You’ve gotten past novitiate weightlifting aches, enduring 4+ sessions weekly. How should you now split exercises across days?

My answer is: use the posterior-anterior split. One day for the muscles used in a deadlift (back, hamstrings, glutes) plus biceps, one day for more-or-less everything else (chest, front- and side-delts, triceps, quads, hip flexors).

Here’s why.

The goal

We want to train muscle groups as intensively as possible, as frequently as possible, whilst not training the same muscle group within fewer than 48 hours. (Plus injury and personal constraints.)

The usual advice

Conventional wisdom offers 1 of 4 blueprints:

1. Bro split (1 narrow muscle group per workout).
2. Push/pull/legs split (chest, front- and side-delts, triceps one day, back and biceps the next, legs to finish).
3. Upper/lower split (upper body one day, lower body the next).
4. Full body split (all muscle groups every workout).

The usual advice is wrong

1. Bro splits take too extreme a position on the intensity/frequency trade-off. Ditto for full-body splits. Lesser ditto for push/pull/legs. If you’re trying to train muscle groups as often as possible whilst not training the same muscle group within fewer than 48 hours, the best split will involve training each muscle group every 48 hours (sans rest).
2. Both push/pull/legs splits and upper/lower splits hit the same muscle group on consecutive days. Deadlift-style movements work the entire posterior chain – back, hamstrings, and glutes – so pull or upper day will necessarily conflict with a consecutive legs day.
3. Both push/pull/legs splits and upper/lower splits have a dedicated leg day. Needlessly unpleasant!

The solution

We need a 2-part split that cleanly separates deadlift-style movements from everything else, without a dedicated leg day. This is the posterior-anterior split!

Biceps on posterior day is mandatory because of the back movements. If you’re into neck or forearm training, do it on posterior day. Abs should probably be on anterior day exercise because abs go well with hip flexors. Side-delts and calves are flexible – I’d do them on anterior day.

Obligatory caveats

1. None of this makes sense if you want to or should take a rest day between every workout – go for full-body.
2. If you’re not yet in the habit, the best split is the one that gets you to show up to the gym at all.
3. If I did not exercise yesterday and can not exercise tomorrow, I will go for weak points only, or full body, or whatever’s most fun.
4. If I’m regularly playing soccer, I will do legs the day afterwards/make sure to never do any legs within 3 days beforehand.