Persistent physiological benefits from doping? Ethical implications for sports integrity.

The effects of some widely abused doping substances such as anabolic androgenic steroids (AAS) on performance are well-documented, particularly in the short-term, and the use of these substances is banned by various sporting authorities, with athletes sanctioned from competing for up to 4 years. However, controversy exists on whether residual physiological effects of some doping practices could persist even years after discontinuation, granting unfair advantages to athletes long after sanctions have been served. Particularly, in support of the so-called muscle memory theory, growing evidence in both animals and humans suggest that AAS administration could exert long-term effects at the muscle level, notably a higher number of myonuclei. This effect could enhance retraining/muscle remodelling capacity long after AAS cessation, thus supposing an advantage for doped athletes even +4 years after doping practices have been discontinued. If confirmed, the persistence of physiological improvements resulting from past doping practices raises serious ethical concerns in the sports field and opens the door to lifelong sanctions.