This systematic review and meta-analysis aims to investigate the effects and differences of various hamstring eccentric training protocols for the prevention of lower limb injuries, and we further propose a more refined hamstring eccentric training protocol for the prevention of lower limb injuries. A literature search for the effects of hamstring eccentric training on lower extremity sports injuries was conducted using the PubMed, Web of Science, and EMBASE databases, and the literature was searched covering the period from the date of the database’s creation to 20 August 2022. A meta-analysis of the included literature was performed using R.4.21 for lower extremity injuries, injuries in various parts of the lower extremity, and subgroup analysis for exercise frequency, exercise cycle, and exercise population. A total of 23 randomized controlled trial (RCT) studies were found to be included in the meta-analysis, and 15 of these trials, totaling 14,721 patients, were determined to be included in the overall lower extremity injury prevention effect. The analysis showed that the implementation of a hamstring eccentric training program reduced lower extremity injuries by 28%, and it resulted in a 46% decrease in hamstring injury rate and a 34% decrease in knee injury rate. The subgroup analysis revealed that the frequency of exercise was most significant in the twice-a-week exercise group, that the exercise program was most effective in preventing injuries in the 21–30-week exercise period, and that the program was most effective in preventing injuries in elite athletes and amateur adult athletic populations, compared with adolescents.

Post-activation performance enhancement (PAPE) can significantly improve athletic performance. This study investigated the effects of two different velocity loss (10% VL and 20% VL) protocols on PAPE in 20 m sprint performance among sprint athletes. Twenty-four male sprint athletes (100 m sprint time: 10.96 ± 0.15 s) participated in the study. A randomized crossover experimental design was used to compare the traditional group (TG) and 10% VL and 20% VL interventions. Sprint tests were conducted at 4, 8, 12, and 16 min post-intervention. A two-way repeated measures ANOVA revealed a significant interaction effect between group and time on 20 m sprint performance (F = 2.817, p = 0.037, partial η² = 0.585). Simple main effects analysis revealed significant improvements at 4 min for the 20% VL group (p < 0.05). Cohen’s d values indicated improvements in 10 m sprint times at 8 min for all groups (TG: effect size (ES) = −0.270, 10% VL: ES = −0.038, 20% VL: ES = −0.279). Improvements in 20 m sprint times were observed at 4 min for the 20% VL group (ES = −0.296) and at 16 min for the 10% VL group (ES = −0.276). In conclusion, the velocity loss-based PAPE protocol (20% VL) demonstrated a superior induction of PAPE effects in sprint athletes at 4 min compared to traditional 1RM-based PAPE protocols. However, no significant differences were observed between the two protocols at 8, 12, and 16 min.

The aging process leads to the degeneration of body structure and function. The objective of this study is to conduct a systematic review and meta-analysis of the effects of resistance circuit training (RCT) on comprehensive health indicators of older adults. PubMed, Embase, and Web of Science were searched until August 2023. Primary outcomes were body composition, muscle strength, cardiorespiratory endurance, blood pressure, and functional autonomy. Muscle function and exercise intensity subgroups were analyzed. RCT reduces body fat (MD = − 5.39 kg, 95% CI − 10.48 to − 0.29), BMI (MD = − 1.22, 95% CI − 2.17 to − 0.26), and body weight (MD = − 1.28 kg, 95% CI − 1.78 to − 0.78), and increases lean body mass (MD = 1.42 kg, 95% CI 0.83–2.01) in older adults. It improves upper limb strength (SMD = 2.09, 95% CI 1.7–2.48), lower limb strength (SMD = 2.03, 95% CI 1.56–2.51), cardiorespiratory endurance (MD = 94 m, 95% CI 25.69–162.67), and functional autonomy (MD = − 1.35, 95% CI − 1.73 to − 0.96). High-intensity RCT benefits BMI and body weight, while low-intensity exercise reduces blood pressure. RCT improves muscle function in push, pull, hip, and knee movements in older adults. RCT improves body composition, muscle strength, cardiorespiratory endurance, blood pressure, and functional autonomy in older adults. High-intensity training is superior for body composition, while moderate to low intensity training is more effective for lowering blood pressure.

Objectives: The aim of this study was to assess the relationship between variant loci significantly associated with sports-related traits in the GWAS Catalog database and sprint/power athlete status, as well as to explore the polygenic profile of elite athletes. Methods: Next-generation sequencing and microarray technology were used to genotype samples from 211 elite athletes who had achieved success in national or international competitions in power-based sports and from 522 non-athletes, who were healthy university students with no history of professional sports training. Variant loci collected from databases were extracted after imputation. Subsequently, 80% of the samples were randomly selected as the training set, and the remaining 20% as the validation set. Results: Association analysis of variant loci was conducted in the training set, and individual Total Genotype Score (TGS) were calculated using genotype dosage and lnOR, followed by the establishment of a logistic model, with predictive performance evaluated in the validation set. Association analysis was performed on 2075 variant loci, and after removing linked loci (r² > 0.2), 118 Tag SNPs (p ≤ 0.05) were identified. A logistic model built using 30 Tag SNPs (p ≤ 0.01) showed better performance in the validation set (AUC = 0.707). Conclusions: Our study identified 30 new genetic molecular markers and demonstrated that elite sprint/power athlete status is polygenic.

This study explored the effects of partial sleep deprivation (PSD) on Sanda athletes' athletic performance, an area with limited research. Using a randomized crossover controlled trial with 18 male athletes, the PSD group had 4 h of sleep while the NSN group had 8 h. Results showed that after PSD intervention, the RAT time significantly increased compared to the NSN group (P = 0.0311). However, there was no significant change in CMJ (P = 0.2396) or YBT (left leg: P = 0.2767, right leg: P = 0.3225) between the PSD and NSN groups. In the Wingate test, the PSD group exhibited significant reductions in Pmax and Pave at 10s, 30s, and 60s (P＜0.0001), as well as a significant decrease in Prel at 60s (P＜0.0001), with no significant differences in Prel at 10s and 30s. These findings underscore the detrimental impact of limited sleep on anaerobic performance and agility in Sanda athletes, emphasizing the need for proper sleep management for optimal athletic outcomes.

To explore neuromuscular control during blood flow restriction (BFR) squat exercise using wavelet packet transform (WPT) combined with non-negative matrix factorization (NMF). Fifteen resistance-trained males completed four sets of squats at 40% arterial occlusion pressure. Countermovement jump (CMJ) height and reactive strength index modified (RSImod) alongside surface electromyographic activity from eight lower-limb muscles were assessed before after the exercise. CMJ height and RSImod significantly increased post-exercise (P < 0.001, Cohen's d = 0.45 and 0.34, respectively). Four muscle synergy modules were consistently identified, though primary muscle contributions shifted across movement phases. The tibialis anterior (TA) was the primary contributor in Synergy1, while the gastrocnemius lateralis (GL) dominated Synergy 2, accompanied by a significant increase in gluteus maximus (GM) weight (P = 0.032). In Synergy 3, the rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM) were predominant, with significant changes in GM and VM muscle weights (P = 0.013, 0.039). Synergy 4 was characterized by contributions from the semitendinosus (ST), biceps femoris (BF), and GM, with a significant increase in VL muscle weight (P = 0.024). WPT-NMF analysis revealed distinct time-frequency synergy modules in CMJ movements before and after BFR squat exercise. Significant changes in activation weights were observed within the 0-250 Hz range (P < 0.05). BFR squat exercise acutely enhances countermovement jump performance by refining muscle synergy and neuromuscular activation patterns, providing novel insights into neuromuscular control strategies.