Choose your mountain
Pick a peak, an interval program, and how long you have — 20, 30, 45 or 60 minutes. The program decides which zones you'll be asked to hold and when.
Heart-rate game · Apple Watch
Your heart is the controller. The mountain is waiting.
Raise your heart rate to climb. Settle it to descend. Hold the target zone and you score — drift out and the mountain stops moving. Eleven real interval programs, five peaks, and a Summit Card at the end of every one.
Free to play. $3.99 once unlocks every mountain and program. No subscription, ever.
How it works
Three steps from your couch to the summit.
The only gear you need is an Apple Watch and a willingness to work for it.
Hold the zone
Your Watch reads your heart rate every few seconds. A hiker rides a band on screen: inside the band you're climbing and scoring, outside it you've stalled. That's the whole game.
Earn your Summit Card
Every climb draws your heart rate as a mountain silhouette — a card no two climbs share. Share it from your wrist the moment you finish.
Why this exists
Rings don't motivate. Games do.
A ring is a scoreboard you read afterwards. It doesn't ask anything of you while you're actually on the treadmill, and it never once tells you that right now you're 4 bpm too low.
Precision is the point
The zone isn't advice. It's the win condition.
Most fitness apps grade you when it's over. Cardio Command scores you every second you're inside the band — so the interval you were going to coast through becomes the interval you're trying to nail.
- Points accrue only while you're in zone
- Hold it and a streak multiplier builds on top
- Leave the band and scoring stops until you're back
- Time in zone is the number every badge and record is measured against
The result is a workout you can actually lose — which turns out to be the thing that makes people finish it properly.
Zone bar · in zone
too lowtarget bandtoo high
That's the actual bar, shown larger than life. The hiker is only ever green or red — in the band, or not. One glance mid-stride tells you everything, which is the only amount of reading you can do at 150 bpm.
Streaks & precision
Hold it longer. Hold it tighter.
Two things multiply your score, and they stack. How long you've held the band without a break, and how close to dead centre you're holding it.
Streak — how long
15 sec
×1.5
30 sec
×2
1 min
×3
5 min
5 MIN
10 min
10 MIN
20 min
20 MIN
30 min+
WHITE-HOT
The score multiplier maxes out at ×3 after a minute. Past that the flame keeps climbing anyway — it brightens, the band thickens behind it, and at five, ten, twenty and thirty minutes it stops being a glyph and announces the milestone out loud.
Precision — how tight
Being inside the band scores. Being within 3 bpm of dead centre scores 20% more, and the display switches from IN ZONE to PERFECT to tell you. It's the difference between completing a program and actually perfecting it — and it compounds with the streak multiplier rather than replacing it.
Audio
You shouldn't have to look at your wrist.
Cardio Command tells you where you are without asking you to raise your arm — a cue vocabulary for entering the zone, drifting out, a zone change coming in fifteen seconds, a summit, a streak milestone. Paired with haptics, so it works with headphones or without.
Cues Only
Tones and haptics, nothing underneath. The default, and the quietest option that still coaches you.
My Music
Play whatever you already listen to. Cues duck the music briefly and let it back up — the same way turn-by-turn navigation does. Transport controls are one swipe away mid-climb.
Trail Radio
Original instrumental beds written for climbing, matched to the shape of your program.
Ridgeline · piano & strings
Whiteout · pads & atmosphere
Scree · synths & beats
Cue volume is separately set to Full, Minimal, or Silent — the music setting and the cue setting don't fight each other.
The game
Cardio science. Game brain.
Every program is a real protocol with a mountain on top. The depth is the point — this isn't one workout with a skin on it.
5 mountains
11 interval programs
35 badges
Five mountains
Grouse Mountain, Mount Whitney, Kilimanjaro, K2, Everest. Target bands narrow and warning windows shorten as you go up — Everest gives you a five-bpm band and five seconds' notice.
Eleven interval programs
Norwegian 4×4, Tabata, 10-20-30, Pyramid, Tempo, Zone 2, 30/30, Fartlek, Rescue Mission, Storm Shelter, and the classic progressive ascent. Real protocols, not invented ones.
Dynamic events
Rockfall narrows your band mid-interval. Altitude Sickness drops it. Whiteout hides your heart rate entirely and asks you to navigate by feel. Thirty seconds each, forty-five for Rockfall — and they change everything.
The Summit Card
Your heart rate over the whole climb, drawn as a mountain skyline against the zones you were asked to hold. Personal records get a ribbon. No two are alike.
Thirty-five badges
Five tracks — Summit, Precision, Event, Dedication, Collector. Some reward volume; the good ones reward a single climb done exactly right, and a few are calendar-locked to one day a year.
iPhone companion
Every climb syncs over iCloud. Full history, the badge grid, 7- and 30-day accuracy trends, personal records per mountain, and high-resolution card exports. Included free.
The Summit Card
A workout worth showing someone.
Nobody screenshots a closed ring. The Summit Card exists because the thing that actually keeps people training is other people noticing — and because your heart rate, drawn as a mountain range, is genuinely nice to look at.
- Your HR trace as a ridgeline, against the zone corridor you were holding
- Ribbons for a zone PR, a stars PR, or an all-time best — like the one on the card here
- New badges get their own card treatment
- Instagram Stories, square, and 4:5 exports — plus a transparent sticker
- Share from the Watch the second you finish, or in full resolution from your phone
Getting better, measurably
Perfect one program. Then take it up a mountain.
Because the score is built on precision rather than effort, improving is legible: the same program on the same peak, held tighter than last time, is a visibly better climb. The phone app plots accuracy over 7 and 30 days so you can see the line move.
- Accuracy trend — is your time in zone actually improving?
- Personal records per mountain, per program, per duration
- Difficulty multipliers: the same precision is worth more on K2 than on Grouse
- Longest in-zone streak, lifetime elevation, best-ever climb
The mountains
Start on Grouse. Work up to Everest.
Each peak is harder than the last — tighter bands, shorter warnings, less margin. Difficulty is also worth more: a climb on Everest scores five times what the same precision earns on Grouse.
🏔️
Grouse Mountain
Beginner · ×1
Wide bands, long warnings. Where you learn to read the game. Free.
🏔️
Mount Whitney
Intermediate · ×1.5
Bands tighten. The first peak where drifting actually costs you.
🏔️
Kilimanjaro
Intermediate+ · ×2
Long sustained efforts with less tolerance. Discipline over bursts.
🏔️
K2
Advanced · ×3
Fast transitions, tight bands, eight seconds of warning before the ground shifts.
🏔️
Everest
Expert · ×5
A five-bpm band and five seconds' notice. Every program available, nothing forgiven.
Storm Shelter · calm mode
Not every mountain goes up.
Storm Shelter runs the game in reverse. Start from whatever elevated heart rate you arrive with — post-run, post-argument, post-bad-day — and bring it down. The band narrows as you go, so settling becomes the skill being scored.
- 5, 10, or 15-minute sessions
- The zone script is generated from your actual heart rate at the moment you start
- For cooldowns, wind-downs before sleep, or a rough afternoon
- Earns Calm Descent, and Storm Veteran if you complete all three lengths
Pricing
Free to play. $3.99 once for the whole range.
Not a subscription. Not a trial that expires. One purchase, tied to your Apple ID, forever.
Free
Cardio Command
$0
The whole game, on one mountain.
- Grouse Mountain, 20 and 30-minute climbs
- The Summit Expedition program
- Every core mechanic — scoring, streaks, the flame, dynamic events
- Summit Cards and sharing from the Watch
- All audio, including Trail Radio
- The full iPhone app — history, stats, trends, badge grid
Free means free. No ads, no timer, no nagging.
One-time
Cardio Command Pro
$3.99 once
Everything above, plus the rest of the range.
- All five mountains — Whitney, Kilimanjaro, K2, Everest
- All eleven interval programs — Norwegian 4×4, Tabata, Pyramid, Tempo, Zone 2, 10-20-30, 30/30, Fartlek and more
- Rescue Mission and Storm Shelter modes
- 45 and 60-minute climbs
- The badges that only exist up there
Badges are never paywalled — you earn them on the free tier the same as anywhere else. The hardest ones just happen to live on peaks and programs Pro opens up.
Real science under the mountain.
Norwegian 4×4 for VO₂ max. Tabata for anaerobic capacity. Zone 2 for mitochondrial density. Every program is a published protocol — the game wraps it, the protocol does the work.