Åstrand-Ryhming Cycle Ergometer Test Calculator (VO2max)
Estimate VO2max from a single-stage Åstrand-Ryhming cycle ergometer test: workload in watts, steady-state heart rate, sex, age and body weight, with Åstrand's age correction.
How it works
workload (kg·m/min) = watts × 6.12 · Men: VO2max (L/min) = (0.00212 × workload + 0.299) ÷ (0.769 × HR − 48.5) × 100 · Women: (0.00193 × workload + 0.326) ÷ (0.769 × HR − 56.1) × 100 · × Åstrand age factor (1.00 at 25, 0.87 at 35, 0.75 at 50, 0.65 at 65) · relative = L/min × 1000 ÷ kg
In the Åstrand-Ryhming test (1954) you pedal for six minutes at one constant workload chosen to raise your heart rate to 120–170 bpm. Because heart rate rises roughly linearly with oxygen uptake, the steady-state heart rate at a known workload can be extrapolated to an estimated maximum. The equations here reproduce the Åstrand-Ryhming nomogram, and Åstrand's 1960 age-correction factors adjust for the fall in maximum heart rate with age. Expect an error of about ±10–15%.
Worked example
A 30-year-old man weighing 75 kg pedals at 150 W (918 kg·m/min) and settles at 140 bpm: (0.00212 × 918 + 0.299) ÷ (0.769 × 140 − 48.5) × 100 = 3.80 L/min; × age factor 0.935 = 3.55 L/min, or 47.3 mL/kg/min.
Sources: Åstrand PO, Ryhming I. A nomogram for calculation of aerobic capacity from pulse rate during submaximal work. J Appl Physiol 1954 · Topend Sports — Astrand-Rhyming cycle test
Frequently asked questions
How do I do the Åstrand-Ryhming test?
Pedal at 50 rpm (60 rpm on modern protocols) on a calibrated ergometer at one workload for six minutes. Record heart rate at the end of minutes 5 and 6; if they differ by more than 5 bpm, keep going until steady. Use the average.
Which workload should I choose?
One that brings your heart rate to 120–170 bpm, ideally 130–160. Unfit or older people usually start at 50–100 W, fit men at 150–200 W and fit women at 100–150 W.
How accurate is the Åstrand test?
For groups it is reasonable, but individual error is about 10–15% because maximum heart rate varies between people of the same age. Beta-blockers and other heart-rate drugs invalidate it.
What is a good VO2max?
For a 30-year-old, about 42–46 mL/kg/min is good and above 50 excellent for men; for women about 36–40 is good and above 44 excellent. Values drop by roughly 10% per decade.
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This calculator gives an estimate for general fitness and education only. It is not a diagnosis — results from field tests and prediction equations can differ from laboratory measurements, so talk to a doctor or qualified exercise professional before acting on them.