Estimated maximum heart rate (Tanaka, Fox) and five training zones as percent of
Estimated maximum heart rate (Tanaka, Fox) and five training zones as percent of max or by heart-rate reserve (Karvonen).
Answeringour last check, 2026-10-21
1 of 1checks answered this week
751 msmedian answer time
$0.02listed price per call
$0.02price it asked us
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://fitness-calc.x402tookit.com/heart-rate-zones
| Category | Everything else |
|---|---|
| Provider host | fitness-calc.x402tookit.com |
| Networks | eip155:137, eip155:42161, 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 |
|---|---|---|---|---|
| 2026-10-21 | valid payment request | 402 | $0.02 | 751 ms |
Example input (from the provider)
{
"method": "GET",
"queryParams": {
"age": 40,
"restingHr": 60
},
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET"
],
"type": "string"
},
"queryParams": {
"properties": {
"age": {
"description": "Age in years, 10 to 100",
"type": "number"
},
"maxHr": {
"description": "Your measured maximum, if you have one",
"type": "number"
},
"restingHr": {
"description": "Resting heart rate in bpm for the Karvonen reserve method",
"type": "number"
}
},
"required": [
"age"
],
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"age": {
"type": [
"null",
"number"
]
},
"asOf": {
"type": [
"null",
"string"
]
},
"degraded": {
"type": [
"boolean",
"null"
]
},
"disclaimer": {
"type": [
"null",
"string"
]
},
"maxHrFox": {
"type": [
"null",
"number"
]
},
"maxHrMeasured": {},
"maxHrTanaka": {
"type": [
"null",
"number"
]
},
"maxHrUsed": {
"type": [
"null",
"number"
]
},
"method": {
"type": [
"null",
"string"
]
},
"notChecked": {
"items": {
"type": "string"
},
"type": [
"array",
"null"
]
},
"reasons": {
"items": {
"type": "string"
},
"type": [
"array",
"null"
]
},
"reserve": {
"type": [
"null",
"number"
]
},
"restingHr": {
"type": [
"null",
"number"
]
},
"source": {
"type": [
"null",
"string"
]
},
"summary": {
"type": [
"null",
"string"
]
},
"verdict": {
"type": [
"null",
"string"
]
},
"zones": {
"items": {
"properties": {
"bpm": {
"properties": {
"max": {
"type": [
"null",
"number"
]
},
"min": {
"type": [
"null",
"number"
]
}
},
"type": [
"null",
"object"
]
},
"percentOfReserve": {
"type": [
"null",
"string"
]
},
"zone": {
"type": [
"null",
"string"
]
}
},
"type": "object"
},
"type": [
"array",
"null"
]
}
},
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}