Åstrand-Ryhming Cycle Ergometer Test

The Åstrand-Ryhming test (Åstrand & Ryhming, 1954; modified by I. Åstrand, 1960) estimates VO2max from the steady-state HR at a single submaximal cycle workload held for 6 minutes at 50 rpm.

Protocol:

• Choose a workload aiming for a steady-state HR of roughly 125–170 bpm (the test's valid range):
  • Common starting loads: men 300–600 kgm·min⁻¹ (50–100 W), women 300–450 kgm·min⁻¹ (50–75 W); fitter individuals start higher. (exact recommended starting loads vary by source)
• Pedal 6 minutes; record HR at the end of minutes 5 and 6; they should agree within ~5 bpm (steady state).
• Use the Åstrand-Ryhming nomogram to read predicted VO2max from the steady-state HR and the workload.
• Multiply by the age-correction factor (because HRmax falls with age): e.g., 15 yr ×1.10, 25 yr ×1.00, 35 yr ×0.87, 40 yr ×0.83, 45 yr ×0.78, 50 yr ×0.75, 55 yr ×0.71, 60 yr ×0.68, 65 yr ×0.65. (exact factors per published table)

Assumptions/limitations: same as other submaximal cycle tests — steady-state HR, linear HR–VO2 relationship, assumed HRmax embedded in the nomogram. HR must land in the valid window (≈125–170 bpm) for the nomogram to apply; beta-blockers and stimulants invalidate it.

• Single workload, 6 min, 50 rpm; HR recorded at min 5–6 (steady state).
• Valid HR window roughly 125–170 bpm.
• VO2max read from the Åstrand-Ryhming nomogram, then multiplied by an age-correction factor (~1.10 at 15 yr down to ~0.65 at 65 yr).
• Same assumptions/limitations as the YMCA cycle test.