True story. I recently kickstarted with weighted calisthenics at home (Chins, dips, handstand push ups, squats, etc.). And I found that pushing my body every 2-3 days hard for 2 sets per exercise is all that I need to make small small progress. I tried running the whole high volume high rep style training. In 2 weeks, I lost some mass. But active rest, proper diet and hard training (gym or weighted calisthenics) 2-3X a week, I'm sure can take most average working people far enough.