^^^ Ah yes you need to find the balance. It's no good if your legs are sore as hell from weight training and you've got to throw all kinds of kicks or do any conditioning work, even jumping rope can be quite a challenge if you've been to the gym the day before. It goes both ways, I used to train Muay Thai 3 to 4 times a week and found that I had almost no energy to lift seriously. Any extra energy I'd rather spend on extra cardio like running.
But alas, I can no longer train muay thai as I have since moved away. I train 2 nights of kickboxing a week. However with access to two gyms, one 2 minutes away from my house and one in my colledge, I weight train allot now. Honestly, I don't do it to be a better martial artist, I do it to look good for the ladies, and as a substitute for training...but mostly for the ladies. Hey us single males got to look our best right?...right?