I've been doing the 24 workout mass blitz program by Jacob Wilson:
The program is working GREAT. I had been out of serious lifting for a good two years, and I've already noticed visible gains halfway through the program. My DOMS last only a day or two at most now, as opposed to 5 days at the beginning. I'm wondering if it would be advisable to workout on the off days, and what kind of exercise would be beneficial during this program? I'm already at the gym on my off days helping my fiance with her strength training, and I always have the urge to work out. I'm just worried that if I start doing cardio it will hinder my growth.