Cooling at Tokyo 2020(1): the why and how for endurance and team sport athletes.

The Tokyo 2020(1) Olympics are expected to be the hottest in modern history,1 resulting in much conjecture within the literature.2–5 Long-term (~10 to 14 days) heat acclimation/acclimatisation (HA) is the gold-standard strategy to protect against heat-mediated performance decrements and exertional heat illnesses (EHI).6 Short-term heat reacclimation (~5 days), proximal to competition, can also be incorporated within athlete training and taper programmes, complimenting the earlier long-term HA. This approach allows the balance of training/load and HA agendas within the often time poor and logistically challenging elite sport environment.5 7 8 With the assumption that athletes arrive robustly heat acclimated/acclimatised to Tokyo 2020(1), practitioners have a variety of precooling, during(mid) and postcooling event interventions to consider on competition day – that are complimentarily to – rather than instead of HA.8 In brief, these can include various combinations of: (i) internal (ice slurry ingestion, cold water ingestion, etc) and external (any cold fluid, medium or air source the body is immersed or exposed to) body cooling interventions to reduce body tissue temperatures [eg, core (Tc), muscle (Tmu) and skin (Tsk) temperature (see figure 1 for summary)]8–10; (ii) interventions to evoke local cooling sensations (eg, menthol mouth rinse) which could be favourably interpreted (ie, their perception) by higher brain centres without altering Tc11 and (iii) titration of competition warm-up procedures and/or alterations in pacing, tactics and/or strategy. At the recent 2019 IAAF World Athletics Championships (Doha, Qatar), LT …