So, I'm 5'6 and 145 pounds. I initially wanted to lose weight to make featherweight, but now I'm thinking maybe I'll just burn off the fat I have and build muscle on that. And upon building muscle, I'll probably gain weight, putting myself into lightweight. So I need to gain some pounds. About 20. My friend Victor is this HUGE guy, he's about 192 and is nothing but muscle. He tells me he got big from circuit training. Should I do this, or is there something else that would be better for me to get bigger, or something better for an MMA fighter.
What's the best way to gain weight by ONLY building muscle?
PS. I currently do crossfit. My friend tells me its good for endurance, and will get me lean but won't really have me gain as much wait as I'm looking into gaining. What do you think?