I built ProsoStride to get myself moving again. Not training for a marathon. Not chasing a pace. Just returning to regular walks and slow runs at an honest intensity - the kind where I could hold a conversation, where my knees stopped complaining, and where I could keep going for a year without burning out.
The method is called Niko-Niko - Japanese for “smile”. The pace at which a smile is genuine. Hiroaki Tanaka, a Japanese exercise physiologist, named it in the 1990s and used it to take his own marathon time from 4:11 to 2:38 between his thirties and his fifties. The Western world rediscovered the same idea two decades later and called it Zone 2.
The trick with Niko-Niko is not knowing about it. The trick is staying there - neither too fast (where it stops being kind to you) nor too slow (where it stops being effective). The body is bad at self-regulating to a target. Cadence - the rate at which your feet hit the ground - is the easier knob.
ProsoStride listens to your steps and gives you a quiet audio cue when you drift outside the band. That’s the whole feature. Everything else is decoration.
iPhone alone is enough
Cadence guidance runs on the iPhone - no Watch required. Pop the phone in a pocket or armband, plug in earbuds, walk out the door.
The app uses Apple’s CoreMotion pedometer to count your steps in real time. It calculates your personal cadence band from your age and (optionally) your height, using peer-reviewed research - not vibes. Walking, you’ll hover around 110 steps per minute. Slow jogging, around 175. Both numbers are starting points. Both are sliders you can override.
Pair an Apple Watch for heart-rate zones
If you have a Watch, pair it and you also get the original Niko-Niko heart-rate target - Tanaka’s formula of 138 minus half your age, with a tight band around it. The Watch reads your heart rate; the iPhone uses it for live audio cues. “Above zone.” “In zone.” “Below zone.” Configurable, mutable, yours.
An interval timer, for the days you fancy one
Clean prepare → work → rest → cooldown phases, with phase-flooded screens on iPhone and haptics on the Watch. No coach yelling.
Why cadence and not pace
Pace is what running apps usually optimise for, and pace is the wrong target for slow practice.
When you target a pace, you fight the terrain - uphills become a struggle to “keep the number down”, downhills tempt you to overstride. When you target cadence, the terrain takes care of itself. Your steps stay frequent and short; your speed self-regulates to whatever the slope demands. Your form holds together at slow speeds (which is exactly when most people’s form breaks down).
The cadence research is unusually clean:
- For walking, Tudor-Locke’s CADENCE-Adults programme maps step rate to metabolic intensity. About 110 steps per minute is the moderate-intensity threshold for adults in their 40s and 50s.
- For slow jogging, the defensible band is 170-190 steps per minute, with the sweet spot for forefoot landing at very slow speeds sitting near 180.
- Burns, Zendler & Zernicke (2019) showed that height matters - taller runners take fewer steps per minute at matched speed, by about 12 steps for every 10 cm of height. If you opt in to share your height, the app uses this.
None of these numbers are rules. They are the best evidence I could find. The app shows you the suggested range and lets you slide it where it feels right.
Learn more about the science and practice at Niko-Niko Running.
What it deliberately does not do
It does not yell at you.
It does not have a “personal record” feature. It does not congratulate you for “crushing” anything. It does not push notifications at 7am asking why you haven’t worked out yet. It does not gamify the slow-pace practice - gamification is the opposite of what Niko-Niko is for.
It also does not have a subscription. One purchase. Use it forever.
What v2.0 brought (May 2026)
- iPhone-alone cadence mode. No Watch required for the core experience.
- Personalised targets from age, optional height, and intensity preference (moderate or vigorous).
- Niko-Niko HR mode as the default (was the more complex 7-zone system before).
- Cadence Calculator in Settings - peer-reviewed math, every value override-able.
- Rewritten first-run experience - age, height, intensity, the four sliders, all on one page.
What’s next (honestly)
I have shipped what I personally needed. The next things on my list:
- Polish localisation - I’m Polish; this is overdue.
- Watch standalone mode - at the moment the iPhone is the primary device. I want a version where the Watch can run cadence solo.
- Better recovery-day detection - the app currently doesn’t know when you’re tired. It should.
- Optional Strava export for people who want it. I don’t, but I hear you.
If you have a feature request, drop me a line at hi-stride [at] prosoche.co . I read everything. I reply most things.
Privacy
All workout data goes into Apple Health, on your device. The app does not run servers. It does not collect analytics. There is no account to make.
Pricing
One-time purchase. No subscription. No in-app purchases. No ads. No “Pro tier”.
If the app gets significantly better in v3.0, perhaps I will consider a paid upgrade. Not a subscription - a subscription means I have to keep producing “value” every month or you start to resent me. Bad relationship for both of us.
Journal
- ProsoStride is here (May 2026)