Salbutamol is a β2 adrenergic agonist widely used for the treatment of asthma and known to reduce plasma potassium concentration [K+]. The International Olympic Committee had been concerned that salbutamol may give an inequitable advantage to athletes. However, little work has investigated whether salbutamol has beneficial effects on plasma [K+], K+ dynamics during exercise and how these potential changes may impact on exercise performance. This study investigated the effects of salbutamol on K+ regulation at rest, during repeat sprint exercise was also explored.