The Best Training Splits for Muscle Growth in 2025: A Practical & Informed Guide
Introduction
If you’ve been training for more than a year or two, you’ve likely asked (or re-asked) the question: what’s the best training split for hypertrophy?
It’s an important one—and one I’ve personally revisited many times over the years. From my early days running classic bro splits, to more recent iterations of push/pull/legs, full body, and upper/lower systems, I’ve trialled nearly every configuration both on myself and with dozens of clients. And while no split is universally superior, some offer a more balanced, sustainable, and biomechanically sound path to long-term progress.
This article walks you through what I’ve found to be most effective, supported by current evidence, practical application, and biomechanical reasoning—especially insights from researchers like Chris Beardsley who’ve done a stellar job breaking down mechanical tension, recovery dynamics, and how fatigue distributes across joints and muscle groups.
Why Your Split Matters (But Isn’t Everything)
Let’s start with a simple truth: your training split isn’t the most important variable for muscle growth.
Progressive overload, effective reps, exercise execution, nutrition, and sleep still sit higher on the hierarchy. But your split can strongly influence your recovery, ability to accumulate quality volume, and injury risk over time. In short: it’s the container that holds your training.
The Case for Upper/Lower Splits
Out of every structure I’ve returned to across the years, a 4-day upper/lower split remains the most repeatable and effective for general hypertrophy.
Key reasons:
Fatigue management: By grouping similar movement patterns (horizontal push/pull, vertical push/pull, etc.) into the same day, you reduce redundant shoulder/elbow loading spread across the week.
Optimal frequency: Hitting each muscle group ~2×/week aligns with findings from Beardsley’s synthesis of hypertrophy research, showing that training a muscle every 48–72 hours likely captures most of the muscle-building stimulus without excessive interference.
Volume regulation: With more muscles to train per session, you’re less likely to overshoot volume and more likely to prioritise compound lifts and train with real intent.
Sample structure:
Monday: Upper (horizontal push/pull emphasis)
Tuesday: Lower
Thursday: Upper (vertical push/pull emphasis)
Friday: Lower
You can periodise this using heavy/light days, mechanical tension/metabolic stress days, or a linear load progression with rep cycling.
Alternatives and Contextual Options
Push/Pull/Legs (PPL)
Works well for people who can train 5–6 days per week
Downsides: overlapping joint stress (especially shoulders, elbows), and can turn into volume creep if not managed well
Best suited for high-recovery trainees or those using pharmacological support
Full Body 3×/week
Ideal for beginners or busy professionals
Beardsley notes that compound lifts produce high systemic fatigue; 3 full-body sessions at high intensity can push recovery limits if not planned well
Adjust with exercise selection and rest-pause techniques if training time is limited
Bro Splits (Body Part Splits)
Common in physique culture, and not useless as once believed
But often suffer from low training frequency and excessive intra-session volume
Beardsley’s work shows that the stimulus:fatigue ratio drops off after ~5–8 hard sets per muscle per session
You’re better off distributing that volume across the week
What the Most Recent Literature Says…
While the “train each muscle 2×/week” recommendation is still grounded in 2016–2019 meta-analyses, more recent biomechanical analyses have refined the conversation:
Chris Beardsley (2021–2024): Emphasises the interaction of mechanical tension, regional hypertrophy, and fatigue distribution. Notes that too frequent indirect loading of stabilising joints (shoulder, elbow) can be a hidden limiting factor.
Grgic et al. (2021): Found no significant difference in hypertrophy between 1× and 2×/week frequency if total volume is equated, but acknowledged practicality and recovery benefits of higher frequency for most.
Hackett et al. (2022): Suggested that more frequent exposure to quality effort (e.g. 2×/week) improves motor learning and movement efficiency—especially in compound lifts.
In real-world terms? You can make 1×/week work technically if you’re very strong, very focused, and managing all other variables—but it’s likely not optimal for most.
Special Considerations for Different Trainees
Late Beginners to Intermediates (1–3 years):
Benefit most from upper/lower or PPL done 4–5×/week
Focus on movement quality, not chasing volume PRs
Advanced Lifters:
May benefit from split-periodised versions (heavy/light days or push/pull/legs hybrid with alternating emphases)
May need to limit frequency of heavy axial loading
Older Lifters / Reduced Recovery:
3×/week upper/lower + short full-body session works well
Weekend long sessions, mid-week minimalist full-body (e.g. myo-reps, rest-pause) can keep the stimulus up with less time investment
Final Thoughts
Your split should serve your goals and recovery (not dictate them).
In my experience, the upper/lower framework remains the most sustainable and productive middle ground. It avoids many of the pitfalls of joint overuse, fits easily into most people’s lives, and supports consistent progression over years, not weeks.
But that doesn’t mean other options are wrong. The best split is the one you can execute with intent, recover from consistently, and progress over time.
If you want to experiment with split structures that align with what we now understand about biomechanics and fatigue, start with upper/lower 4×/week and adjust from there. You might be surprised how far simplicity can take you.
References:
Beardsley, C. (2021–2024). Hypertrophy Guides and Monthly Research Reviews.
Grgic, J., et al. (2021). “Frequency of resistance training and muscle hypertrophy: a systematic review.” Sports Medicine.
Hackett, D. A., et al. (2022). “Muscle adaptations to resistance training: frequency, volume and periodisation strategies.” Journal of Science and Medicine in Sport.