Effective Work, explained

What is Effective Work?

Effective Work (EW for short) is Stimuli’s way of putting a number on hypertrophic training: a single measure of how much growth-driving stimulus you banked in a session. Not how much weight left the floor, but how much of that work actually counts toward building muscle.

Two workouts can move the exact same total weight and earn very different Effective Work. What separates them is simple: how hard the sets were, how far you took them, and which muscles actually did the lifting. EW folds all of that into a single number you can follow, across every set, muscle, session and week.

Reading your score

There’s no universal “good” score to hit. The number is in Stimuli’s own units, not kilos or reps, and it only ever means something compared with your own history: today against your own normal, this week against your last few.

That’s also how progress shows up. When the same sessions keep earning solid Effective Work while the weights creep up, your training is genuinely moving forward.

What Stimuli weighs

A few things separate productive training from busywork. Effective Work pays attention to each of them:

How hard the set wasA set only counts in full when the weight genuinely challenges you by the end. Light or heavy, loads you can handle without the set ever getting hard bank less, however many reps you do. Bodyweight exercises count too: your own bodyweight is the load, and any weight you add stacks on top of it.

How close to failure you wentThe reps that matter most are the hard ones near the end of a set.

Which muscles did the workEvery lift you log with weight and reps is credited to the muscles that actually drive it (most to the prime mover, less to the helpers), so the work lands where it really happened.

Full range of motionComplete reps through a full range count in full. Cut-short, partial reps bank less, and they also give up the stretch credit below: most partials skip the deep, stretched part of the movement that growth comes from.

Loading the stretchSome exercises load a muscle hard while it is lengthened and stretched, like the deep bottom of a Romanian deadlift or a chest fly. Training a muscle hard in that stretched position gives it a genuine edge for growth, so Stimuli gives those stretched positions extra credit.

Diminishing returnsHammering the same muscle over and over gives less and less extra with each set, so you can’t inflate the number by piling everything onto one body part.

Why reps close to failure matter most

A lifter pushing through a final rep near failure

This is the part most people get wrong. A set you end with plenty left in the tank leaves most of its potential unused; the very same weight, taken close to your limit, banks dramatically more Effective Work. Stop a set nowhere near hard enough and it can register nothing at all.

It’s also why honest effort logging matters so much, and why “more reps” is not the same thing as “more growth.” Quality of effort beats raw quantity.

Logging effort: RIR, in half-steps

After each set you tell Stimuli how close you took it to failure using RIR, short for “reps in reserve”: simply how many more reps you could have done before failing. RIR 2 means you had about two left in the tank, and RIR 0 means you could not have managed another. You log it in half-steps, so “about a rep and a half left” is a perfectly valid answer.

If you have used RPE before, it is the same idea from the other direction. RPE, or “rate of perceived exertion,” scores a set from 1 to 10, where 10 is all-out with nothing left in the tank. The two are mirror images: RPE = 10 - RIR, so an RIR of 2 is the same as an RPE of 8. Use whichever feels natural; Stimuli understands both.

That little bit of honesty about your effort is what lets Stimuli judge how hard you really trained, and it is the single biggest thing you can do to keep your numbers meaningful.

Rough guide: leave a little more in reserve on the big, heavy lifts (failure there costs a lot of recovery and form), and push closer to failure on smaller isolation moves, where it costs you little.

Reading the muscle map

Lighter workHarder work

Effective Work isn’t one lump sum. It’s spread across your body, muscle by muscle, and on the body map each muscle is shaded from faint to bright: the brighter the orange, the more real work that muscle did that day or week. A muscle with no shading at all simply hasn’t logged meaningful work in that window: untouched, not broken.

A body map shaded by how much work each muscle did

The map makes it obvious at a glance: bright areas are getting hammered, faint areas are coasting. It’s the fastest way to catch a muscle you’ve quietly been neglecting.

Effective Work vs. total weight lifted

Plenty of apps just add up everything you lift: sets times reps times weight. The trouble is that this total rewards junk: long easy sets, half-reps and bouncy partials all push the number up without doing much for your physique.

Effective Work rewards the opposite: hard, full-range reps taken near failure on the muscles actually doing the job. That’s why it’s the number worth watching.

Training volume and Effective Work answer different questions. Volume asks: did each muscle get enough sets this week? Effective Work asks: how much did those sets actually count? Plan your week with volume, judge it with Effective Work. See the “Training Volume” guide.

When the number dips

A lower week is not always a warning. Fewer sessions, sets stopped further from failure or a deliberately easy week all pull the number down, and a planned dip is fine. Your weekly total also starts from zero each new week, so a fresh week always opens low.

What deserves attention is an unplanned slide that lasts a few weeks: that usually means effort, attendance or recovery has quietly changed.

How to use it

Reviewing training progress after a session

Don’t chase a bigger number for its own sake. Chase the right balance. Effective Work climbing on a muscle you’re trying to grow means your plan is working. A lopsided spread is your cue to rebalance.

And treat it as a guide, not a verdict. Effective Work measures the training stimulus you created, not how good the session felt or how sore you’ll be tomorrow. Read it alongside how recovered you are, and alongside each muscle’s training volume, before deciding how hard to push next time.

Scope note: cardio, timed holds (like planks) and loaded carries are logged as time or distance, so they don’t earn Effective Work or count toward your set ranges. Both numbers track muscle-building lifting only.

Stimuli

Train with intent

Stimuli scores every set with Effective Work as you log it, and shows you where it landed.

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