TRAINING PRINCIPLES
Training frequency
How often you get to the gym and how often you train a given muscle are two different questions. The second one drives the design.
The short answer
Tailrep's programs hit each muscle about twice a week. Not because less won't work, but because it's the easiest way to distribute the volume you've decided on.
What the research shows
- Schoenfeld et al. (2016) found that, with volume equated, training a muscle twice a week beat once a week for hypertrophy (effect size 0.49 vs 0.30). Whether three times beats twice remains undetermined.
- The same authors' 2019 meta-analysis concluded that frequency does not meaningfully affect hypertrophy once volume is equated. Frequency may be working as a way to distribute volume rather than as a driver itself.
- Pelland et al. (2026) likewise found frequency's independent effect on hypertrophy compatible with negligible. For strength, though, the probability that gains rise with frequency was 100%.
- Grgic et al. (2018) also found higher frequency favorable for strength. Size and strength responding differently is what makes this variable awkward.
How to apply it
- Decide how many days a week you can realistically train first. Treat frequency as the means of distributing your volume
- Two or three days: full body. Four: upper/lower. Five or six: push/pull/legs. All of them land each muscle about twice a week
- Splits where missing one day drops an entire muscle for the week are harder to finish when your schedule slips — pick one that matches the days you can actually train
Programs built on this principle
- Full Body (2 Days a Week)2x a week · Beginner
- Full Body (3 Days a Week)3x a week · Beginner
- Upper/Lower Split (4 Days a Week)4x a week · Intermediate
- Body-Part Split (5 Days a Week)5x a week · Advanced
- Upper/Lower + Push/Pull/Legs (5 Days)5x a week · Advanced
- Push/Pull/Legs (6 Days a Week)6x a week · Advanced
References
Limits of this evidence, Whether three or more sessions per muscle beats two isn't clear. Note also that the conclusion flips depending on whether volume is equated.
Schoenfeld BJ, et al. (2016) Sports Medicine
Effects of Resistance Training Frequency on Measures of Muscle Hypertrophy: A Systematic Review and Meta-Analysis
Schoenfeld BJ, et al. (2019) Journal of Sports Sciences
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
Grgic J, et al. (2018) Sports Medicine
Effect of Resistance Training Frequency on Gains in Muscular Strength: A Systematic Review and Meta-Analysis
Pelland JC, et al. (2026) Sports Medicine
The Resistance Training Dose Response: Meta-Regressions Exploring the Effects of Weekly Volume and Frequency on Muscle Hypertrophy and Strength Gains
Lasevicius T, et al. (2019) Journal of Human Kinetics
Similar Muscular Adaptations in Resistance Training Performed Two Versus Three Days Per Week
Bartolomei S, et al. (2021) Journal of Strength and Conditioning Research
A Comparison Between Total Body and Split Routine Resistance Training Programs in Trained Men