Acute Effects of Active, Ballistic, Passive, and Proprioceptive Neuromuscular Facilitation Stretching on Sprint and Vertical Jump Performance in Trained Young Soccer Players.

Oliveira, LP, Vieira, LHP, Aquino, R, Manechini, JPV, Santiago, PRP, and Puggina, EF. Acute effects of active, ballistic, passive, and proprioceptive neuromuscular facilitation stretching on sprint and vertical jump performance in trained young soccer players. J Strength Cond Res 32(8): 2199-2208, 2018-The aim of this study was to compare the acute effects of active (AC), ballistic (BA), passive (PA), and proprioceptive neuromuscular facilitation (PNF) stretching methods on performance in vertical jumping, sit and reach, and sprinting in young soccer players. Twelve trained soccer players (17.67 ± 0.87 years) participated in the study. The jump height (H), peak power (PP), and relative power (RP) in the squat jump (SJ) and countermovement jump (CMJ), the range of motion (ROM), the rating of perceived exertion (RPE), and time (seconds) in 10-20-30-m sprints were evaluated. Significant differences (p < 0.05) in H were found in the comparisons between the PA and control (CO) condition for the SJ. For the CMJ, differences in H were observed between the PA and CO, and PNF with CO and BA, and in the PP between the PNF and CO, AC, and BA, as well as in the RP between the PNF and BA. Significant increases in ROM were found in the AC, BA, PA, and PNF compared with the CO. In relation to RPE, higher scores were reported in the PA and PNF conditions compared with the AC and BA. No significant differences were found in 10-20-30-m sprints. Therefore, the AC and BA methods can be used before vertical jump and sprint activities, with the aim of increasing flexibility. However, the PA and PNF methods should be avoided because of subsequent negative effects on vertical jump performance.

Effects of match situational variables on possession: the case of England Premier League season 2015/16

Aim: The main aim of this study was to identify the effects of match location, quality of opponents and match status on possession during the 2015/16 Season of England Premier League. Methods: Three hundred and eighty matches played by 20 teams were analysed. For each match, two values were recorded, resulting in 760 observations. Results Teams who played at home (51.77 ± 10.22%) presented higher possession values (EF=moderate) than those who played away (48.21 ± 10.30%). Quality of opponents also had a significant difference, as possession was higher (EF=large) when teams played against weak (52.30 ± 9.77%) than strong opponents (46.48 ± 10.38%). The multivariate analysis revealed no interaction between situational variables and possession (p = 0.76). Despite the teams classified as "best-ranking" (1st to 8th position: 50.60 ± 10.35%) presented greater possession (EF=moderate) than "worst-ranking" (9st to 20th position: 47.59 ± 9.74%), no significant differences were found in the comparisons of match status (winner [50.34 ± 10.48%] x drawer [49.95 ± 10.25%] x loser [49.68 ± 10.48%]). Conclusion: General interpretations should be viewed with caution, since this possession can represent an indicator of success for a team but not for others.(AU)