Physiological and performance responses to the FIFA 11+ (part 2): a randomised controlled trial on the training effects

The aim of this study was to examine the training effects of an injury prevention programme on neuromuscular control, strength and performance in male amateur football players. Eighty-one players were allocated to the "FIFA 11+" (n = 42) or a control group (CON, n = 39). The "FIFA 11+" group performed the programme 3 times a week for 9 weeks; the control group completed the usual warm-up. Primary outcomes were: time-to-stabilisation test and eccentric/concentric flexors strength. Secondary outcomes were: eccentric/concentric extensors strength, star excursion balance test, core-stability test, vertical jump, sprint, and agility. After controlling for covariates, significant between-group differences after the intervention (in favour of the "FIFA 11+" players) were found for time-to-stabilisation (-2.8%, 90% confidence interval [CI] -4.4 to -1.2%) and core-stability (-8.9%, -14.6 to -3.1%). Differences were also found for eccentric (3.8%, 1.4 to 6.2%) and concentric flexors strength (3.2%, 0.6 to 5.9%) at 60° · s(-1) but this difference was only possibly meaningful (62.4%) from a practical point of view. No substantial and/or significant differences were found for the other outcomes. Performing "FIFA 11+" for 9 weeks can improve neuromuscular control. Possible worthwhile differences were found for flexors strength but there were no substantial effects in the other performance measures.