Estimated maximum heart rate by Tanaka, Fox or Gulati formula and five training
Estimated maximum heart rate by Tanaka, Fox or Gulati formula and five training zones in beats per minute, with Karvonen reserve zones when resting rate is given
Answers HTTP 404 without x402 payment termsour last check, 2026-10-18
0 of 1checks answered this week
n/amedian answer time
$0.01listed price per call
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Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
GET https://saylorinnovations.com/api/health/heart-rate-zones
| Category | Everything else |
|---|---|
| Provider host | saylorinnovations.com |
| Networks | eip155:8453, solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp |
| Payment schemes | exact |
| Self-reported calls, 30 days | 1 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-10-18 | no x402 terms | 404 | 219 ms |
Example input (from the provider)
{
"method": "GET",
"queryParams": {
"age": "35",
"resting_hr": "60"
},
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET",
"POST",
"PUT",
"PATCH",
"DELETE",
"HEAD"
],
"type": "string"
},
"queryParams": {
"properties": {
"age": {
"description": "Age in years",
"type": "string"
},
"resting_hr": {
"description": "optional resting heart rate for Karvonen zones",
"type": "string"
}
},
"required": [
"age"
],
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"age": {
"type": "number"
},
"estimated_max_hr": {
"description": "Estimated max hr",
"type": "number"
},
"fat_burn_range_bpm": {
"description": "Fat burn range bpm",
"type": "array"
},
"heart_rate_reserve": {
"description": "Heart rate reserve",
"type": [
"number",
"null"
]
},
"method": {
"description": "Method used",
"type": "string"
},
"note": {
"description": "Caveat or context for reading the result",
"type": "string"
},
"resting_hr": {
"description": "Resting hr",
"type": [
"number",
"null"
]
},
"resting_hr_category": {
"description": "Resting hr category",
"type": [
"string",
"null"
]
},
"source": {
"description": "Data source the values come from",
"type": "string"
},
"vo2_max_estimate": {
"description": "Vo2 max estimate",
"type": [
"number",
"null"
]
},
"zone_method": {
"description": "Zone method",
"type": "string"
},
"zones": {
"type": "array"
}
},
"required": [
"age",
"estimated_max_hr",
"zones"
],
"type": "object"
},
"type": {
"const": "json",
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}