Heart Rate Reserve Zone

Compute Karvonen heart-rate reserve training zone boundaries.

Description

Heart-rate reserve subtracts resting from maximum rate.

Heart-rate reserve subtracts resting from maximum rate. The Karvonen arithmetic adds a selected fraction of reserve back to resting rate.^[1]

Compute Karvonen heart-rate reserve training zone boundaries.

When to use Heart Rate Reserve Zone

Use this tool to compute Karvonen heart-rate reserve training zone boundaries.

Prepare the measured movement, timing, load or preassigned score requested. Keep protocols, units, paired measurements and caller-selected thresholds consistent.

How to use Heart Rate Reserve Zone and understand its results

Prepare the measured movement, timing, load or preassigned score requested. Keep protocols, units, paired measurements and caller-selected thresholds consistent.
Enter restingBpm, maximumBpm, lowerReserveFraction, upperReserveFraction using the field table and calculation rules, then run the tool.
Read reserveBpm, lowerTargetBpm, upperTargetBpm. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
restingBpm	Resting bpm	number	Required
maximumBpm	Maximum bpm	number	Required
lowerReserveFraction	Lower reserve fraction	number	Required
upperReserveFraction	Upper reserve fraction	number	Required

Enter nonnegative resting bpm, greater maximum and ordered fractions in [0,1]. Return reserve and both target boundaries.

target=resting+(maximum−resting)fraction

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
reserveBpm	Reserve bpm	number
lowerTargetBpm	Lower target bpm	number
upperTargetBpm	Upper target bpm	number

json

{
  "input": {
    "restingBpm": 60,
    "maximumBpm": 180,
    "lowerReserveFraction": 0.5,
    "upperReserveFraction": 0.7
  },
  "output": {
    "reserveBpm": 120,
    "lowerTargetBpm": 120,
    "upperTargetBpm": 144
  }
}

Limitations and assumptions

No maximum-rate estimation, medical suitability or personalized intensity recommendation is provided.

Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Talk Test Intensity Screen: Classify self-reported talk-test effort without claiming measured ventilatory thresholds. For a complementary task, use MET Intensity Bands: Classify MET intensity using caller-selected light/moderate/vigorous boundaries.

References

Heart Rate Reserve Zone — tool.io

Similar or alternative tools

Talk Test Intensity Screen
Classify self-reported talk-test effort without claiming measured ventilatory thresholds.
MET Intensity Bands
Classify MET intensity using caller-selected light/moderate/vigorous boundaries.