Effects of Strength Training on Cognitive Function, Brain-Derived Neurotrophic Factor and Insulin-Like Growth Factor 1 in Highly-Trained Young Female Soccer Players

BACKGROUND: Female soccer continues to gain global popularity. Selected components of physical fitness (e.g., muscle power, change-of-direction [CoD] speed) and cognitive function (e.g., attentional demand, training-induced) play an important role in soccer performance and should, therefore, be systematically developed. OBJECTIVES: In this study, we examined the effects of 12 weeks of strength training (ST) on selected measures of physical fitness, soccer performance, cognitive function, and selected markers of neuroplasticity in young female soccer players. METHODS: Twenty-two highly-trained female soccer players with Tier 3 training and performance caliber aged 14.9±0.8 years were randomly assigned to a strength training group (SG: n = 11) or an active control group (CG: n = 11). During the training period, SG performed two weekly upper and lower body ST sessions (3 sets, 12 repetitions per set) at an intensity of 60-80% of the one-repetition-maximum (1-RM) and three soccer-specific training sessions (tactical-technical drills). Players from CG continued their regular soccer-specific training routine consisting of five weekly sessions. Training volumes were similar between groups. Pre- and post-training tests were conducted for the assessment of body composition (e.g., body mass, skinfold site measurements), muscle strength (1-RM bench press/Lat pull-down/leg press),the Loughborough Soccer Passing Test (LSPT), cognitive function (Stroop test), and selected markers of blood neurotrophins, such as basal brain-derived neurotrophic factor (BDNF) and insulin-like growth factor 1 (IGF-1) serum concentrations. RESULTS: =0.00-0.04). CONCLUSIONS: A 12-week in-season ST program with two weekly sessions improved measures of physical fitness, soccer-specific performance, and cognitive function but not biomarkers of neuroplasticity in young highly-trained female soccer players. Accordingly, we recommend ST should be implemented to improve physical fitness and cognitive function of young female soccer athletes.