A training split is a crucial part of a successful fitness routine, so let’s see what the research says about which one is best.
Brandon Hyatt, MS, CSCS
Dec. 04, 2024
Knowing how to do some exercises is one thing, but what is the best training split to incorporate them all into a concise and efficient routine? A training split is how the body's muscles are divided into groups, movements, or focus areas and put into a weekly routine. It’s a system where exercises are categorized to allow for tracking progress and alignment with goals.
Here are some typical training splits in no order of effectiveness:
- Chest, back, shoulders, arms, legs, abs
- Upper, lower
- Chest and triceps, back and biceps, shoulders, legs
- Push, pull, legs
- Push, pull, hinge, squat
- Full body
The list above contains several ways to categorize muscles and movements into a training split. But how do you know which suits you and is most approved by research? There are a few essential things to consider that can help you pick the right training split, so let’s talk about those. Then, we’ll dive into the research to see which training splits have the best outcomes for strength and hypertrophy.
Time
The first step is deciding how many days a week you can train. If you can only train three days per week, then some splits requiring a day for one or two muscles won’t fit in. Imagine a person new to lifting weights on a 5-day training split with a whole hour to train their chest. Due to their beginner training level, an entire hour of chest exercises would be too much and cause tremendous post-exercise muscle soreness. A 1-2 day training split will be much more appropriate since they can spread the training across multiple muscle groups.
Other Performance Goals
Other performance goals should be considered when selecting a training split so the body can recover and work on different goals throughout the week. For example, if a person aims to run twelve miles a week across three training sessions, a four- or five-day training split for strength and hypertrophy may make it challenging to recover and allow for the most effective training sessions.
Training Split Compared in Research
The following will discuss different peer-reviewed research studies that evaluated different training splits. Volume-equated training frequency is the primary variable manipulated in most of these studies since different training splits have different training frequencies on muscles.
Study 1
A 2021 study compared the effects of an eight-week volume-equated full-body (4 sessions a week per muscle group) versus a split routine (4 sessions a week per muscle group) on strength and hypertrophy in 67 untrained young males (1). Strength was assessed with a 1-RM bench press and a 1-RM Smith machine squat. Hypertrophy was measured with ultrasound imaging of the muscle thickness of the biceps, triceps, vastus lateralis, and rectus femoris.
Both routines resulted in similar gains in muscle strength and hypertrophy. Both training strategies are equally effective in untrained individuals during the early training phase (eight weeks). This study's findings show that various training splits can be used to optimize muscle strength and hypertrophy in the initial stages.
This study was limited to a short training period of untrained men whose nutritional intake was not monitored. Also, the muscle sites measured for hypertrophy were limited to only the arm and quads.
Study 2
A 2019 study compared the effects of a ten-week volume-equated full-body (3 sessions a week per muscle group) versus a split routine (2 sessions a week per muscle group) on strength and hypertrophy in 36 trained young males (2). Strength was assessed with a 1-RM bench press and a 1-RM Smith machine squat. Hypertrophy was measured with ultrasound imaging of the muscle thickness of the biceps, triceps, vastus lateralis, and rectus femoris.
The study concluded that training muscle groups either twice or three times per week results in similar increases in muscular strength and hypertrophy in young adult trained men when the volume is equated between the training conditions. This study was limited to statistically small sample size, short duration, and trained young adult men.
Study 3
A 2024 systematic review with meta-analysis analyzed 14 studies on the effect of split versus full-body routine (3). Three of the fourteen studies included women, and all included a broad spectrum of training status. All fourteen studies assessed 1-RM strength with bench press or similar lower body exercises and muscle hypertrophy testing such as ultrasound, DXA, and bioelectrical impedance.
The study found strong evidence that utilizing split or full-body routines provides similar strength gains and muscle hypertrophy when volume is equated. They recommend that the training split style be selected based on personal preferences and goals outside of strength and hypertrophy.
Which Is Better?
Research comparing different training splits for strength and hypertrophy shows that full-body and split routines yield similar results when training volume is equated. Though these studies did not compare every possible training split, they captured most because most splits can be categorized as either whole body or splitting up the muscles into separate days. When choosing one for you, pick based on the time you have available to train, your experience level, and consider your other goals you’re trying to achieve.
References
- Evangelista AL, Braz TV, La Scala Teixeira CV, Rica RL, Alonso AC, Barbosa WA, Reis VM, Baker JS, Schoenfeld BJ, Bocalini DS, Greve JMD. Split or full-body workout routine: which is best to increase muscle strength and hypertrophy? Einstein (Sao Paulo). 2021 Aug 30;19:eAO5781. doi: 10.31744/einstein_journal/2021AO5781. PMID: 34468591; PMCID: PMC8372753.
- Lasevicius T, Schoenfeld BJ, Grgic J, Laurentino G, Tavares LD, Tricoli V. Similar Muscular Adaptations in Resistance Training Performed Two Versus Three Days Per Week. J Hum Kinet. 2019 Aug 21;68:135-143. doi: 10.2478/hukin-2019-0062. PMID: 31531139; PMCID: PMC6724585.
- Ramos-Campo, Domingo J.1; Benito-Peinado, Pedro J.1; Andreu-Caravaca, Luis 2,3; Rojo-Tirado, Miguel A.1; Rubio-Arias, Jacobo Á.4. Efficacy of Split Versus Full-Body Resistance Training on Strength and Muscle Growth: A Systematic Review With Meta-Analysis. Journal of Strength and Conditioning Research 38(7):p 1330-1340, July 2024. | DOI: 10.1519/JSC.0000000000004774
