Jamie

Given that Muay Thai is a major destructive martial art, a solid course of gear accompanied with a specific weights program will without doubt improve your ability. You could improve your explosive power, which would transfer well both to your training and any sticky situation you might find yourself in.

However, take a look at all the Thai's who could run rings around you, whilst taking you apart with no real effort. None of them really look as if they hit the gear, especially in the same manner as a bodybuilder would anyway. Stimulants on the other hand do come in handy, especially if you get serious enough to ever try your hand at training with weapons.