The best three-day workout routine is the one you're going to do three days a week. It's absolutely pointless to embark on a fitness program, with a well researched list of exercises for a three day workout routine, if you're not going to do it consistently, three days a week. I'm emphasizing “three” because it’s a screaming deal if you can get away with it.
Devoting a three-day workout routine to a seven day week is a pretty paltry commitment, considering what you intend to accomplish.
And that's really the issue. What is the purpose of this fitness program?
If your goal is to build a bodybuilder physique, there is pretty much little you can do with a three-day routine of even the best mass building workouts. Unless you can commit to training all day long for those three days, building mass with just a three day workout routine is going to be, for most people, disappointing.
That's not to say it can't be done.
Certainly, there are bodybuilders who have applied the high intensity training philosophy to their bodybuilding workout plan, and were able to pack on some mass, as well as gain strength.
But, they are the exception, not the rule. The level of intensity you'd have to generate to pack on mass in just three days a week is legendary to say the least; not many people can do it, at least not long enough for it to bear fruit.
If that's still the direction you want to go, then the list of exercises you're going to do is pretty small.
You're going to have to stick to the basic compound exercises and train your body to failure every time you train.
Like I said, the list of exercises is going to be small.
A three-day workout routine would be split into two days, focussing on your upper body; one of those days devoted to pulling moves, and the other to pushing. The third day would be legs.
Your routine would look something like this:
Monday – Upper Body - Push:
Seated Shoulder Press
Rope Triceps Extensions
Tuesday – OFF
Wednesday – Upper Body - Pull:
Seated Pulley Rows
Thursday – OFF
Friday – Legs:
Saturday – OFF
Sunday – OFF
Sets and reps are going to vary based on the individuals, their level of training, and the time available to spend in the gym. You also have to remember, there's a time commitment for food shopping, meal prep, and rest. There's also no allotment for cardio. If you intend to gain strength and muscle mass with just a three-day a week commitment, you're going to have to cover all the bases and make the time you do spend in the gym count.