The training journal
Clear guides to heart-rate zones, recovery, and the bigger picture.
Recovery & Readiness
A practical, evidence-backed guide for endurance athletes returning to training after illness or injury, with red flags, load progression, zone guidance, and decision rules for safer rebuilding.
Read story
Heart Rate Zones
Compare Garmin wrist heart rate with an electrical chest strap, understand when readings diverge, and decide which source to use for easy runs, intervals, cycling, and strength training.
Read story
Heart Rate Zones
Apple Watch uses age, resting heart rate, maximum heart rate, and health data to build five automatic zones. Learn what Apple confirms, how to inspect the numbers, and when manual zones make sense.
Read story
Heart Rate Zones
AirPods Pro 3 can track heart rate closely during steady treadmill exercise, while a chest strap remains the better reference for rapid changes, threshold tests, and precision-focused analysis.
Read story
Heart Rate Zones
AirPods Pro 3 and Apple Watch can supply multiple heart-rate streams during one workout. Apple automatically uses the highest-confidence source, improving coverage rather than simply averaging both readings.
Read story
Training Zones
Learn how to use heart-rate zones for hiking, fastpacking, and sustained climbs while accounting for steep grades, pack weight, altitude, heat, and the hidden muscular cost of descents.
Read story
Heart Rate Zones
Independent testing found low average heart-rate error from AirPods Pro 3 during treadmill exercise, but accuracy still depends on intensity, fit, movement, and the training decision you need to make.
Read story
Pace, Power & RPE
Trail pace changes with grade, footing, terrain, heat, altitude, and fatigue. Learn why heart-rate zones remain useful, where they also fail, and how to review trail runs without chasing road pace.
Read story
Heart Rate Zones
Apple Watch and chest straps can agree during steady exercise but diverge during intervals, cold weather, or noisy movement. Learn which signal to trust, how to compare devices, and when extra accuracy matters.
Read storyZone Training Log
A privacy-first training log for iOS and Android. Free to start. Yours to make personal.
