Crushing the "Bro Split" Myth
Crushing the "Bro Split" Myth
Since the dawn of time there have been two warring parties.

The first party is the Bro-scientist (Bro). The Bro uses anecdotal evidence presented as fact by unqualified (yet confident) individuals in the bodybuilding community. These lifters use their physiques as evidence, regardless of how the results were achieved.

The broscientist will assume that what works for them will work for the majority. They resort to quoting information passed down from as long ago as the 80's. Broscientists usually fail to take into consideration pharmaceutical use of drugs or genetics as being major factors in their success.

The second party is the armchair scientist (Geek). The Geek has no professional training in science. Notwithstanding, he/she has the same augmented ego and clout (and on occasion, the same amount of knowledge on the subject) as someone qualified.

Distinguished by quoting abstracts without actually knowing the shortcomings and controls of a study, the Geek is usually unwilling or unable to adapt what is written in this research to an individual.

Two Bros Curling
The broscientist will assume that what works for them will work for the majority.

A Look at the 4 Day Bro Split

This part will discuss the "Bro split", otherwise known as the 4-day split. The aim of this section is to discuss the issues and misconceptions held about this routine by both parties.

The typical Broscientist will list the positives of this 4 day routine as the following:
  • Each muscle gets maximal rest
  • Hitting a muscle more than once per week will hinder gains in lean body mass, making the bro split a superior choice.
The Geek will say that the frequency is too low, and that higher frequency training has been shown to improve lean body mass and promote greater strength increases. These claims are true, but I'm going to demonstrate how these premises may or may not apply to the 4-day split.

A bit of preparatory information first. Virtually all pulling exercises will hit the biceps. On the same note, pushing exercises will hit the triceps. Movements like the bent over row, for example, will normally hit the back, biceps, and rear delts.

Muscle GeekEvidence for the Geeks

Look at EMG data compiled by Bret Contreras, along with the research from Boeckh-Behrens & Buskies (2000).

Another study also worth looking at is: "Effect of adding single-joint exercises to a multi-joint exercise resistance-training program on strength and hypertrophy in untrained subjects".

This research revealed the impact of compound exercises. Novices received so much stimulation from compound exercises that the isolation exercises added no significant difference in growth. N.B.

This was with novices, but it still indicates that the arms were getting sufficient stimulation to grow from compounds alone.

Evidence for the Bros

Simply measure your arms cold. Then measure them again after shoulder day. You should see a noticeable difference in the size of your triceps.

An Examination of the Bro Split vs. High Frequency Splits

We will now examine the 4-day split as well as two other "high frequency" training splits.
4 Day Split
Total = 13
4 Day Split Chest/Triceps Back/Biceps Shoulders Legs/Abs Total
Biceps X 1
Triceps X X 2
Front Delt X X 2
Middle Delt X 1
Rear Delt X X 2
Legs X (DL) X 2
Abs X 1
Back X 1
Chest X 1
Muscular Bodybuilder
Both groups are too elitist to take points from one another. The program will only be as good as the programmer.
Total = 20
Upper/Lower Upper Lower Upper Lower Total
Biceps X X 2
Triceps X X 2
Front Delt X X 2
Middle Delt X X 2
Rear Delt X X 2
Legs X (DL) X X (DL) X 4
Abs X X 2
Back X X 2
Chest X X 2
Push Pull Legs
Total = 13
PPL 4 Day Push Pull Legs Push Total
Biceps X 1
Triceps X X 2
Front Delt X X 2
Middle Delt X 1
Rear Delt X (DL) 1
Legs X (DL) X 2
Abs X 1
Back X 1
Chest X X 2
Even if I took the Deadlift (DL) out of back/pull days, it would have made little difference. As you can see, there is a lot of crossover and substantial frequency in the 4-day split. Ironically, the PPL (push/pull/legs) scored the same. This may even out slightly over a 2 week period as the cycle repeats.

If you truly think that a muscle needs time to recover, setting up a 4-day split may not be the best way to do this. If you look closely you see there are several days wherein you are hitting the same muscles on consecutive days.

Ironically, the PPL is more split than the 4-day split with regards to crossover.

Cable Triceps ExtensionsBros and Lagging Body Parts

I found this very interesting. There are two main ways I have seen Bros address lagging body parts.
  1. Adding a specialist day like an arm day.
  2. Increasing volume.
I have always found adding an arm day to be very ironic. This is because doing so increases frequency, a principle most Bros are against due to the alleged impact on recovery and the accompanying fear of going catabolic.

You will hear something like:
"I don't get enough stimulation so I added an arm day."
How did these muscles become different? Why do normal hypertrophy rules do no longer apply? Or perhaps you have simply added in more arm frequency and weekly volume because it means extra growth.

The second option, as mentioned, is adding volume. Perhaps it was stagnating because you failed to "punish" this muscle enough.

Another way to look at this is to look at the programming. Perhaps certain body parts were not allocated sufficient volume. Therefore, increasing volume on all parts pushed this lagging part's volume from moderate stimulation to high stimulation (albeit at the possible expense of recovery). This is more of a shotgun blast approach than a fine tuning.

Who Wins: Bro or Geek?

Nobody wins.

Both groups are too elitist to take points from one another. The program will only be as good as the programmer. The fact that most programmers fail to recognize what is going on here leaves an extremely limited opportunity to tweak the program for recovery, or to cater to lagging body parts and an individual's needs.

This is truly a shame.

How to Use This Information

Well, if you're doing a 4-day split you are not limited to only split body parts. For example, if your triceps are lagging, instead of adding 1-2 extra isolations to your triceps day why not add a triceps isolation exercise to your shoulder day to maximize efficiency?

Another good example: you could switch the order of days. If your squat is lagging, for example, perhaps doing heavy deadlifts the day before (thus fatiguing your legs and lower back prior to squatting) is unwise. At least now you can consider a better place to have a day off training.

The Geeks should also take note when critiquing a "Bro split." Technically it is not low frequency when compared to a 4-day PPL. Most Geeks who write their own routines have possibly more crossover issues due to a lack of biomechanical understanding.

Learning this will allow you to write better routines.