Impact of absent crowds on technical and physical performances in the Chinese Soccer Super League.

Purpose: Spectators have a significant impact on match performances in soccer, but to what extent crowd support contributes to the technical and physical performances remains unclear. This study aimed to (1) investigate the differences in terms of technical and physical performances with and without spectators; and (2) identify the key factors differentiating between win and loss when playing with and without the presence of an audience. Methods: Our study examined 794 performance records from 397 matches during the 2019-2020 seasons in the Chinese Soccer Super League. The least absolute shrinkage and selection operator (LASSO)-logistic regression was utilized to select significant predictors. Using an independent t-test and the Mann-Whitney non-parametric test explores the difference between matches with and without spectators. Key factors between win and loss were explored using univariate and multivariate logistic regression analyses. Results: Our study found that cross (p < 0.01, ES = -0.24), shots (p < 0.001, ES = -0.25), and shot accuracy (p < 0.05, ES = -0.18) displayed decreasing trends whereas sprint distances (p < 0.05, ES = 0.16) presented an increasing trend without spectators comparing with the crowd support. Moreover, the above three technical variables were the main factors differentiating between wins and losses. Similarly, team and opponent quality remained important potential factors affecting the match outcome. Conclusion: Match outcome or team performance is determined by a myriad of factors, but there are clear differences in technical and physical performances between matches with and without the presence of an audience. Similarly, our study provides a better explanation for the impact of crowd support on match performances whereby coaches can deploy players and adjust match strategies for ultimate success.

A warm-up performed with proper-weight sandbags on the leg improves the speed and RPE performance of 100 m sprint in collegiate male sprinters.

BACKGROUND: Muscle performance can be notably improved following a preloading maximal or near maximal stimulus due to the induction of postactivation potentiation, but the success of a preloading exercise in generating a postactivation potentiation response depends on the balance between fatigue and potentiation. However, the optimal warm-up strategy for sprint runners before a match may be not well established until now. METHODS: Fifteen well-trained male sprint runners performed four different warm-up protocols: warm-up with 0% body mass; warm-up with 2% body mass; warm-up with 4% body mass; warm-up with 8% body mass. The weight-bearing sandbag was tied about 3~5 cm above each ankle joint. During the 100-meter test, the time and rating of perceived exertion (RPE) in the first 30 meters, time in the first 60 meters, and time in the 100 meters were recorded, respectively. Two-high-speed digital video cameras were separately set in the sagittal planes on the left side of a line drawn at a distance of 30 m and 60 m from the start line to record the sprint motion. RESULTS: A warm-up performed with a sandbag weighted 4% of body mass could significantly improve the time and the RPE score of 100 m sprint by improving average velocity, stride frequency, average stride length, and average accelerated velocity during the sections of 0~30 m, 30~60 m and 60~100 m. This positive effect was better than that of 2% body-weigh effect. However, a warm-up performed with a sandbag weighted 8% of body mass had no significant influence on the performance of a 100 m sprint. CONCLUSIONS: Current results indicated that a warm-up performed with proper-weight(4% body mass) sandbags on the leg was beneficial to the improvement of 100 m sprint performance, and the mechanism might be that it effectively activated the main muscles and neuromuscular regulation of running and produced a better postactivation potentiation.

Endurance exercise protects aging Drosophila from high-salt diet (HSD)-induced climbing capacity decline and lifespan decrease by enhancing antioxidant capacity.

A high-salt diet (HSD) is a major cause of many chronic and age-related defects such as myocardial hypertrophy, locomotor impairment and mortality. Exercise training can efficiently prevent and treat many chronic and age-related diseases. However, it remains unclear whether endurance exercise can resist HSD-induced impairment of climbing capacity and longevity in aging individuals. In our study, flies were given exercise training and fed a HSD from 1-week old to 5-weeks old. Overexpression or knockdown of salt and dFOXO were built by UAS/Gal4 system. The results showed that a HSD, salt gene overexpression and dFOXO knockdown significantly reduced climbing endurance, climbing index, survival, dFOXO expression and SOD activity level, and increased malondialdehyde level in aging flies. Inversely, in a HSD aging flies, endurance exercise and dFOXO overexpression significantly increased their climbing ability, lifespan and antioxidant capacity, but they did not significantly change the salt gene expression. Overall, current results indicated that a HSD accelerated the age-related decline of climbing capacity and mortality via upregulating salt expression and inhibiting the dFOXO/SOD pathway. Increased dFOXO/SOD pathway activity played a key role in mediating endurance exercise resistance to the low salt tolerance-induced impairment of climbing capacity and longevity in aging DrosophilaThis article has an associated First Person interview with the first author of the paper.