The French athletes prepared in the INSEP TTR in order to acclimate to the heat of the Japanese archipelago and avoid the heatstroke on the day of the competition.

Below is the link to Morhad Amdouni's testimony (European champion of the 10 000 meters) at FranceInfoyes

https://www.francetvinfo.fr/les-jeux-olympiques/jo-de-tokyo-2021-des-athletes-francais-s-entrainent-dans-une-salle-thermique-pour-recreer-les-conditions-meteos-japonaises_4689641.html