Originally Posted by AkiraInThailand
No you shouldn't be weight training. Muay thai fighters need quick muscles to move fast, not big ones. This will also cause some stiffening of your muscles and body, and slow you down. Rather than weight training I would be running a lot, 4-6 kms a day if you can.
this is virtually complete bs, running is good advice and gaining muscle mass will cause your cardiovascular system to be taxed more as the bigger your muscles are the more oxygen they will need to do the same 'time' of effort.
But muscles don't make you slow or ponderous, that is basically the Martial Arts equivalent of an old wives tale
and even if larger muscles did have negative impacts on your martial abilities, you can lift weights to improve strength or endurance without specifically targeting hypertrophy
I would wait until your body is as accustomed to the martial arts training as you can before taking up the weights tho