Stop blowing up at lap 6.
rox-strat is a hyrox pacing app for iPhone and Apple Watch. Punch in your 5K time and your station PRs. Get a plan for race day — every run, every station, every Roxzone transition. On race day, the Watch tells you live if you're ahead or behind.
Built by an athlete who's been burned by the lap-6 wall, for athletes who want to stop being.
A short note
"I trained for 14 weeks. Hit my 5K target. Showed up on race day, went out way too hard on lap 1, and by Sled Pull lap 5 my legs were gone. I finished, but it was ugly. That's why this app exists."
Most pacing tools are calculators that hand you a single finish time. They don't model the chain reaction — how cooking a run inflates the next station, how Wall Balls at lap 8 isn't the same workout as Wall Balls at lap 1. rox-strat does. It uses the same formula your coach uses (Riegel, 1981), layered with on-device ML that learns your station decay curve. Free for the basics. Paid for the rest.
What it does
3 focus areas.
Not a Swiss-army knife. A pacing engine, a readiness check, and a transition coach.
Step 01 · before race day
Build a plan from your numbers.
Punch in your 5K time and 8 station PRs. Pick how hard you want to go — Conservative, Target, or All-Out. Get a lap-by-lap plan: 8 runs × 1km, 8 stations, 8 Roxzone transitions. 24 segments, every one with a target time.
- Riegel-formula 1km pace from your 5K
- Fatigue penalties that scale lap-by-lap
- Switch aggression — finish time updates live
Step 02 · the morning of
Read your readiness before the gun.
rox-strat pulls HRV and sleep from Apple Health on race morning. If your readiness is down, the app suggests holding back. If you're peaked, it'll let you push. No more 'I felt great at the warm-up' lies you tell yourself.
- HealthKit HRV + sleep, on-device
- Readiness suggests pace adjustments
- Strava feeds your weekly run volume (Pro)
Step 03 · the Roxzone
Don't lose the race in transition.
The transition area is where most athletes leak 60-120 seconds without realizing it. rox-strat has a Roxzone guide with target times per zone, drill timers you can run mid-warm-up, and a technique library for every station.
- Target transition times: 60s / 75s / 90s by aggression
- Pre-race drill timer (rack-before-entering, etc.)
- Technique library for all 8 stations
On race day
A live ghost on your wrist.
The Apple Watch app shows you one number that matters: how far ahead or behind plan you are, right now. Tap to log a split. The plan rebalances forward in real time. No reaching for your phone mid-race.
- Latency
- <100ms
- Segments
- 24
- Network
- none
Plan syncs from iPhone before the gun. The Watch persists it locally and keeps running if your phone runs out of battery or walks out of Bluetooth range. Splits sync back when you reconnect.
Pricing
Free is enough. Pro is more.
The pacing simulator and the Watch ghost are free forever. No ads. No paywalls in the middle of race day.
Free
$0
Everything you need for race day.
- Lap-by-lap race simulator
- Apple Watch live race ghost
- Roxzone transition guide
- Personal Fitness Test (PFT)
- iCloud sync across devices
Pro
For athletes who care about every split. Cancel anytime in App Store settings.
- ML decay engine (on-device CoreML)
- Live readiness score (HRV + sleep)
- Strava sync — auto weekly run volume
- Fatigue sliders — tune the curve
- CrossFit converter (1RM / Fran → station PRs)
- + Everything in Free.
Honest disclosure
About your data.
rox-strat doesn't have a server. The pacing math runs on your phone. The ML decay models are bundled with the app and run on-device through CoreML. Your training data, HRV, sleep — none of it leaves your device unless you explicitly export it.
Sync between your iPhone and Apple Watch goes through Apple's iCloud, in your private CloudKit container. There is no rox-strat database, no rox-strat account you sign up for, and no marketing pixel watching what you tap.
Apple's App Store privacy nutrition label for the app reads: Purchase History · linked to your identity · not used for tracking. That's it. That's the whole label.
FAQ
Things people ask.
Do I need an Apple Watch?
+
No. The iPhone app is fully usable on its own — simulate the race, lock in your plan, run it manually. The Watch ghost is an upgrade for people who want hands-free pacing on race day.
What's the PFT — do I have to do it?
+
It's an optional 6-stage Personal Fitness Test that captures your 5K time and station PRs in one session. You can also skip it and enter your numbers manually if you already know them.
How does the pacing math actually work?
+
The Riegel formula (1981) predicts your 1km pace from your 5K PB. Then fatigue penalties scale by lap: 0% on laps 1-2, 5-10% on laps 3-5, 15-25% on laps 6-8. Wall Balls late in an all-out race can hit +35%. Pro tier swaps in three CoreML models that learn from your real station data, not just the formula.
Is this affiliated with HYROX®?
+
No. rox-strat is independent. HYROX® is a registered trademark of Hyrox World GmbH. We reference the format and station names descriptively because that's the sport you're training for.
Why "rox-strat"?
+
Race strategy for the rox format. Lowercase wordmark because we don't shout.
Will there be an Android version?
+
Not for now. The app leans hard on Apple Watch + HealthKit + CoreML. If enough Android athletes ask, we'll revisit — but it'd be a six-month build.
What does the free trial look like?
+
New subscribers get 3 months of Pro for free before any charge. Apple handles the billing — you can cancel from Settings → your Apple ID → Subscriptions any time before the trial ends and you won't be charged.
Does the app work offline?
+
Yes, end-to-end. The pacing math runs locally on your phone, the ML decay engine is bundled with the app, and the Watch persists your plan in local storage. The only thing that needs internet is the optional Strava sync (Pro).
Race the version of you that showed up today.
Not the PR fantasy. Not the warm-up high. The athlete who actually steps to the line.
Not affiliated with HYROX® or Hyrox World GmbH.