Joe Friel Training Zone Calculator
Calculate training zones using Joe Friel's LTHR-based 7-zone system used by elite triathletes and cyclists.
About Joe Friel Zones
Joe Friel's zone system, outlined in his Training Bible series, uses Lactate Threshold Heart Rate (LTHR) as the anchor point. The 7-zone system provides more granularity around threshold (zones 5a, 5b, 5c) and is widely used in triathlon and cycling coaching.
Auto-Calculate from Your Data
Upload Strava, Garmin, or Intervals.icu exports to estimate your zones
Strava vs Garmin vs TrainingPeaks: Zone Differences
Different platforms calculate training zones differently. Here's what each expects:
Uses simple % of max HR. Zones are fixed percentages. Cannot customize.
Supports both %Max HR and %HRR (Heart Rate Reserve). Fully customizable zones.
Uses LTHR-based zones. Supports pace, HR, and power. Highly customizable.
Uses either method. Includes sport profiles with different zone settings.