If you are like most guys tracking their workouts, your log looks something like this: Bench Press: 4 sets. Barbell Rows: 4 sets.

You log the primary mover, check the box, and move on. But according to a massive meta-analysis published by researchers like Dr. Mike Zourdos (Pelland et al., Sports Medicine), your math is fundamentally flawed.

By analyzing 67 resistance training studies tracking over 2,000 lifters, scientists found that tracking your training volume on a 1-to-1 scale ignores how our bodies actually accumulate stress and growth signals. If you want to maximize your time in the gym without hitting a wall of absolute burnout, it’s time to change how you count.

1. Enter “Fractional Counting” (The Synergist Spillover)

When you smash a heavy set of barbell rows, your back is the star of the show. But your biceps and rear delts are working hard to make that movement happen.

Historically, lifters either counted that row as a full set for biceps, or completely ignored it. The new research proves that the best way to predict muscle growth is fractional counting: giving indirect muscle work half-credit (0.5 sets).

If your chest and back day looks like this:

• Bench Press: 4 sets (Counts as 4 chest sets, 2 triceps sets)
• Barbell Rows: 4 sets (Counts as 4 back sets, 2 biceps sets)
• Incline Dumbbell Flyes: 3 sets (Counts as 3 chest sets)

Before you’ve even done a single curl or skull crusher, your arms have already logged 2 “fractional” sets each. If you blindly add another 12 sets of direct arm isolation on top of that, you might be accidentally throwing yourself into the danger zone of overtraining.

2. The Muscle Size ROI: The Curve of Diminishing Returns

More is better, right? Not exactly. The study mapped out a very clear curve showing how our muscles respond to weekly volume:

• Sets 1 to 10 (per muscle/week): This is your highest Return on Investment (ROI). These sets provide the most explosive muscle growth per unit of effort.
• Sets 11 to 18: Still effective, but each additional set costs about 40% more recovery capacity for a smaller slice of growth.
• Sets 20+: The returns drop off a cliff. You are essentially doing “garbage volume”—incurring massive fatigue and joint wear for almost zero extra muscle.

For busy guys, this is a massive win. It means hitting a solid 10 to 12 fractional sets per muscle group every week gets you roughly 80-90% of your total genetic growth potential.

3. Strength vs. Size: Two Completely Different Animals

If your goal is packing on pure muscle size, the study found that training frequency doesn’t matter as long as total weekly volume is matched. You can do your 12 sets on a single “bro split” chest day, or split them across three full-body days—the hypertrophy outcome is virtually identical. Pick whatever fits your calendar.

But if you are lifting for raw strength, the rules completely flip.

The strength curve flattens out remarkably fast. For the average person, detectable strength gains happen with just one fractional weekly set, and the benefits largely cap out around four sets. However, for experienced, well-trained lifters, that ceiling is higher (requiring 3 to 9 direct sets).

More importantly, frequency matters for strength. Spreading those heavy sets across multiple days per week builds more strength than cramming them into one session. Why? Because heavy lifting is a neurological skill. Practicing the bench press or squat more frequently sharpens your central nervous system, teaching your brain to recruit muscle fibers more efficiently.

The Takeaway: Train for size? Focus on total weekly volume and count your compound fractional sets. Train for strength? Focus on heavy weight, clean practice, and spread your lifts across the week.