Yes, I am familiar with that and they basically use it to break people and get them in shape. Let's be fair, the majority of people who join the military aren't necessarily in top notch shape to begin with so it's not that hard to do.
My old Muay Thai coach was a former marine drill sergeant and we did their work outs as "warm ups". Given it was a more than needed 30 minute warm up. Then you have people come out the core and try to train to fight and they can't hang the full length. It's a completely different situation. I'm just saying you cannot compare a boot camp to defending your title against a hall of fame boxer.
Either way, if you think 4 vials is nothing then I applaud you. As for me, I rather not give up a drop of blood if I don't have to because personally I feel my stamina lack and I get light headed a lot quicker.