HEART-RATE METHODS
Heart-rate reserve versus percentage of maximum heart rate
Seventy percent of maximum heart rate and seventy percent of heart-rate reserve are different calculations. The percentage needs its method attached.
Identify the reference range
A percentage-of-maximum calculation multiplies maximum heart rate by a fraction. A heart-rate-reserve calculation first subtracts resting heart rate from maximum heart rate, multiplies that range by the fraction, then adds resting heart rate back.
Neither expression measures the runner's maximum heart rate or identifies a physiological threshold by itself. Those are inputs or separate assessments. This guide explains the arithmetic and Runome's settings convention; it is not a personalized intensity recommendation.
Calculate the same percentage both ways
Use illustrative inputs of maximum heart rate 190 bpm and resting heart rate 50 bpm. The reserve is 190 − 50 = 140 bpm.
| Fraction | Percentage of maximum | Percentage of reserve, plus rest |
|---|---|---|
| 60% | 190 × 0.60 = 114 bpm | 50 + 140 × 0.60 = 134 bpm |
| 70% | 190 × 0.70 = 133 bpm | 50 + 140 × 0.70 = 148 bpm |
| 80% | 190 × 0.80 = 152 bpm | 50 + 140 × 0.80 = 162 bpm |
At the 70% point, the results differ by 15 bpm. A disagreement between two zone displays could therefore be a method difference even if they use the same maximum. Compare the formulas before assuming either display has read the sensor differently.
Check the source of each input
Record where the maximum and resting values came from and when they were last reviewed. Do not turn a generic estimate into a measured personal maximum just by saving it in a profile. A changed resting value can also move reserve-based boundaries while leaving a maximum-only calculation unchanged.
Keep rounding rules visible near a boundary. One app may use whole-number inclusive ranges while another displays a continuous boundary. A one-bpm labeling difference can come from that choice rather than from different underlying data.
Read Runome zones with their settings
Runome's checked default zone implementation uses heart-rate reserve. Custom heart-rate zones are a Club feature. Review the values and method before comparing its time-in-zone chart with another app; do not assume “70%” has one universal meaning.
The Zone 2 example carries the calculation into a labeled zone chart. The sensor guide addresses a different source of disagreement: the recorded readings themselves. Keep settings, measurements and interpretation as separate checks.