The AI endurance coach that builds your training around heart rate, power and recovery — not arbitrary pace — and adapts every week using the data your watch already collects.
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Good Morning,
Simon
Duration
50 mins
Zone 2
135–148 bpm
Purpose · Build aerobic efficiency
Coach
"Recovery has been excellent this week. Today we're extending your aerobic base before Thursday's threshold session."
Recovery
92%
Fitness
↗ Improving
Every completed workout updates your future training.
Time, heart rate, power and RPE instead of pace.
Garmin, Coros, Apple Health, Strava and Wahoo.
"Run 5×1km at 4:00/km" creates wildly different physiological stress on a fresh leg, a humid day, or week 11 of a marathon block. Most apps don't care. We do.
Kyn prescribes the stimulus — Zone 4 for 8 minutes — and lets pace be the outcome, not the instruction. The same workout adapts to today's heat, fatigue and form, the way a great coach would.
Every prescription specifies duration and intensity zone — never raw kilometres or seconds-per-km. Push it to your watch with one tap and run by feel.
Focus: Aerobic Development
60 MIN
Total Duration
15m Warm-up
HR Zone 2 (125–138 bpm)
4 × 8m Threshold
HR Zone 4 (158–166 bpm) · 2m Recovery
10m Cooldown
RPE 2–3 / Zone 1
After every workout the engine analyses duration, HR, elevation, cadence and recovery — then rewrites the coming week before you wake up.
Adaptive adjustment
"Fatigue levels are 12% above baseline. Tomorrow's Endurance session adjusted from 90m to 70m to preserve TSB balance."
Efficiency Trend
"Your Zone 2 aerobic pace has improved by 4.2% over the last 30 days. Heart rate drift decreased to 2.8% on long runs."
Heat Compensation
"Forecast 28°C tomorrow. Reducing prescribed Z3 effort by 6% and shifting the long run earlier in the day."
VO2 Max, CTL, ATL, TSB, aerobic efficiency, HR drift, threshold pace and recovery — tracked over 7, 30, 90 and 365 days.
VO2 Max
58.4 +0.2
CTL (Load)
72.1 +4.5
Eff. Factor
1.68 +2%
TSB (Form)
-12 Stable
Pull historical activity, HR, sleep and recovery data. Push structured workouts back to the device — no manual transcription.
For runners getting started
The adaptive coach
Join the waitlist and we'll answer that question — automatically, every week, until your race.