Originally Posted by kp2171
....first of all, muscle mass has nothing to do with minutes in the gym. it has to do with stress and hard reps.
your body wont build bigger mass unless you are increasing your weights over time. if you are still working with the same or nearly the same weights as you were before, why should your body make bigger muscles? it costs energy. it takes maintenance. you are trying to force your body to go against itself. this means really stressing the muscles. 8-12 reps, hard work. dont be doing the same weights a month or two later. you need to stack more on. if youve been working out your body should be broken in enough to be upping the weight and increasing the resistance.....
....so you need to really push your body, using good form, being safe. as gregr mentioned, if you are doing the same old routine and not getting results, then you need to amp up your routine.