No one did cardio back then. If they did, it was slow paced jogging. That was back from the day when Jim Fixx was promoting jogging. Three days a week with weights worked well in my early twenties, but I also worked out 2.5 hours at a stretch with a lot of heavy lifting. I never tried three days with bodyweight, but I am sure it would work. You'd have to train at least 45 minutes at a stretch to cover all body areas. A better way could be to do pullups, pushups, situps and free squats two days, and self-resistance for the arms and shoulders for the other two workouts.