Several studies have shown that football practice regulates bone remodeling, producing an increase of bone mineral density and reducing the risk of fractures. Thus, the aim of this study is to evaluate the effect of football practice on the regulation of bone turnover in Spanish adult football players. Thanks to the collaboration agreement "Aula Endavant" the Villarreal CF participates as a collaborator in this Project. This agreement allows us to use their facilities and to analyze several football players' data.

Several studies have shown that football practice regulates bone remodeling, producing an increase of bone mineral density and reducing the risk of fractures. These studies are mainly performed in adolescents and there are few results obtained from European adults subjects. Thus, the aim of this study is to evaluate the effect of football practice on the regulation of bone turnover in Spanish adult football players. Secondary objectives include: describing bone mineral density values, evaluating percentage of total lean mass and body fat, describing dietary and physical habits and analyzing blood tests of professional football players. As well as, they include updating the current state of knowledge of the influence of sports on bone. Thanks to the collaboration agreement "Aula Endavant" the Villarreal CF participates as a collaborator in this Project. This agreement allows us to use their facilities and to analyze several football players' data. In addition, different members of the club will directly participate as researchers during the development of this study.

One of the strengths of this study is that the data were obtained from two consecutive seasons of an elite soccer team.

One of the potential limitations that we have faced in this study is that in order to obtain a large sample, it is necessary to analyse the soccers from two consecutive seasons, which makes the study temporarily longer than desired.

Inclusion Criteria:

• male gender
• aged between 18 and 40 years
• who practice soccer for more than 6 hours / week from the age of 10 to the present.

Exclusion Criteria:

• play other elite sports than soccer
• play 6 or more hours of recreational sports per week
• smokers
• individuals with chronic cardiovascular diseases, hypo and hyperthyroidism, hypertension, rheumatoid arthritis and osteoarthritis

male professional soccer players playing in the top soccer championship in Spain