MuscleTech sponsors professional competitive bodybuilders Santi Aragon and Marc Megna, both of whom incorporate this product into their workout routines. Santi Aragon is an International Federation of Bodybuilding and Fitness professional bodybuilder who has won a number of top-level NPC shows in recent years including the Nationals, Southern States, USA Championships and Teen Nationals. Marc Megna is a personal trainer and coach who formerly played professional football in both the CFL and the NFL and is a regular columnist in major men’s fitness magazines.
The second theory is similar and is known as "evolutionary neuroandrogenic (ENA) theory of male aggression".   Testosterone and other androgens have evolved to masculinize a brain in order to be competitive even to the point of risking harm to the person and others. By doing so, individuals with masculinized brains as a result of pre-natal and adult life testosterone and androgens enhance their resource acquiring abilities in order to survive, attract and copulate with mates as much as possible.  The masculinization of the brain is not just mediated by testosterone levels at the adult stage, but also testosterone exposure in the womb as a fetus. Higher pre-natal testosterone indicated by a low digit ratio as well as adult testosterone levels increased risk of fouls or aggression among male players in a soccer game.  Studies have also found higher pre-natal testosterone or lower digit ratio to be correlated with higher aggression in males.