I'm aiming to gain a decent amount of lean mass over the next 6 months. I haven't had a lot of luck with this because I'm very much the lean and skinny weakling build, but also because I deal with fatigue a few times a year that throws a wrench in the Crossfit/HIIT approach I've been trying. The last two times I tried a regular HIIT workout, I had fatigue flareups within 2 months that destroyed my progress.
One complication is that I usually go LC/VLC except for post-workout to manage my fatigue.
Any ideas or suggestions?