Effects of pitch spatial references on players’ positioning and physical performances during football small-sided games     

Diogo Coutinho  Bruno Gonçalves  Bruno Travassos  Eduardo Abade  Del P. Wong  Jaime Sampaio 《Journal of sports sciences》2019,37(7):741-747

The aim of this study was to identify the effects of adding spatial references during football small-sided games in youth players’ tactical and physical performance. Twelve under-15 players performed a Gk+ 6v6+ Gk game under two playing conditions: (i) without spatial references (CONTROL condition); (ii) with spatial references, by dividing equally the pitch into three corridors and three sectors (experimental situation, LINES). Players’ positional data was used to compute time-motion and tactical-related variables. The results revealed that performance under LINES situation increased the regularity in the zones occupied (~14%, Cohen’s d: 0.5; ±0.3; p = 0.003) and in the distance between teammates’ dyads (~19%, 0.9; ±0.2; p < 0.001). Oppositely, LINES condition decreased the longitudinal synchronization of players’ displacements (0.4; ±0.2; p = 0.002), players’ average speed (0.5; ±0.3; p = 0.002) and distance covered at lower (0.9; ±0.3; p < 0.001) and moderate speed (0.5; ±0.3; p < 0.001). Adding spatial references seems to promote a more structured pattern of play and increase positional regularity. However, coaches should be aware that this constraint may decrease the synchronization between players. Overall, these findings may be generalized to most invasion team sports.  相似文献   

Heart rate recovery after aerobic and anaerobic tests: is there an influence of anaerobic speed reserve?     

Sebastián Del Rosso  Fabio Y. Nakamura 《Journal of sports sciences》2017,35(9):820-827

The present study assessed if differences in the metabolic profile, inferred from the anaerobic speed reserve (ASR), would influence the dynamics of heart rate recovery (HRR) after two modes of exercise. Thirty-nine physical education students (14 females and 25 males) volunteered for this study. Participants carried out three separate testing sessions to assess maximal sprinting speed (MSS, 1st session), repeated sprint ability (RSA, 2nd session) and maximal aerobic speed (MAS) using the Université of Montreal Track Test (UMTT, 3rd session). ASR was defined as the difference between MSS and MAS. Heart rate was continuously registered throughout the tests and during the 5-min post-test recovery. To evaluate the influence of ASR on post-exercise, HRR comparisons between ASR-based groups [high ASR vs. low ASR] and sex groups (males vs. females) were performed. Significant differences (P < 0.05) were found between high ASR and low ASR groups of the same sex for indices of relative HRR after the RSA and UMTT. In addition, after the RSA test, males from the high ASR group had a significantly slower HRR kinetics compared with the males of the low ASR (P < 0.05) and the females of high ASR (P < 0.05); whereas females of the high ASR groups had a faster HRR kinetics compared with the females of low ASR group (P < 0.05). Our results showed that in males, post-exercise HRR could be related to the ASR, whereas in females, the influence of ASR is less clear.  相似文献   

Analysis of doping control test results in individual and team sports from 2003 to 2015     

Millan Aguilar-Navarro  Jesus Munoz-Guerra  Maria del Mar Plara  Juan Del Cosoa 《运动与健康科学(英文)》2020,9(2):160-169

Background:Determining the prevalence of doping in sport might be useful for anti-doping authorities to gauge the effectiveness of anti-doping policies implemented to prevent positive attitudes toward doping.Using questionnaires and personal interviews,previous investigations have found that the prevalence of doping might be different among different sports disciplines;however,there is no sport-specific information about the proportion of adverse and atypical findings(AAF) in samples used for doping control.The aim of the present investigation was to assess the differences in the frequency of adverse analytical and atypical findings among sports using the data made available by the World Anti-Doping Agency.Methods:The data included in this investigation were gathered from the Testing Figures Reports made available annually from 2003 to 2015 by the World Anti-Doping Agency.These Testing Figures Reports include information about the number of samples analyzed,the number of AAFs reported,and the most commonly found drugs in the urine and blood samples analyzed.A total of 1,347,213 samples were analyzed from the individual sports selected for this investigation,and 698,371 samples were analyzed for disciplines catalogued as team sports.Results:In individual sports,the highest proportions of AAF were 3.3%±1.0% in cycling,3.0%±0.6% in weightlifting,and 2.9%±0.6% in boxing.In team sports,the highest proportions of AAF were 2.2%±0.5% in ice hockey,2.0%±0.5% in rugby,and 2.0%±0.5% in basketball.Gymnastics and skating had the lowest proportions at(≤1.0%) for individual sports,and field hockey,volleyball and football had the lowest proportions for team sports(≤1.4%).Conclusion:As suggested by the analysis,the incidence of AAF was not uniform across all sports disciplines,with the different proportions pointing to an uneven use of banned substances depending on the sport.This information might be useful for increasing the strength and efficacy of anti-doping policies in those sports with the highest prevalence in the use of banned substances.  相似文献