The science behind your splits
Data analytics and mathematical models applied to endurance performance — to turn your training into a concrete race plan.
The model
HeyMasterPaceLab combines three signals — your run threshold pace, cycling FTP, and swim CSS — with race-specific intensity targets to produce realistic, discipline-aware pacing.
Race intensities
- Marathon: ~94% of threshold pace, 85–92% LTHR
- Olympic triathlon bike: ~85% FTP · run: ~95% threshold
- Half Ironman bike: 75–80% FTP · run: ~91% threshold (with fatigue)
- Ironman bike: 65–72% FTP · run: ~85% threshold (strong fatigue penalty)
Fatigue model
For triathlons, run pace is decayed by accumulated swim+bike duration: roughly +2.2% slower per hour of prior racing, capped at 12%. This matches empirical run pace dropoff across age-group athletes at 70.3 and 140.6 distances.
Connecting your devices
Direct Garmin connection isn't live yet, but it's coming soon. In the meantime, by connecting Strava you already have full control of all your data: Strava is synced with Garmin, Wahoo, Polar, Apple Fitness and TrainingPeaks and automatically collects every activity for you.
HeyMasterPaceLab handles the rest: it analyses your history in real time with the best mathematical model ever applied to endurance pacing, returning race predictions, hydration and splits tailored to you.
Roadmap
- Garmin OAuth + automatic activity sync (coming soon)
- FIT / GPX file upload
- Course elevation profile and pacing per segment
- PDF race-day plan export