My physique is improving, i'm up to 200-205 lbs and my heavy lifts are also up(bench, squat and deadlift). But my stamina is way down. I know if i wasn't 'bodybuilding' and trying to gain weight, then i would start running or play a sport(can't play sports cause its winter) but what should i do once or twice a week that will help my overall stamina(GPP) while building muscle?
What does that mean? Competition or just looking good? Because if it's just to look good, why worry about 'building muscle' while doing a little cardio? Obviously if you stop doing aerobic work and pack on 20lbs your aerobic conditioning will suffer.
That said. Slowly building up to HIIT training or sprinting or hill climbing will help your endurance and have little effect on muscle maint.