I spent the first three years of serious lifting doing 5 chest exercises on Monday and 2 rear delt sets on Friday when I remembered. My app said I was crushing it. 80+ sets a week. Great consistency streak.
My front delts were overdeveloped. My rear delts didn't exist. My chest was fine but my side delts had stalled for over a year. I had no idea because my app only showed one number: total sets.
That number is useless for hypertrophy. Here's why.
Total sets is a vanity metric
Your workout app shows you "82 sets this week" like that means something. It doesn't. Not for muscle growth.
Two lifters both do 80 sets this week. Lifter A does 20 sets of chest, 16 of quads, zero side delts, zero rear delts. Lifter B distributes 6-10 sets across every major muscle group. Same total. Completely different outcomes in 12 weeks.
Lifter A has a lagging upper back, non-existent side delts, and no idea why. Lifter B is growing proportionally because every muscle group is getting enough stimulus.
Their apps show the same number. Their mirrors won't.
Total sets is a measure of effort. It's not a measure of quality. And for hypertrophy, the distribution of your sets matters more than the sum.
Every muscle has its own volume target
This is the part most lifters understand conceptually but don't act on.
Your chest might grow best at 12-16 sets per week. Your side delts might need 16-20. Your quads might start breaking down past 12. These numbers are different for every muscle group, and they're different for every person.
The research calls these ranges volume landmarks — MV, MEV, MAV, MRV. You don't need to memorize acronyms. The point is simpler: each muscle group has a zone where growth happens, and you need to be in that zone. Not above it. Not below it.
When you're only tracking total sets, you can't see this. You don't know that your chest is at 18 sets (probably past your MRV) while your rear delts are at 4 (below your MEV). You just see "80 sets" and think the week went well.
The compound problem
Bench press trains chest, front delts, and triceps. Barbell rows hit lats, rear delts, biceps, traps. So which muscle group gets credit for the set?
The standard approach is primary muscle group attribution. Bench = chest. Rows = lats. Lateral raises = side delts. You count the set toward the muscle doing the most work.
Is this perfect? No. Compounds do contribute to secondary muscles. But it's consistent, it's trackable, and it matches how the research counts sets when studying volume-hypertrophy relationships.
The real problem isn't which system you use. It's that most lifters don't use any system. They have no idea how many sets per week their rear delts are actually getting because they've never tallied them separately from their back work.
The spreadsheet is not the answer
Some lifters figure this out and build a spreadsheet. Export from their workout app. Manually classify each exercise to a muscle group. Tally weekly sets. Compare against their target ranges.
I tried this. It lasted about six weeks.
The problem isn't the concept — it's the maintenance. You're spending 20-30 minutes a week on data entry for something your app already has the data to calculate. It knows that bench press is a chest exercise. It knows you did 4 sets. It just doesn't bother to group them by muscle and tell you whether 14 total chest sets this week is enough.
The data is already in your app. Every set, every exercise, every date. The per-muscle breakdown should be automatic. The fact that you have to export to a spreadsheet to get this is a product gap, not a user problem.
What changes when you can actually see it
I started tracking volume per muscle group about a year ago. The first thing I noticed: my side delts were chronically under-trained. 4-6 sets a week, most weeks. Way below the growth zone.
I added 2 extra sets of lateral raises to two sessions per week. That's it. Four more sets. Within 8 weeks, my side delts started responding for the first time in over a year. The issue was never genetics or exercise selection. It was volume. I wasn't doing enough, and I couldn't see it.
The second thing I noticed: I was hammering chest past my recovery capacity almost every week. 18-20 sets. Joints felt fine, but my strength wasn't progressing and I had more soreness than I should've. Dropped to 14 sets. Performance went up. Recovery improved. More growth from less work.
Neither of these insights was available from total volume. You need the per-muscle view.
What to track and how to read it
Here's the minimum viable version of per-muscle volume tracking:
Count working sets only. A working set is roughly 5+ reps at a challenging intensity. Warmup sets don't count. Your 3 sets of empty bar bench before you load the weight? Not training stimulus. Don't count them.
Classify by primary muscle group. Each exercise counts toward one group. Bench = chest. Pull-ups = lats. Curls = biceps. Don't overthink the compounds.
Compare against a target range. For most muscle groups, 10-16 working sets per week is a reasonable growth zone to start with. Adjust based on how you respond. If growth stalls, try adding 2 sets. If recovery suffers, drop 2-4.
Check before you train, not just after. The most useful moment to see your volume data is before your session. "Side delts are at 6 sets and it's Thursday. I need to add laterals today." That's training with data instead of habit.
The bottom line
Total sets tells you how much you worked. Per-muscle-group volume tells you whether that work is distributed in a way that makes muscles grow. One is a measure of effort. The other is a measure of training quality.
If you train for hypertrophy and you're not tracking volume per muscle group, you're guessing. Maybe you're guessing well. But you could just look at the numbers.