Pieter

It is not exercise, and it may still be doing something worthwhile. Those are two separate questions and it is worth keeping them apart.

Not exercise, because exercise requires your muscles to generate force. If the motor is doing the work and you feel no effort, your muscles are being moved rather than working. Nothing adapts — no strength, no cardiovascular effect, and essentially no energy expenditure beyond sitting still.

Possibly useful anyway, because the well-documented problems with prolonged sitting are not only about a lack of exercise. Sitting motionless for hours reduces circulation in the legs, and passive movement does help with that. Devices of this type are commonly aimed at exactly that, and passive motion has a real role in some clinical settings.

So: a circulation aid rather than a training device. Which is a reasonable thing to own — it is just not what the marketing implied you were buying.

On your specific scenario, one correction worth making: the body does not supply an arbitrary deficit purely from fat.

On an effort of that length it will use a mix — fat, stored glycogen, and some protein, with the protein contribution rising as glycogen depletes and the effort continues. That is one reason very long events are hard on the body in ways that the calorie arithmetic does not capture.

The elevated appetite you get for a couple of days afterwards is also real and well described. Resting metabolic rate stays raised while the body repairs and refills stores, so the deficit continues after the ride while the intake catches up. That lag is normal and it is why eating well in the days after a long effort matters more than eating during it.

On whether variations close the gap: yes, quite well, and the ladder is worth knowing.

Feet elevated shifts more of your weight onto your hands. A modest elevation takes you from roughly two thirds of bodyweight towards three quarters and beyond; the steeper it gets, the more it becomes a shoulder press instead, which is a different exercise.

Weighted push-ups are the real answer for progression. A vest or a plate on the upper back lets you add load in small increments indefinitely, which is exactly what a barbell provides.

Ring or suspension push-ups add instability, which makes a light load feel much harder and trains the stabilisers heavily. Useful, though the limiting factor becomes control rather than strength.

With weight added, a push-up is a perfectly adequate substitute for a bench press for general strength and size. Where it cannot compete is at very heavy loads — a strong lifter presses well over their bodyweight, and hanging that much off your back is impractical.

Both, and the resolution is that the recovery advice is about optimality, not about possibility.

Recovery days are how you make the most of a given amount of training. They are not a precondition for adaptation. A body under daily load still adapts — it adapts less efficiently, with more accumulated fatigue and more injury risk, but it adapts.

So the honest framing is: basic training is not an optimal muscle-building programme and was never trying to be. Its goal is to produce recruits who can meet a standard, within a fixed number of weeks, while also achieving several other things. Whether the physical training is well designed for hypertrophy is not a question anyone is asking.

That is worth internalising generally. A lot of arguments about training methods dissolve once you ask what the method was actually optimising for.

The other half is that the body's default is not "maintain", it is "maintain what is needed" — and maintenance is expensive.

Muscle is metabolically costly to keep. Bone density costs minerals. A large heart and dense capillary networks cost energy. From the body's point of view, keeping capacity that is never used is waste, and it disposes of it.

That is why disuse is actively harmful rather than merely neutral. Bed rest produces measurable losses in bone density and muscle mass within weeks. Nothing is wearing out; the body is removing capacity it has concluded is unnecessary.

So the correct framing is that exercise is not a benefit added on top of a baseline. Being sedentary is the intervention, and its cost is the loss of what would otherwise be maintained.

The second reason is that a beginner cannot yet generate enough fatigue to justify a split.

Body-part splits exist so that an advanced lifter can do a large volume of work for one muscle group and then leave it alone for a week to recover. That is a solution to a problem you do not have — your sets are light relative to what your body will eventually handle, and you recover from them quickly.

Six days of two body parts each also means a lot of your training time goes on isolation work for small muscles, which is the least productive thing a beginner can do. Three full-body sessions of compound movements cover everything with a fraction of the exercises.

And there is a practical point: three sessions is a schedule you can protect for years. Six is a schedule that survives until the first busy week, and the most common way beginners fail is not overtraining, it is stopping.

The second gap worth mentioning is intensity.

Walking at a comfortable pace sits well below the intensity that improves cardiorespiratory fitness meaningfully in someone already accustomed to it. You get the health benefits of activity without much of a training effect on the heart and lungs.

Two cheap adjustments, neither of which requires a gym:

• Add hills or pace. A few segments of your existing walk done fast enough to make conversation difficult changes the stimulus substantially without adding time.
• Carry something. Walking with a loaded pack turns a walk into loaded exercise and does provide some of the missing resistance stimulus, particularly for the legs and trunk.

Both fit inside the habit you already have, which matters — you said sustainability is your priority, and it should be.