“Tour de France” Sanchis-Gomar et al.Have in Int J Sports Med. 2011 Aug; 32 (8): 644-7 published a job that shows that former wheel professionals live significantly longer compared to the average population.
Hard training in the extreme area does not seem to be harmful, but on the contrary to extend life. The abstract can be found under https://pubmed.ncbi.nlm.nih.gov/21618162/