People have asked me what they can do with a balanced 4-day/week exercise program. My reaction has been that 4 days isn't ideal. But...
If you work out, say, 4 1/2 hours weekly (on 4 days) you can maintain or improve your physical condition, so it is worth doing if you have ambition limits, time limits, or need rest days. Way better than nothing but you will probably be disappointed by the pace of your gains compared to a 6 day program.
Here's what we would suggest:
-2 conditioning classes/week (combo of calisthenics, cardio, and light weights). If gym-phobic, it's difficult to do on one's own. Long-time readers know what these sorts of classes involve.
- 2 half-hour sessions of powerlifts (squats, bench, and rows one day; deads, pull-downs, and triceps the other) coupled with 2 half-hour sessions of HIIT cardio - no time for long slow - plus two 15-min sessions of selected auxiliary exercises
- If daily walks, jogs, or some sports are also in your life, you would be doing more exertion than most people.