Fresh sets count more
The model gives later sets in one workout progressively less value. Splitting the same weekly sets across sessions can therefore raise the modeled total.
Free hypertrophy tool
Weekly Net Stimulus Calculator
Compare how often you train a muscle and how many effective sets you perform each session. The calculator estimates stimulus with diminishing returns, subtracts modeled signal decay, and shows which schedule produces the stronger weekly result.
Use this as a comparison model. The score is in arbitrary units and cannot predict your actual muscle growth.
Model assumptions
Enter 1 to 6 sets.
Enter a duration from 12 to 72 hours.
Comparison-
Enter two schedules to compare them.
How to use the result
What the score tells you
Weekly net stimulus is most useful for comparing two plausible versions of the same program. Keep the target muscle and set quality consistent, then change frequency or per-session volume.
Long gaps carry a cost
After the selected stimulus window ends, the model applies a gradual decay cost until the next evenly spaced session.
Reality still decides
A higher score only helps if the schedule is sustainable and your loads, reps, technique, joints, and recovery remain stable.
The calculation, transparently
This implementation exposes its assumptions so the result can be interpreted as a model—not mistaken for a measurement.
- Session stimulus: effective sets are converted into stimulus units using the selected diminishing-returns curve.
- Weekly stimulus: session stimulus is multiplied by sessions per week.
- Covered time: frequency is multiplied by stimulus duration, capped at 168 hours.
- Decay cost: uncovered weekly hours are charged at a rate calibrated so the selected maintenance volume at one weekly session produces a net score of zero.
- Weekly net stimulus: weekly stimulus minus modeled decay cost.
Important: arbitrary stimulus units only support comparisons inside this calculator. A score of 4 does not mean twice the growth of a score of 2.
Example: same 12 weekly sets
The default comparison holds weekly volume constant while distributing it differently.
6 sets, twice weekly
Twelve total sets with more work concentrated in each session. Later sets encounter stronger modeled diminishing returns.
Program A4 sets, three times weekly
The same twelve sets spread across more exposures. This usually raises the model score by refreshing the session stimulus more often.
Program BLimits of a WNS calculator
The score deliberately leaves out variables that cannot be estimated reliably from three inputs.
- It does not measure exercise-specific fatigue, muscle damage, joint stress, sleep, nutrition, or training age.
- It assumes sessions are evenly distributed through the week.
- It assumes each entered set has comparable quality and directly targets the same muscle.
- It should not be used to justify a frequency you cannot recover from or perform consistently.
- Scientific studies inform the curve anchors, but the combined weekly score remains a theoretical programming model.
Research and model basis
The calculator is inspired by Chris Beardsley’s Weekly Net Stimulus framework and uses published dose-response and maintenance findings as visible anchors. Methodology updated July 16, 2026.
VolumeLogic model equation: weekly net stimulus = frequency × curve(effective sets per session) − uncovered weekly hours × calibrated decay rate. The cited studies inform curve anchors and maintenance assumptions; they do not directly validate this combined equation or its score as a growth prediction.
- Schoenfeld, Ogborn & Krieger (2017): meta-analysis of weekly resistance-training set volume and muscle hypertrophy.
- Pelland et al.: dose-response analysis used for the less-steep diminishing-returns curve assumption.
- Bickel, Cross & Bamman (2011): reduced training-dose research informing the maintenance-volume assumption.
Related tools
Use net stimulus to compare distribution, then check total sets and track what happens in your real training.
Weekly net stimulus FAQ
How to interpret the score without asking more of the model than it can answer.
What is weekly net stimulus?
It is a theoretical comparison of training stimulus created during the week and the modeled loss of that signal between sessions. It is expressed in arbitrary units, not grams of muscle or a predicted growth percentage.
Is a higher weekly net stimulus always better?
No. The score does not include joint stress, systemic fatigue, exercise quality, adherence, or your individual recovery. Prefer the higher-scoring schedule only when both options are realistic and your performance supports it.
What counts as an effective set?
Enter challenging working sets that directly train the muscle and finish reasonably close to failure. Exclude warm-ups and easy technique work. Keep your definition consistent across both programs.
Why does frequency change the result?
The model assumes the first effective sets of a session contribute more than later ones and that the training signal eventually decays. More evenly spaced exposures can reduce both per-session diminishing returns and time without a modeled signal.