What the research says

6 ways to get strong. Compared.

For maximal strength, weights are the reference in the research. Unstable surfaces like the BOSU and the Swiss ball cost force, TRX holds up for beginners, and Pilates builds control rather than strength. Logic Workout works differently: at the right level, 5 reps on the Logic ball take dozens of muscles near failure at once.

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A man and a woman in a side plank, each on a Logic ball

First, the rule

Muscle grows from effort near failure.

Not from the weight, and not from wobbling: if you can do lots of reps, you never get there. Two questions for every method.

  1. How many muscles get close to failure?

    A few prime movers, or dozens of muscles at once, stabilizers included?

  2. How many reps until failure?

    5, or as many as you like? If you can keep going, you never get near failure.

Method by method

What the research says. What we found.

Each method with the research on it for strength, and how it differs from Logic Workout. The research is cited as published; what we found ourselves is marked as ours.

Reactive demand, Pilates = 1×
  1. Weights 3×
  2. TRX 5×
  3. Pilates 1×
  4. BOSU 8×
  5. Swiss ball 8×
  6. Logic Workout 50×

Our measurements: wrist accelerometry (Apple Watch), jerk and Welch power spectral density, 3 axes, 2 to 12 Hz. Reactive demand is our proxy for how many muscle fibers have to work, not a count of them. The Swiss ball value is an estimate, about the same as the BOSU.

#1 · Weights

The reference for max strength.

What the research says

Heavy, stable, predictable. Ground-based free weights are what sports science recommends to build strength in athletes.

Canadian Society for Exercise Physiology, position stand (Behm et al., 2010)

The difference with Logic

A heavy set takes you near failure in 5 reps, but only in a few prime movers. On the Logic ball, at the right level, 5 reps is just as hard, and the stabilizers work near failure too: dozens of muscles at once, at low load. Yes, this is strength training. 2h of Logic beats 6h of weights.

17× the reactive demand on the Logic ball

#2 · TRX

Fine for beginners. Much worse for advanced.

What the research says

In older adults, 12 weeks of suspension training built about as much strength as weights. In trained athletes, studies on unstable training like TRX show much smaller gains than weights. We found no TRX trial in advanced lifters.

Randomized trial, Eur J Appl Physiol, 2020 · Cressey et al., J Strength Cond Res, 2007 · Behm et al., Sports Medicine, 2015

What we found

For advanced lifters it falls far behind weights: the load tops out at your bodyweight, and the anchor carries part of the job. The Logic ball has no anchor and no fixed pivot: it moves under you in every direction, about ten times a second.

10× the reactive demand on the Logic ball

#3 · Pilates

Great for control. Not for strength.

What the research says

Strong evidence for flexibility and dynamic balance, moderate for muscular endurance. Strength gains: not established.

Cruz-Ferreira et al., Archives of Physical Medicine and Rehabilitation, 2011 (systematic review, 16 studies)

The difference with Logic

It looks like Pilates. It's almost the opposite. Pilates is slow, controlled and predictable. Logic is fast and reactive, and it builds the strength. You keep the control.

50× the reactive demand on the Logic ball

#4 · BOSU

A wobble that steals force.

What the research says

Trained athletes who trained on unstable surfaces gained less power and speed than with the same training on solid ground. A meta-analysis of 22 studies does not recommend unstable surfaces for young, healthy athletes who want to perform on stable ground.

Cressey et al., J Strength Cond Res, 2007 · Behm et al., Sports Medicine, 2015

The difference with Logic

A BOSU only tilts slowly and deforms mildly, so the body learns it fast. There is no Reactive Falling Effect. The Logic ball rolls, deforms and springs back at once, too fast to plan.

6× the reactive demand on the Logic ball

#5 · Swiss ball

Too big. Too slow.

What the research says

A chest press on a Swiss ball produces about 60% less force than on a bench. The muscles steady you instead of pushing.

Anderson & Behm, J Strength Cond Res, 2004

What we measured

A Swiss ball moves you less than once a second. The Logic ball is 18 to 22 cm and moves you about ten times a second. Even a 30 cm ball gives 30 to 40% less reactive demand.

~6× the reactive demand on the Logic ball

#6 · Logic Workout

5 reps near failure. Every muscle.

What we found

Gym-goers and athletes who switched to Logic, or swapped 2 hours of their training for it, all added at least 15% to their PR lifts in one month, in weight or in reps. Olympic athletes included. Established with 1000+ people over 10 years. A first study confirmed it.

First study: Sornette & Sornette, 2025. Open-access preprint on arXiv (2506.13959), peer review pending.

What's next

A new study with a university, built for full peer review: independent confirmation, and exactly how it works. To take part or support it, contact us.

A wobble steals force. The fall is the load.

Common questions

How does Logic Workout compare with weight training?

Weights are the reference for max strength, but a heavy set takes only a few prime movers near failure. On the Logic ball, at the right level, 5 reps is just as hard, with the stabilizers near failure too: 17 times the reactive demand of weight training in our measurements. Yes, this is strength training. 2h of Logic beats 6h of weights.

Is TRX good for building strength?

For beginners and older adults, yes: in a 12-week randomized trial, suspension training built about as much strength as weights. In trained athletes, studies on unstable training like TRX show much smaller gains than weights. What we found: advanced lifters fall far behind, because the load tops out at bodyweight.

Does Pilates build strength?

The research supports Pilates for flexibility, dynamic balance and muscular endurance; strength gains are not established (a systematic review of 16 studies, 2011). Logic Workout can look similar, but it is almost the opposite: fast and reactive, with 50 times the reactive demand of Pilates in our measurements.

Is BOSU training good for strength?

A BOSU is a good balance and rehab tool. For strength, trained athletes who trained on unstable surfaces gained less power and speed than on solid ground. A BOSU tilts slowly and the body learns it fast. The Logic ball rolls, deforms and springs back about ten times a second.

Why is the Logic ball so small?

Size sets the speed. A Swiss ball moves you less than once a second, slow enough for the body to plan. The Logic ball is 18 to 22 cm and moves you about ten times a second, close to human reaction time. Even a 30 cm ball gives 30 to 40% less reactive demand.

Isn't Logic Workout just instability training?

No. Instability training puts a wobble under a lift, and the wobble steals force from the lift. The studies agree it loses to weights, and so do we. Logic Workout is built around the fall itself: catching it is the load. The proof is on stable ground: PR lifts go up at least 15% in one month.

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Don't believe the science? Try it yourself.

Note your max today. Swap 2 hours a week for Logic. Check it in a month.

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A strength test in the Logic Workout app: the body map, then each target marked Pass or Aced