Fox Max HR Formula
Calculate named Fox adult population maximum-HR regression and signed actual peak discrepancy; not individual measured maximum, universal sex/gender inference, medical limit or exercise advice.
Description
The Fox 220-minus-age convention is a population estimate.
The Fox 220-minus-age convention is a population estimate. It should remain distinct from a measured peak or a medical limit.1
The returned values include Population regression max heart rate bpm, Signed observed minus population estimate bpm. The How section below explains the calculation, input rules and interpretation.
When to use Fox Max HR Formula
Use Fox Max HR Formula when you need to evaluate the supplied records under the calculation and evidence rules below. No individual maximum, demographic applicability or exercise advice is inferred.
Prepare the observed race, match or training records and the stated units. Supply independently verified rule editions, calibration tables and targets where requested.
How to use Fox Max HR Formula and understand its results
- Prepare the observed race, match or training records and the stated units. Supply independently verified rule editions, calibration tables and targets where requested.
- Enter observedAgeYears, observedPeakHeartRateBpm using the field table and calculation rules, then run the tool.
- Read populationRegressionMaxHeartRateBpm, signedObservedMinusPopulationEstimateBpm. 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 |
|---|---|---|---|
| observedAgeYears | Observed age years | number | Required |
| observedPeakHeartRateBpm | Observed peak heart rate bpm | number | Required |
Enter integer age 18–100 and positive observed peak BPM. Return estimate and signed discrepancy.
estimate=220−age; discrepancy=observedPeak−estimate Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| populationRegressionMaxHeartRateBpm | Population regression max heart rate bpm | number |
| signedObservedMinusPopulationEstimateBpm | Signed observed minus population estimate bpm | number |
{
"input": {
"observedAgeYears": 40,
"observedPeakHeartRateBpm": 170
},
"output": {
"populationRegressionMaxHeartRateBpm": 180,
"signedObservedMinusPopulationEstimateBpm": -10
}
}Limitations and assumptions
No individual maximum, demographic applicability or exercise advice is inferred.
Numeric inputs, where present, 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 Tanaka Max HR Formula: Tanaka’s age regression describes adult population maximum heart rate. An individual observed peak can differ from the regression. For a complementary task, use Gulati Female Max HR Formula: Gulati’s maximum-heart-rate regression comes from a female cohort. Applying that population equation does not identify an individual’s maximum.
References
-
Fox Max HR Formula — tool.io
Similar or alternative tools
- Tanaka Max HR Formula
Tanaka’s age regression describes adult population maximum heart rate. An individual observed peak can differ from the regression.
- Gulati Female Max HR Formula
Gulati’s maximum-heart-rate regression comes from a female cohort. Applying that population equation does not identify an individual’s maximum.