Endurance Athlete Zone Customization for Runners & Cyclists
Scientific Foundation
LTHR from 30' Race Field Test is essential because it's typically slightly higher than metabolic LT2 HR, particularly in advanced endurance athletes. This approach respects Polarized training principles (Dr. S. Schiller) while remaining fully compatible with any training methodology, as Tempo workouts are strategically positioned around 5km race pace intensity.
Training Zone Understanding
Z1 – Active Recovery
Recovery & Regeneration: Very low intensity for physiological restoration and recovery between hard sessions
Z2 – Aerobic Base Development
Aerobic Foundation: Builds endurance capacity, mitochondrial density, and fat adaptation at conversational pace
TL – Transition Low (Gray Zone)
No Man's Land: Provides minimal training adaptations - avoid extended time in this zone for optimal endurance development
Z3 – Turbo! Tempo®
Tempo training at faster than half-marathon pace, typically around 5km race intensity (implemented as 5min, 10min, 20min sets at 5km pace)
TH – Transition High (Death Zone)
Inefficient Training Zone AVOID - provides suboptimal adaptations, minimize time in this zone for maximum training effectiveness
Z4 – Turbo! Threshold
Lactate Threshold: Implemented as shorter intervals (4-6x4min and 3-4x6min) to maximize time at threshold without excessive fatigue
Z5 – Anaerobic Capacity
Anaerobic Power: Very short, high-power efforts (≤20s) to develop neuromuscular power and anaerobic energy systems
If LTHR (30') exceeds LT2, calculations use LTHR percentage (field-based). If LTHR ≤ LT2, LT2 serves as the basis.
For FTP from 30' field test, enter 20' average power without 0.95 multiplier (calculation is automatic). Garmin FTP values are already multiplied by 0.95, so enter them directly.
Recommended Input Fields
In the calculator, enter data according to your testing protocol:
• LT1: Heart rate at first lactate threshold (aerobic threshold)
• LT2: Heart rate at second lactate threshold (anaerobic threshold)
• MEP: Heart rate at maximum fat oxidation point (ask your exercise physiologist)
• Average power from 20' field test performance
• Or Garmin FTP (as shown in Data Field Settings)
• Alternatively, power at LT2, which practically corresponds to FTP
• Z2 = comfortable jogging/cycling where you can speak without gasping (Zone 2).
• Perform 30' Z2 at relaxed pace, maintaining ability to speak comfortably without breathlessness - avoid fast tempo. Record and calculate average HR, Power and Pace (runners) from charts as viewed in Garmin Connect app.
• For Pace enter in seconds/km: e.g., 5:40 → 5×60 + 40 = 340.
- Use data from 30' field test (average HR & Power from best 20') for precise FTP, LTHR, MEP calculation and optimal training zones for EnduroMetrics Data Field.
- If laboratory testing available, enter LT1 / LT2, Power at LT2 and MEP.
- Exception: If FTP and LTHR come directly from Garmin devices, and you prefer not to use laboratory data enter them exactly as in EnduroMetrics Data Field Settings, select "without Lab Test" and use calculator only for zone calculation.