One aspect besides the conditioning (which I believe is movement specific) is "slow", "medium" and "fast" twitch muscle fibers.

Fast can be turned to slow to a degree and medium to fast or slow to a degree but for the most part fast can't go to slow and once you change to slow you're pretty much stuck there.


If, as a child, you do endurance training or sport and as an adult you want to be in a power sport... well you already are limited by the amount of slow twitch you developed.

MuayThai is a power sport... running for hours creates muscle fibers that are good at endurance and, you guessed it, running for hours. Slow twitch muscle fibers, best used for going and going and going (at a lower intensity) are not great at explosiveness and power.

If you train power and endurance (not relative to sport your in - MuayThai 3 min - +2 min break for 5 rounds = 15 mins of action with 2 min breaks every 3 min - so running an hour for a 15 min event - with breaks) the muscles will go more towards slow twitch than fast (especially the mid)

Pretty much limited for life here...

Been a long time since I studied this but I think as a rough view that is pretty accurate.