Strength development according with age and position: a 10-year study of 570 soccer players

Background/aim The purpose of this study was to compare the isokinetic peak torque profiles from the quadriceps and hamstrings muscles during concentric and eccentric contractions in elite Brazilian soccer players across different field positions and age categories. Our hypothesis was that soccer players from different field positions are subjected to different ageing-related effects on their isokinetic peak torque. Methods This is a retrospective study based on professional elite-level soccer players between the years 2009 and 2019. It included 570 adult males who played for at least 5 years on first or second Brazilian divisions. Playing positions were divided as: goalkeepers, defenders, sidebacks, midfielders and forwards. Age categories were also divided as: G1 (17-20 years old), G2 (21-24 years old), G3 (25-28 years old), G4 (29-32 years old) and G5 (33 years old or more). Results The results indicate a moderate effect of age (F(4545)=8.197; p<0.001; Î • 2 =0.057) and a small effect of playing position (F(4545)=2.993; p<0.05; Î • 2 =0.021) on torque of concentric extensors; mainly from midfielders and goalkeepers with 29 years or more. Conclusions Soccer players from different field positions are subjected to different ageing related effects on their muscular performance during their career special attention should be given to these players to avoid reduction in physical performance.