Best vs Worst Workout Splits to Build Muscle

What’s the best workout split for muscle growth? Worst? In this video, I’ll be ranking 7 of the most popular workout routines (from the upper lower split workout to push pull legs to bro split) to find the top performers all the way down to the ones that are wasting your time. I’ll also add a bonus factor; time efficiency, to see which split gets you the most gains in the least time.

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Together with PhD researcher Eric Trexler, we used the latest research to build a predictive growth equation focused on 2 key factors: frequency and volume. The best workout split will strike the perfect balance of both.

Let’s start with a classic, the push pull legs split. I’ll score the 3-day per week version first, which came up to a hypertrophy score of 6.7.

Next up, the 3-day full body workout split. A major advantage it offers is that training a muscle 3 times per week may boost strength gains by about 50% compared to training it once weekly—even with the same weekly volume. How much does this help muscle growth though? While the latest data suggests frequency doesn’t seem to be as important for growth, it still helps provide a small boost. Enough for it to score 8.1.

Next, the classic upper/lower split workout. Each muscle is hit just twice per week. However, this split does allow for an extra workout day, meaning you can fit in more volume — and that may be a bigger driver of growth. Because of this, the upper/lower split scores quite well with a 8.4.

Time to step things up with the 5-day workout routines. Starting with the Upper/Lower/Push/Pull/Legs split. The beauty about this hybrid routine is that it allows you to fit in more volume than the 4 day upper lower split, but doesn’t come with the big time commitment of something like a 6 day push pull legs split. It comes in with a hypertrophy score of 9.0.

Moving onto the classic 5-day bro split. One criticism of the bro-split is the idea of “junk volume”. Because you’re doing so much volume per workout for just 1 muscle, by the time you reach your 3rd or 4th exercise in your workout, your performance drops considerably. But we definitely need more research to see just how much of a difference this would make. For now, let’s see how it scores. It slides into a close second place with a score of 8.8.

Alright next up we have the 5-day full body workout routine. Now although this sounds like a bad idea, in each workout you’re only doing a few sets per muscle. Allowing you to push hard during those sets yet still recover well even if you’re training that same muscle the very next day. But what’s really interesting is this style of training may provide additional benefits for growth, especially as you get more advanced. In beginners, the muscle protein syntehsis response lasts about 48 to 72 hours. In advanced lifters, however, this shortens to just 12-24 hours. Because of this, advanced lifters may benefit from higher-frequency splits to avoid any “downtimes” where muscles aren’t being signaled to grow.

But, this is all just theoretical. The real question is does this really lead to more growth?
Well, one study published back in 2019 on trained lifters found that after 8 weeks, almost every muscle measured grew more with the full-body workout split compared to the bro-split. And as for its hypertrophy score, after crunching the numbers it scores an all-time high of 10.0, taking the top spot by a longshot.

But there’s one more split left: the 6-day push pull legs split. Although this routine trains each muscle only twice per week, you are able to fit in a ton of volume because of how many days you’re in the gym. After crunching the numbers, it comes in at a close second with a score of 9.7.

Unless you’re someone who would live, eat, and sleep in the gym if it meant more gains, you should also consider time efficiency. And I don’t just mean how many days a week you workout. There’s other factors you need to consider, like warm up sets. Full body workouts are usually longer because you have to take time warming up both your upper and lower body. It’s one of the reasons why despite the 5 day full body routine having the highest hypertrophy score, I personally still choose not to use it.

So, the real question becomes: which split offers the best gains for the least time commitment? To answer that, we calculated the weekly time investment you’d spend on each split and compared it to its hypertrophy score. We found one split that gives you 85% of the gains of the top split but with 30% less time in the gym every week. And that split is...the 4-day upper/lower split.