Worldwide, soccer has grown increasingly popular among female players. According to the Women´s Football Survey of the Fédération Internationale de Football Association (FIFA), there were more than 30 million registered women soccer players in 2014. Elite female soccer players cover approximately a total distance of 10 km with 1.7 km completed at high-speed (>18 km/h-1), between 1350 and 1650 changes of activity like passing, dribbling, tackling and trapping and 5.1 and 31.2 repeated sprinting and high intensity bouts, respectively. Thus, it seems that those strategies addressed to improve such high-intensity activities should be considered a priority for female soccer players.

Different training methods to improve soccer specific variables have been developed such as, high-intensity interval training, resisted sprint training, strength training or plyometric training. Whilst individual training interventions have been shown to produce enhancements in measures of athletic performance for soccer players, there is a paucity of studies looking at the effectiveness of strength and power training specifically on performance measures in female soccer populations.

Unilateral strength asymmetry can be a risk factor of musculoskeletal injuries. In recent years, inter-limb asymmetries have been included in battery tests performed by different soccer clubs due to their relation with lower-limb injuries. Few studies have analysed the change of an intervention on inter-limb asymmetry in female soccer players, hence, more studies for this population are warranted.

The main aim of this research project is therefore, to evaluate the effect of a physical intervention on the performance and inter-limb asymmetries of female soccer players.

Inclusion Criteria:

• Caucasian, Healthy participant, from 12 to 20 years old, with a history of training at least 3 years.

Exclusion Criteria:

• Non-caucasian, injury.