According to Bloodstain Lane, the leading purveyor of the scientific study of machismo, Ubereem's machismo levels were running at an all-time high going into his fight against Bigfoot Silva at UFC 156. Unfortunately machismo does not necessarily equate to testosterone, which Alistair Overeem severely lacked. According to an article written by Dave Meltzer of MMA Fighting, Overeem's testosterone levels were dangerously low going into UFC 156, which would make him not perform at his athletic peak.
Overeem, the 262-pound heavyweight with the Herculean physique came back with a blood testosterone level reading of 179 nanograms per deciliter, a figure that would be considered dangerously low for a competitive athlete.
Overeem's test, taken the morning after the fight, was low enough that most doctors would recommend him to be on a testosterone replacement plan even if he was not an athlete, and would at least in theory, make it very difficult to have the energy to get through a productive training camp or fight at peak efficiency.
It's also important to note that if you're a convicted user of steroids, then being granted a license to use TRT would be impossible. Of course, it's also important to note that the Reem never tested positive for steroids -- just an elevated level of testosterone leading up to his title fight against Junior dos Santos back in 2011.