I gained a little bit of weight with STS, mostly fat. I'm sure some of it was muscle, as I did increase my upper body strength, but I also developed a bit of a "muffin top" for the first time in my life -- i.e. visible fat! I think the fat gain was mostly related to reducing my cardio. STS really took it out of me energy-wise and at first, I was often too tired, or too sore, to do my normal cardio load, so I went from 5 cardio sessions per week to 2. I was also dealing with IT Band syndrome which meant I had to ease off on my leg workouts. By the time I got into my groove and was no longer too tired or sore, I'd gotten into some bad habits and didn't put my cardio back up. This past December, I finally kicked up my workouts again and now the fluff around my waist is just about gone.
I'm just about ready to try another cycle of STS. This time I know I need to stay disciplined and keep my cardio up, and the fat should stay off. Getting some discipline in my eating habits should help too.
Are you doing STS, or planning to do it?
Stebby