Muscle Growth
James Swift · 24 Sept 2026 · 9 min read
If a muscle has stopped growing, do not automatically add sets. First make the evidence readable, then change the smallest variable that has a case against it.
Short answer: if muscle growth has stalled, do not start by adding more work.
Start by proving that the thing you care about has actually stopped moving.
That takes longer than diagnosing a stalled barbell lift.
Strength gives you fairly frequent performance data. Hypertrophy is less tidy. A target exercise can improve because you have become better at the exercise as well as because the muscle has grown. One bad mirror check tells you even less.
The first job is making the evidence readable.
You do not need a laboratory scan to make a useful coaching decision.
You do need more than:
"My arms look the same this week."
I would rather look across a stable block and ask:
None of those measures is perfect.
Together they give you something much better than reacting to one exercise or one photograph.
Suppose your squat improves while your goal is bigger quads.
That is encouraging.
It does not tell you exactly how much your quads grew.
Strength is specific to the task. Better technique, better coordination and practice with the movement can all improve the number on the bar.
That is why hypertrophy needs a longer run of evidence.
If the squat, split squat and leg extension are all moving while bodyweight and measurements are behaving as intended, I am much less interested in whether one photo happened to look flat.
If every target exercise is flat across a stable block and the physical measures have not moved either, now we have a much stronger signal.
This is the point where people often jump straight to:
More sets.
There is good evidence that weekly training volume and muscle growth are related.
That does not mean the answer to every stall is another five sets.
The relationship shows diminishing returns. The tenth useful set does not automatically buy the same result as the first useful set, and a set performed badly because the session has already fallen apart is not made productive by appearing in the spreadsheet.
Ask what the current dose looks like.
If the target muscle is getting very little direct work, the work is repeatable, recovery is fine and the target exercises have genuinely gone flat, adding productive volume has a reasonable case.
If the lifter is already doing a lot of hard work, performance is declining and later sets are poor, adding volume is a much weaker idea.
The question is not:
How much volume can I survive?
It is:
What is the smallest extra dose that gives me useful information?
Hypertrophy is not tied to one narrow rep range.
A set of six to ten can work.
So can ten to fifteen.
Higher-rep work can be useful too.
The research supports muscle growth across a broad range of loads when sets are sufficiently demanding, while heavier loading remains more specific to improving maximal strength.
That gives you room to choose a rep range that fits the exercise and the person.
A heavy barbell row and a leg extension do not need the same rep target simply because both are in a hypertrophy phase.
Pick a range you can perform consistently.
Then give it a progression rule you can read.
Training close enough to failure matters for hypertrophy.
That does not mean every set needs to end when the rep physically stops moving.
If the final reps turn into a different exercise, the rest of the session deteriorates and next week's performance becomes harder to compare, the extra effort may be costing more than it adds.
The useful work is hard enough to provide a stimulus and controlled enough to recover from and repeat.
That matters because your programme needs to generate evidence.
If every session is a test of how much fatigue you can create, it becomes difficult to tell whether the target muscle is actually progressing.
Hypertrophy gives you more freedom to vary exercises than a competition-lift strength phase.
That freedom gets abused.
Changing the main movement for a muscle every week means you spend a lot of time learning exercises and very little time collecting comparable performance.
Variation should have a job.
Change an exercise because:
"Instagram showed me a new one" is not much of a programming reason.
Keep useful exercises long enough to learn from them.
A muscle-gain phase and a fat-loss phase cannot be judged by the same expectations.
Energy deficits make gains in lean mass harder.
That does not mean every lift immediately gets weaker when you diet. The evidence is more nuanced than that.
It does mean that if gaining muscle is the main goal, nutrition is not background detail.
If bodyweight is supposed to rise and has been flat for months, adding more training may be solving the wrong problem.
If bodyweight is deliberately falling, expecting the same rate of muscle gain as a dedicated gaining phase is a poor baseline.
Decide what the phase is for before you judge it.
A lifter says their quads have not grown for a month.
Their bodyweight is stable.
The progress photos were taken under different lighting.
The thigh measurements were taken in slightly different places.
Squat performance improved, but the squat also became technically cleaner.
Leg extensions and split squats were both changed twice.
I would not call that a hypertrophy plateau.
The evidence is too messy.
The first change is not more sets.
It is a stable block.
Keep the main quad exercises in place long enough to compare. Record the work. Standardise the measurement if you are going to use it. Decide whether bodyweight is meant to rise, stay stable or fall.
Now change the scenario.
Bodyweight has been rising as intended.
The same target exercises have been in place for months.
Performance across several of them is flat.
Direct quad work is relatively low and the existing sets remain high quality.
Now adding some productive volume has a much stronger case.
The complaint sounded identical.
The baseline changed the decision.
The Progression Decision Loop still works for hypertrophy:
Hypertrophy asks you to be more patient about the signal.
It does not require a different philosophy.
The book this article is adapted from uses the following research for the relevant boundaries:
Keep the hypertrophy decision separate from the strength decision.
Use the muscle-growth library to review volume, effort, exercise stability and the evidence you are using before changing the block.
