Your heart rate
drives the ride.
On supported HR-adaptive workouts, Zone Pedal watches heart rate and adjusts compatible smart trainer resistance when your trainer has room to respond. Short intervals and imported workouts remain power-led with HR guardrails.
Pair devices. Pick a workout. Pedal.
Pair devices
Connect your Bluetooth heart rate monitor and smart trainer. Chest strap recommended for the fastest control response. Zone Pedal talks directly to both devices on your phone.
Pick a workout
Choose from 13 built-in workouts across 5 categories. Endurance and calibration rides can be HR-adaptive; short high-intensity blocks stay power-led with HR ceilings and post-ride honesty.
Pedal
For supported steady rides, your phone estimates starting power and trims resistance as heart rate responds when the trainer has room to move.
What the first few rides do.
Begin calibration
Start with Discover Your Cardiac Response. The 20-minute ride gives Zone Pedal initial easy-effort evidence about how your heart rate follows power.
Use the early model
A steady Zone 2 ride can start from that easy-effort profile and report whether the prior profile matched the day. It does not fully calibrate every Body metric.
Add qualifying evidence
Interval and threshold workouts add the power variation needed to improve hard-effort response, recovery timing, and confidence-labeled profile trends.
Your workouts, your data, your phone.
Post-ride insights
Your cardiac profile
Set up in seconds
HR-adaptive rides stay pointed at the target.
Fixed-Power Workout
Cardiac drift and fatigue push the session away from the intended zone.
Zone Pedal
The control loop trims resistance toward the heart-rate range when the trainer has room to respond.
Zone Pedal estimates a starting resistance for supported workouts, then trims as your heart rate responds when the trainer has usable headroom.
Built to account for the natural rise in heart rate that happens as a ride progresses — even when effort stays constant.
Resistance trims in a sample replay.
This sample replay shows the control loop shape: heart rate rises toward the band, power trims down as drift appears, and live HR remains the safety signal.
Your Body, clearly.
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Builds your baseline
After 3 interval workouts, the Your Body tab starts showing your cardiac fitness trend with honest change from your own baseline.
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Estimates your aerobic threshold
Aerobic Threshold Finder estimates where your aerobic threshold sits: the heart rate above which you're working harder than you can sustain for long efforts. It does this using DFA alpha1, a method based on subtle patterns in beat-to-beat heart rate data, and requires a chest strap transmitting RR intervals. Track how it shifts as your fitness improves.
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Estimates your VO2max
As you complete qualifying interval workouts, Zone Pedal builds a picture of how your heart responds to effort and uses it to produce a confidence-labeled VO2max estimate. It shows how fit you are relative to age- and sex-adjusted norms, with reliability shown in the estimate.
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Follow your ride from the Lock Screen
Live Activity shows heart rate, target range, and power on the Lock Screen and Dynamic Island without unlocking your phone.
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Turns history into insight
After each ride, you get a clear report: target time, what model evidence was used or updated, and interval target honesty. Qualifying interval workouts build your fitness trend over time.
Read the science before you trust the claims.
The Science page documents the controller model, simulation studies, real-ride replay checks, and known limitations.
13 Workouts, 5 Categories
Calibration
- Discover Your Cardiac Response — a guided 20-minute ride that reveals how your heart responds to effort, with real-time learning messages as the system measures you
Aerobic Threshold
- Aerobic Threshold Finder — 35-minute stepped ramp that estimates your aerobic threshold from DFA alpha1 fractal analysis of RR intervals; requires a chest strap transmitting RR intervals
Endurance
- Zone 2 Base — 30 to 90 minutes of steady aerobic work with adaptive resistance trimming
- Tempo — sustained Zone 3 effort, podcast-friendly
- Recovery — easy spinning that stays safely below Zone 2
- Steady Zone — pick any zone (1–5) and duration; Zones 1–3 can run HR-held, while Zones 4–5 stay power-led with HR guardrails
Power-Led Intervals
- Sweet Spot — long effort right below your limit
- Threshold — sustained hard efforts at your limit with recovery between (2x20 or 3x15)
High Intensity
- Norwegian 4x4 — 4 x 4 min hard / 3 min easy
- Seiler 4x8 — 4 x 8 min hard / 5 min easy
- Billat 30/30 — 3 sets of 10 x 30s on / 30s off
- Rønnestad 30/15 — 3 sets of 13 x 30s on / 15s off
- Tabata — 8 x 20s max effort / 10s rest
Start with Discover Your Cardiac Response. One 20-minute session begins calibration, so later Zone 2 rides can start from your easy-effort profile instead of a generic guess.
Advanced: Import a Zwift Workout
Open a .zwo file when you already have a rider-provided workout. Zone Pedal previews the structure, lets steady sections follow HR targets where appropriate, and keeps short intervals power-led with HR ceilings and post-ride honesty.
All data stays on your device.
Zone Pedal stores your profile and ride history locally on your phone. If you enable Apple Health, completed workout summaries are written there too.
No account. No analytics. No server.
Made for riders who care what the controller is doing.
Zone Pedal is built by Mark Koivuniemi, a biomedical engineer and indoor cyclist who wanted steady trainer work to respond to physiology, not just a fixed watt target. The app is intentionally local-only, inspectable in its ride reports, and conservative about what it claims until the evidence supports more.
One purchase. Full app.
One-Time Purchase
- All 13 workouts included
- HR-guided steady rides
- No subscription and no account
$29.99 iPhone app. No recurring billing, no cloud tier, no unlock flow.
Heart rate monitor plus smart trainer.
Bluetooth HR Monitor
Standard Bluetooth heart rate monitors are the target input. A chest strap is recommended for the fastest and cleanest control response.
Most Smart Trainers
Zone Pedal can directly control FTMS-compatible smart trainers over Bluetooth for real-time resistance changes during supported rides. Heart-rate control needs your easy Zone 2 power to sit above the trainer's minimum resistance. Zone Pedal checks that headroom during rides and labels the limit instead of reporting clean controller authority when your setup is pinned at the trainer floor.
Tacx Neo and Legacy Trainers
Some Tacx trainers use FE-C over BLE, and Cycling Power Service telemetry is supported when available for tighter ride feedback.