# Rockport Walk Test Calculator

> Estimates VO2max from the Rockport Fitness Walking Test (walk one mile, 1609 m, as fast as possible and record the time and finishing heart rate) with the Kline et al. (1987) regression on weight, age, sex, time and heart rate; the result is classified with Cooper Institute age- and sex-specific norms and expressed in METs.

- Calculator id: `rockport-walk-test` · Category: Sports & Fitness (`fitness`) · Tool name: `estimate_vo2max_rockport`
- Canonical page: https://tttkmbb.com/fitness/rockport-walk-test · This document: https://tttkmbb.com/fitness/rockport-walk-test.md · JSON definition: https://tttkmbb.com/fitness/rockport-walk-test.json

## Purpose

Estimates VO2max from the Rockport Fitness Walking Test (walk one mile, 1609 m, as fast as possible and record the time and finishing heart rate) with the Kline et al. (1987) regression on weight, age, sex, time and heart rate; the result is classified with Cooper Institute age- and sex-specific norms and expressed in METs.

**Use when:** Someone completed a timed one-mile walk with a finishing heart rate and wants a VO2max estimate and fitness rating without running or laboratory testing.

**Do not use when:** You have a Cooper 12-minute run distance or resting and maximum heart rates (use vo2-max), the person ran part of the mile or could not walk continuously, or the person is highly trained (the equation is inaccurate above about 60 ml/kg/min); informational, not a medical test.

## Input

| Parameter | Type | Unit | Required | Description |
| --- | --- | --- | --- | --- |
| `sex` | enum: male \| female |  | required | Sex category used to select the formula coefficients. |
| `age_years` | number | years | required | Age in years (the equation was developed on adults aged 30–69). (min 15, max 90) |
| `weight_kg` | number | kg | required | Body weight in kilograms (converted to pounds for the equation). (> 0, max 300) |
| `walk_time_minutes` | number | min | required | Time to walk exactly one mile (1609 m) on a flat course, in decimal minutes (15 min 30 s = 15.5). (min 5, max 40) |
| `heart_rate_bpm` | number | bpm | required | Heart rate immediately at the end of the walk (15-second count × 4, or a monitor). (min 40, max 220) |

## Output

| Field | Type | Unit | Description |
| --- | --- | --- | --- |
| `vo2max_ml_kg_min` | number | ml/kg/min | Kline et al. (1987) Rockport estimate of maximal oxygen uptake. |
| `fitness_category` | string |  | Cooper Institute rating for the person's sex and age group: very poor, poor, fair, good, excellent or superior. |
| `norms_text` | string |  | The age-group thresholds the rating was read from. |
| `mets` | number | MET | vo2max / 3.5 (multiples of resting oxygen uptake). |
| `weight_lb_used` | number | lb | weight_kg / 0.45359237, as entered into the equation. |

## Formula

`vo2max_ml_kg_min = 132.853 − 0.0769 × weight_lb − 0.3877 × age_years + 6.315 × (male = 1, female = 0) − 3.2649 × walk_time_minutes − 0.1565 × heart_rate_bpm; weight_lb = weight_kg / 0.45359237; mets = vo2max / 3.5`

Kline et al. (1987) derived the equation from adults aged 30–69 against treadmill-measured VO2max (r ≈ 0.88, standard error ≈ 5 ml/kg/min); walkers must reach a steady brisk pace and the finishing heart rate must be taken immediately. Norms: Cooper Institute VO2max classification by sex and age group (13–19, 20–29, 30–39, 40–49, 50–59, 60+). Informational, not a medical test.

## Data Sources

- Kline GM et al. (1987) Estimation of VO2max from a one-mile track walk, gender, age, and body weight, Med Sci Sports Exerc 19:253-259 — https://pubmed.ncbi.nlm.nih.gov/3600239/ (peer_reviewed, retrieved 2026-09-24)
- The Cooper Institute – Physical Fitness Specialist Manual: VO2max norms by age and sex (Cooper Institute for Aerobics Research, Dallas) — https://www.cooperinstitute.org/ (reference, retrieved 2026-09-24)
- Wikipedia – VO2 max — https://en.wikipedia.org/wiki/VO2_max (reference, retrieved 2026-09-24)

Data freshness: `static`. Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output.

## API

- `GET https://tttkmbb.com/api/v1/calculate/rockport-walk-test?sex=…&age_years=…&weight_kg=…&walk_time_minutes=…&heart_rate_bpm=…`
- `POST https://tttkmbb.com/api/v1/calculate/rockport-walk-test` with JSON body `{"inputs": {…}}`
- Response: unified envelope (`success`, `request`, `result.values`, `result.units`, `sources`, `freshness`, `timestamp`, `next_actions`, `links`); see https://tttkmbb.com/docs/response-format.md
- Schema: https://tttkmbb.com/api/v1/calculators/rockport-walk-test · OpenAPI operationId `estimate_vo2max_rockport` in https://tttkmbb.com/openapi.json
- Authentication: none. Rate limit: fair use, see https://tttkmbb.com/docs/rate-limits.md.

## MCP

- Server: `https://tttkmbb.com/mcp` (Streamable HTTP, JSON-RPC 2.0, no auth)
- Tool:  `run_calculator` with `{"calculator_id": "rockport-walk-test", "inputs": {…}}`

## Example

- Male, 30 y, 72.57 kg (160 lb), 15:00, 140 bpm: inputs `{"sex":"male","age_years":30,"weight_kg":72.57,"walk_time_minutes":15,"heart_rate_bpm":140}` → `{"weight_lb_used":160,"vo2max_ml_kg_min":44.35,"mets":12.67,"fitness_category":"Good"}`
- Female, 45 y, 65 kg, 17:30, 130 bpm: inputs `{"sex":"female","age_years":45,"weight_kg":65,"walk_time_minutes":17.5,"heart_rate_bpm":130}` → `{"weight_lb_used":143.3,"vo2max_ml_kg_min":26.91,"mets":7.69,"fitness_category":"Fair"}`

```
GET https://tttkmbb.com/api/v1/calculate/rockport-walk-test?sex=male&age_years=30&weight_kg=72.57&walk_time_minutes=15&heart_rate_bpm=140
```

## Limitations

You have a Cooper 12-minute run distance or resting and maximum heart rates (use vo2-max), the person ran part of the mile or could not walk continuously, or the person is highly trained (the equation is inaccurate above about 60 ml/kg/min); informational, not a medical test. Kline et al. (1987) derived the equation from adults aged 30–69 against treadmill-measured VO2max (r ≈ 0.88, standard error ≈ 5 ml/kg/min); walkers must reach a steady brisk pace and the finishing heart rate must be taken immediately. Norms: Cooper Institute VO2max classification by sex and age group (13–19, 20–29, 30–39, 40–49, 50–59, 60+). Informational, not a medical test. All values are computed from the formula above; no measurement or live data is involved.

## FAQ

**How do I enter a time like 14 min 45 s?**

As decimal minutes: 14 + 45/60 = 14.75.

**Why does a higher heart rate lower the estimate?**

For the same walking speed, a higher heart rate means the effort was closer to maximum, implying a lower aerobic capacity; a fit person walks the mile fast with a low heart rate.

**Is the test suitable for young athletes?**

It was validated on 30–69-year-olds and underestimates fit people who cannot raise their heart rate much by walking; use a running test (vo2-max) for them.

## Related

- [VO2 Max Calculator](https://tttkmbb.com/fitness/vo2-max.md) — Cooper 12-minute run and heart-rate ratio estimates.
- [Heart Rate Zone Calculator](https://tttkmbb.com/health/heart-rate-zones.md) — Training zones from maximum and resting heart rate.
- [Calories Burned by Heart Rate Calculator](https://tttkmbb.com/fitness/calories-by-heart-rate.md) — Use the VO2max estimate in the heart-rate calorie equation.