Muscle recruitment to failure
Build strength faster than the gym.
Logic Workout recruits your muscles to near-maximal relative mechanical tension — induced by rolling, chaotic deformation and spring forces — loading them near their own limit, all at once.
All you need is the Logic ball and the app to follow the method.
Free for 14 days
The equipment
The Logic ball
Two 20–22 cm balls (8–8.7 in), non-slip, rated to 200 kg (440 lb), with a carrying bag. The rolling, deformation and spring rebound the method depends on come from the ball itself — small enough that corrections have to be fast, deformable enough that the surface never repeats.
How it works
Strength and muscle without heavy weights?
Heavy lifting concentrates high tension in a few prime movers along a predictable path. Logic distributes near-maximal relative tension across the whole chain at once — including the deep stabilizers a barbell never reaches. In the cohort behind our first preprint, practitioners reported strength gains and broken plateaus on two hours a week.
Read the science
Two open-access preprints on arXiv and independent press coverage. Peer review is pending on both papers — read them and judge for yourself.
Preprint
Harnessing the Reactive Falling Effect for rehabilitation and performance boosting
The cohort work behind the method, covering performance and recovery.
Sornette & Sornette, 2025. Open-access preprint on arXiv (2506.13959), peer review pending.
Preprint
Case study of a 75-year-old woman with Parkinson's disease
A single-case rehabilitation trajectory with Logic Workout training.
Sornette & Sornette, 2025. Open-access preprint on arXiv (2510.23093), peer review pending. A single case, not a controlled trial.
Press
Nature doesn't optimize for comfort — how instability makes you resilient
The method in the Swiss monthly.
Schweizer Monat, independent press coverage.
New in the app: strength tests
Find where you stand. Muscle by muscle.
Test yourself against the NFL Combine events, the Army Fitness Test, gym lifts and sprints — or against Logic Workout's own standards. Every result lands on one ladder and colours a body map, so the weak link has nowhere to hide. Then the app points you to the workouts that close the gap.
- Injury Risk
- Healthy
- Strong
- Athlete
- Legend
Pick your test
Our claim, on your numbers
The Logic Carryover
What bodyweight training should buy you: gym and track goals after 12 months of Logic Workout.
Men
NFL Combine
The six Combine events, in the official order.
Women and men
Army Fitness Test
Four events, on the Army's own scales.
On Logic Workout exercises
The Logic Standard & The Logic Athlete
Every movement at its Strong level. Then at its Athlete level.
Recovery
Out of chronic pain, back to strength
Logic began in rehabilitation. In the recovery cohort of our first preprint, participants rebuilt after injury and years of chronic pain with short, low-load reactive sessions — and reported their pain resolved and strength and function regained. The same stimulus that drives performance lets a body rebuild without heavy loading.
The app
Every session, measured
Apple Watch integration gives you a real-time Logic Effort Score, so you can see the effort a session actually demanded rather than guessing from how it felt. Stability and consistency are tracked alongside it, and every workout is logged against a weekly goal.
In the app
Warm-ups, prep, and a session for the time you have
Activity preparation workouts for what you are about to do, whether that is skiing, climbing, running or a heavy lift. Three-minute blocks when time is short, full-body sessions when it is not, and a progressive library that keeps scaling — the limiter shifts from balance to the prime movers as you get better, so the same exercise keeps working.
English and French.
Free for 14 days
Athletes using Logic Workout
Training less, they report better results than years of their old programs.
Olympic fencing
Nathalie Moellhausen
Cut her training from 10 hours a week to 3 and reported better performance — faster recovery, more time on fencing skill.
Athlete-reported.
Strength & mass
Soop
His physique fronted the Expendables poster. He added Logic Workout to push his strength and mass further — without ever touching a weight.
Weightlifting
David
Added 25 pounds to his squat after years of plateau, on one hour of Logic a week.
User-reported result.
The mechanism
The Reactive Falling Effect
The ball produces three forces at once — rolling, chaotic deformation, and a spring rebound — so your nervous system can never pre-load a motor pattern. Because the balls are small, corrections have to be fast, which puts the demand in a 2–12 Hz band that stable training never reaches.
Accelerometry shows roughly ten times the jerk of a stable, maximally braced push-up. That measures the demand the movement imposes, not the muscle's response. EMG studies are underway to test recruitment directly, with a protocol designed to disprove it if it is wrong.
Method: Apple Watch wrist accelerometer, 2–12 Hz band, jerk and spectral power, against a stable push-up matched for voluntary tension. A demand characterisation, not a recruitment measurement.
Common questions
Isn't this just instability training?
No. Instability training tries to improve your balance. Logic uses unpredictability to make your nervous system recruit more muscle, harder. Different goal, different mechanism, different result.
Is this Pilates with a ball?
The ball might look the same — it is not. The Logic ball is smaller, with deformation and spring properties engineered so corrections land in the fast 2–12 Hz band a Pilates ball never reaches. And the mechanism is opposite: Pilates is slow, controlled, predictable — it trains form. Logic is fast, reactive, unpredictable — it builds the strength and muscle form is supposed to carry.
How much time does the program take?
From ten minutes a day to four hours a week, depending on your goal. The method's creator advocates two hours a week — four sessions of 30 minutes — for an athlete-level body.
Will it replace heavy lifting?
Unless you are a bodybuilder chasing hypertrophy in one specific muscle, or competing in a lift where an exact movement under load is the event — yes. This is where the science is incredible: the Reactive Falling Effect drives muscle fibres across the whole body close to maximal tension. Weightlifters report building more muscle and more strength after switching to Logic Workout.
For transparency, the exact phenomenon is under study: we know the result, and the research now running is about understanding exactly how a bodyweight exercise can outperform a loaded one.
The other Logic apps
Same method, applied to sleep and to breath.
