS training sessions (6 sets of 5 repetitions of barbell back squat at 30% of 1-repetition maximum [1RM]) twice a week over a 6-week period. While the control group used 0% eccentric loading (ie, traditional WJS), the experimental group utilized a 50% eccentric loading reduction with a mechanical braking unit (ie, eccentric load set at 15% of 1RM). Performance assessments, including countermovement jump, 20-m sprint, standing long jump, and 1RM barbell back squat, were conducted both before (pretests) and after (posttests) the intervention. Results: Both the experimental group and the control group demonstrated a significant increase in countermovement-jump height (+6.4% [4.0%] vs +4.9% [5.7%]; P < .001) and peak power output (+2.3% [2.7%] vs +1.9% [5.1%]; P = .017), faster 20-m sprint times (+9.4% [4.8%] vs +9.2% [5.5%]; P < .001), longer standing long jump (+3.1% [2.5%] vs +3.0% [3.3%]; P < .001), and higher 1RM back squat (+6.4% [4.0%] vs +4.9% [5.7%]; P < .001) from pretests to posttests. However, there was no significant condition × time interaction for any variable (all P ≥ .294). Conclusions: Both WJS training methods, with and without load reduction in the eccentric phase, effectively enhance explosive performance. Nevertheless, athletes in later stages of injury rehabilitation or intense training may find reducing eccentric load a more tolerable strategy for achieving similar performance gains compared with traditional isoinertial loading.