The Question Everyone Asks
Walk into any gym and you'll hear the same debates: Should you do 3 sets or 5? Is one working set enough if you go hard? Do you need to spend two hours in the gym or is 45 minutes sufficient? The answer matters because your time is limited and you want results.
Fortunately, researchers have studied this extensively. A landmark 2017 meta-analysis published in the Journal of Sports Sciences finally gave us data-driven answers about training volume and muscle growth.
What the Research Shows
The meta-analysis by Schoenfeld and colleagues examined 15 studies comparing different training volumes. The findings were clear: there's a dose-response relationship between the number of sets you perform and how much muscle you build.
Specifically, the researchers found:
- Less than 5 weekly sets per muscle: Produces measurable but modest hypertrophy
- 5-9 weekly sets per muscle: Better results than minimal volume
- 10+ weekly sets per muscle: Significantly greater muscle growth than lower volumes
The effect was statistically significant. Performing 10 or more sets per muscle group per week produced roughly 30% greater gains compared to fewer than 5 sets.
Why Volume Matters
Training volume creates the mechanical tension and metabolic stress that signals your muscles to grow. Each set provides a growth stimulus, and more stimuli (up to a point) means more adaptation.
Think of it like studying for an exam. Reviewing material once might help, but reviewing it multiple times across different sessions produces better retention. Your muscles work similarly: repeated exposure to tension across multiple sets drives the protein synthesis that builds new tissue.
The Sweet Spot for Most Lifters
Based on this research and subsequent studies, most experts now recommend:
- Beginners: 10-12 sets per muscle group per week
- Intermediate lifters: 12-18 sets per muscle group per week
- Advanced lifters: 15-20+ sets per muscle group per week
These are weekly totals, not per-session numbers. A chest workout of 4 sets of bench press and 4 sets of flyes twice per week gives you 16 weekly sets for chest.
The Law of Diminishing Returns
More is not always better. Research suggests that beyond 20 sets per muscle group per week, the additional gains become minimal while recovery demands increase substantially.
At extremely high volumes (25-30+ sets per muscle weekly), you may actually experience worse results due to accumulated fatigue, increased injury risk, and incomplete recovery between sessions.
How to Apply This
Here's how to structure your training based on this research:
1. Count your weekly sets per muscle group. Track everything that meaningfully works each muscle. A bench press counts for chest, front delts, and triceps.
2. Spread volume across multiple sessions. Training a muscle 2-3 times per week with moderate volume each session beats hammering it once with massive volume. Recovery and protein synthesis patterns support this approach.
3. Start conservative and add over time. If you're currently doing 8 sets per muscle weekly, don't jump to 20. Add 2-4 sets every few weeks and monitor recovery.
4. Prioritize lagging muscle groups. If your chest grows easily but your back lags, allocate more of your weekly volume budget to back training.
Sample Weekly Volume Distribution
For an intermediate lifter training 4 days per week:
- Chest: 14 sets (7 on push day 1, 7 on push day 2)
- Back: 16 sets (8 on pull day 1, 8 on pull day 2)
- Shoulders: 12 sets (lateral and rear delts, front gets hit on pressing)
- Quads: 12 sets across leg sessions
- Hamstrings: 10 sets across leg sessions
- Biceps: 10 sets
- Triceps: 10 sets
The Bottom Line
Training volume is one of the primary drivers of muscle growth. The research is clear: doing more work (within reason) produces more muscle. Aim for 10-20 sets per muscle group per week, spread across 2-3 sessions, and adjust based on your recovery and progress.
If you're not tracking your volume, you're guessing. And guessing rarely beats a systematic approach backed by research.
Reference
Schoenfeld BJ, Ogborn D, Krieger JW. Dose-response relationship between weekly resistance training volume and increases in muscle mass: A systematic review and meta-analysis. J Sports Sci. 2017;35(11):1073-1082. PMID: 27433992