Full body, upper/lower or push/pull/legs?

Short answer

At equal weekly volume, all common splits produce similar muscle growth. Training each muscle about twice a week is a sound default. Choose the split that fits the days you can train.

Figures

2× · per muscle per week as a default
0.49 vs 0.30 · effect size 2× vs 1× per week (2016)
2–6 · training days, depending on split

Example plans: train muscle groups one to three times a week

What the studies show

In 2016, Schoenfeld and colleagues found more growth with twice versus once weekly training. In their 2019 meta-analysis the difference disappeared when weekly volume was equal. Pelland and colleagues reached the same conclusion; higher frequency helped strength slightly.

Why twice a week

Frequency spreads volume. 16 chest sets in one session are hard to do well; two sessions of 8 are not. That is why twice a week is a practical default.

Which split fits you

2–3 days: full body. 4 days: upper/lower or anterior/posterior. 5–6 days: push/pull/legs. Anterior/posterior splits by muscle chains, for example squats, presses and biceps versus deadlifts, rows and hamstrings.

Consistency beats structure

A 6-day plan you only complete every other week delivers less than 3 reliable days. Plan around your calendar.

Sources

Effects of Resistance Training Frequency on Measures of Muscle Hypertrophy: A Systematic Review and Meta-Analysis · Schoenfeld · 2016 · Sports Medicine PubMed DOI
How many times per week should a muscle be trained to maximize muscle hypertrophy? A systematic review and meta-analysis of studies examining the effects of resistance training frequency. · Schoenfeld; Brad Jon; Grgic; Jozo; Krieger; James · 2019 · Journal of Sports Sciences PubMed DOI Study note
The Resistance Training Dose Response: Meta-Regressions Exploring the Effects of Weekly Volume and Frequency on Muscle Hypertrophy and Strength Gains · Pelland · 2026 · Sports Medicine PubMed DOI Study note
A randomized trial on the efficacy of split-body versus full-body resistance training in non-resistance trained women · Pedersen H; Fimland MS; Schoenfeld BJ; Iversen VM; Cumming KT; Jensen S; Saeterbakken AH; Andersen V · 2022 · BMC Sports Sci Med Rehabil PubMed DOI
Effects of Variations in Resistance Training Frequency on Strength Development in Well-Trained Populations and Implications for In-Season Athlete Training: A Systematic Review and Meta-analysis · Cuthbert; Matthew; Haff; G. Gregory; Arent; Shawn M; Ripley; Nicholas; McMahon; John J; Evans; Martin; Comfort; Paul · 2021 · Sports Medicine PubMed DOI

Summaries by SetCtl, not medical advice.