Quick answer: a 40-year-old, 160 lb man who walks a mile in 15:00 and finishes at 140 bpm has an estimated VO2 max of 40.5 ml/kg/min with the Rockport (Kline 1987) equation. A woman with the same numbers gets 34.2.
How to do the test
Find a flat, measured mile: four laps of lane 1 on a 400 m track plus 9.34 m, or a marked path. Warm up with a few minutes of easy walking. Then walk the mile as fast as you can while still walking (no jogging), and stop the clock at the end. Read your heart rate straight away, ideally from a chest strap; in the original study, heart rate was recorded every quarter mile and the value from the last quarter went into the equation. Enter the time, the heart rate, your age, sex and weight above.
The equation
Kline and colleagues tested 343 healthy adults aged 30 to 69 on a treadmill to measure VO2 max, then had each of them walk a mile on a track at least twice. Regression produced this widely used form, quoted in many later studies:
VO2 max (ml/kg/min) = 132.853 - 0.0769 x weight (lb) - 0.3877 x age + 6.315 x sex (1 male, 0 female) - 3.2649 x time (min) - 0.1565 x heart rate (bpm).
Reading the coefficients: every minute faster adds about 3.26 ml/kg/min, every 10 bpm lower at the finish adds about 1.57, and every 10 lb of body weight takes off about 0.77. The paper's abstract reports the litres-per-minute version (r = 0.93, standard error 0.325 L/min), which held up in a separate cross-validation group of 169 people (r = 0.92). The calculator shows that version too, converted to ml/kg/min, so you can compare the two.
Worked example
A 35-year-old woman weighing 140 lb walks the mile in 16:30 (16.5 minutes) and finishes at 150 bpm. 132.853 - 0.0769 x 140 - 0.3877 x 35 + 0 - 3.2649 x 16.5 - 0.1565 x 150 = 132.853 - 10.766 - 13.570 - 53.871 - 23.475 = 31.2 ml/kg/min.
Limits
- It is an estimate from a sub-maximal test, built on people aged 30 to 69. Outside that age range the equation is being stretched beyond its data.
- The heart rate term carries a lot of weight. A wrist sensor that reads 10 bpm off shifts the result by about 1.6 ml/kg/min, and anything else that changes your heart rate, such as some medicines, changes the result.
- Compare results over time on the same course rather than with other people.
- Check with a doctor before hard exercise testing if you have a heart condition, high blood pressure or are new to exercise.
Runners can estimate VO2 max from a 12-minute run, a 1.5-mile run or a race on the VO2 max calculator. To train by heart rate, set your zones with the heart rate zone calculator. Another field test is the Harvard step test.
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(3):253-259; Frontiers in Psychology (2021), executive function and cardiorespiratory fitness in older adults: Rockport equation in ml/kg/min; Medical Journal of the Islamic Republic of Iran (2022), HIIT vs MICT in obese adults: same Kline equation. Rules checked . Found a problem? Tell us.
Questions
What is the Rockport walk test?
A field test where you walk one mile as fast as possible, then use your time, finishing heart rate, age, sex and weight in the Kline et al. (1987) equation to estimate VO2 max.
What is the Rockport walk test formula?
VO2 max = 132.853 - 0.0769 x weight in lb - 0.3877 x age + 6.315 x sex (1 for male, 0 for female) - 3.2649 x time in minutes - 0.1565 x heart rate.
When should I take my heart rate?
At the end of the mile. The original study used the heart rate over the final quarter mile, so a chest strap or a reading in the last minute of the walk matches it best.
Can I jog during the Rockport test?
No. The equation was built from walking, so jogging any part of the mile makes the estimate invalid. If you prefer to run, use a running test such as the Cooper 12-minute run instead.