Hydration for the Tokyo Olympics: to thirst or not to thirst?

Endurance and team-sport athletes competing at the 2021 Tokyo Olympics Games can expect hot and humid conditions. Ensuring euhydration prior to an event and minimising dehydration during competition will be important, to ensure an optimal physiological state and competitive advantage.1 Contention exists, however, regarding a primary recommendation provided to athletes: drink to thirst or plan to drink. The debate is centred on the level of dehydration that can be incurred prior to its effects influencing physiological responses and performance.2