YMCA Submaximal Cycle Ergometer Test

The YMCA submaximal cycle ergometer test estimates VO2max from the heart-rate response to progressive 3-minute stages on a mechanically braked cycle ergometer at a fixed cadence (50 rpm).

Protocol:

• Stage 1 (warm-up workload): 150 kgm·min⁻¹ (0.5 kp / 25 W).
• The HR at the end of stage 1 (averaged from minutes 2 and 3, steady state) determines the next workload via the YMCA branching table:
  • HR <80 → next stages 750, 900, 1050 kgm·min⁻¹
  • HR 80–89 → 600, 750, 900
  • HR 90–100 → 450, 600, 750
  • HR >100 → 300, 450, 600
• Continue until two consecutive steady-state HRs between 110 bpm and 85% of age-predicted HRmax are obtained, then stop.
• Plot HR vs. workload for those steady-state points, draw the line to age-predicted HRmax (e.g., 220 − age), and read the predicted maximal workload; convert to predicted VO2max.

Assumptions/limitations: steady-state HR at each stage; a linear HR–workload relationship; a standard mechanical efficiency; and an assumed HRmax (the largest error source — see estimating-max-heart-rate). Caffeine, medications (beta-blockers), heat, and anxiety distort HR and thus the estimate. Stop per standard termination criteria or at the 85%-HRmax endpoint.

• 50 rpm; 3-minute stages; workloads set by the HR at the end of stage 1 (branching table).
• Stage 1 = 150 kgm·min⁻¹ (25 W).
• Endpoint: two steady-state HRs between 110 bpm and 85% of age-predicted HRmax.
• Extrapolate HR-vs-workload line to predicted HRmax → predicted max workload → VO2max.
• Main error source: the assumed HRmax; beta-blockers/caffeine invalidate it.

• astrand-rhyming-test — the single-stage nomogram alternative.
• estimating-max-heart-rate — supplies the HRmax the test extrapolates to.
• test-termination-criteria — when to stop early.
• cycling — the training modality counterpart.