It went down as one of the most fateful training camp decisions in mixed martial arts history.
Fabricio Werdum chose to train in the mountains above Toluca, Mexico, elevation 8,730 feet, for six weeks before his UFC 188 matchup with Cain Velasquez.
Then-UFC heavyweight champion Velasquez stayed in San Jose, Calif. for most of his training camp for the bout in Mexico City, elevation 7,380. He arrived in town two weeks before the fight.
On fight night in Arena Ciudad de Mexico, Velasquez, who had been out of action two years, started fast, faded, and was ultimately picked apart by Werdum before getting submitted in the third round and losing the title.