The aims of this clinical study are evaluated the effects of Blood Flood Restriction training on the sport performance of professional and semi-professional soccer players. The participants are twenty male professional and semi-professional soccer players who are playing at RCD Mallorca. Participants will be assigned in two different groups. Both groups develop for six weeks a strength training programs. The first group will base their training in Low Load using Blood Flow Restriction (20-50% of one maximum repetition). The second group will base their training in High Load (60-80% of one maximum repetition). This training program includes three type of exercises in each training session; back squat, single deadlift and barbell hip thrust. Before and after this program the investigators will collect sociodemographic and anthropometrics data. On top of that, the investigators will evaluate the muscle mass, the electrical activity produced by skeletal muscles, the muscle strength and the sprint ability of every participant. Before to the evaluation, the soccer players will warm-up during 15 minutes under the control of the evaluators.

PARTICIPANTS:

Participants are soccer players of RCD Mallorca (Second Spanish Football Division) and RCD Mallorca B (Third Spanish Football Division).Before to start the study, every participant will receive an informed consent about the clinical study. This informed consent will be signed by them according to Declaration of Helsinki. At the same time, the data will be anonymized and only the main researcher of the study will have access to it, to ensure compliance with the Data Protection Law.

W-UP:

The warm-up will consist of 5 minutes running slow (treadmill), 5 minutes mobility, and 5 minutes of running exercises. In addition, the warm-up will contain a familiarization with the jump test

Inclusion Criteria:

• No injuries in the last 6 months
• 1 years experience minimun in the division.

Exclusion Criteria:

• Amateurs players