Review Drift and Long-Term Trends
One heart-rate value says little. Repeated relationships between effort, pace, heart rate, and recovery are much more informative.
Use comparable runs to distinguish progress from daily noise.
Understand cardiac drift
Heart rate can rise during a steady run because of heat, dehydration, fatigue, and duration even when pace stays similar.
Compare like with like
Use similar routes, weather, duration, and effort when reviewing drift or pace-to-heart-rate changes. Context matters more than an isolated percentage.
Turn the trend into a decision
Hold training when recovery worsens, continue when the pattern is stable, and progress gradually when comparable runs become easier or faster.
Put it into practice
- Choose a steady, repeatable run for comparison.
- Compare first and second halves with conditions and perceived effort.
- Review several similar runs before changing training.
You can describe whether a change is likely fitness, environment, pacing, sensor quality, or recovery rather than reacting to one number.
No single drift percentage proves aerobic fitness or readiness. Interpret it with pace, conditions, effort, and recovery.