That depends upon the density of your work outs. If you are resting one minute between high rep sets, an hour sounds fine. But I have to rest three to four minutes between many of my sets, especially full body, compound motions. I don't know how much of that is due to getting older or lifting more weight. If you include my squat ramp ups with my squat complex sets, that part of my workout can take me over a half hour.
And are you thin trying to build muscle or trying to lose weight? I have to exercise an hour and a quarter to an hour and a half to kick up my metabolism so I'm still burning fat outside the gym.