Association between supervised strength session attendance and isokinetic recovery trajectory in male footballers following ACL reconstruction: a 6-year retrospective cohort study
Chaouachi A, Farooq A, Carruthers T, Ogden A, Sagarra A, Thomas C, Marques J, Nascimento N, Nuccio S, Whiteley R, Buchheit M. Association between supervised strength session attendance and isokinetic recovery trajectory in male footballers following ACL reconstruction: a 6-year retrospective cohort study. Sport Performance & Science Reports. 2026; May; 297; v1.
New paper from the Aspetar ACL rehabilitation program. 55 male footballers, 6 years of data.
All hamstring autograft reconstructions. Between weeks 12 and 18 post-surgery, athletes attending 2 or more supervised strength sessions per week reached a quadriceps limb symmetry index of 96% by week 18.
Those attending none or one stayed around 79%. A 17 percentage point gap. Effect size d = 1.86. That is the difference between meeting and not meeting a key return-to-sport benchmark at that time point.
By week 24 the gap had largely narrowed, so lower attendance does not permanently derail recovery. But in elite football, every week below criteria carries real cost. One important nuance: “0 sessions” does not simply mean non-compliant athletes. In a criteria-based pathway, some players were not yet ready to transition to supervised strength work. The comparison is partly between those who progressed on schedule and those who needed more time first.
That distinction matters for interpretation. For hamstrings, the picture is different — and the graft choice matters here. In a hamstring autograft reconstruction, the donor muscle undergoes its own recovery driven by graft healing and morphological factors. No clear dose-response pattern emerged for hamstring isokinetic recovery. This is likely not a volume problem. Exercise selection, particularly targeted eccentric and high-velocity loading, is probably more important than simply attending more sessions.
The practical message: the 12-to-18 week window is a high-leverage period for quadriceps recovery. Supervised strength session attendance is a clinical variable, not an administrative one. Track it. Discuss it with players. Support engagement actively.
👏 Huge team effort: Anis Chaouachi, Abdulaziz Farooq, Thomas Carruthers, Archie Ogden, Andres Sagarra, Christopher Thomas, Joao Marques, Nuno Nascimento, Stefano Nuccio, and Rod Whiteley. Thanks also to the RAMAL team at Aspetar for their support throughout.
