# How is the cycle factor calculated for cardiopulmonary stress testing of sedentary men?

Updated: May 14, 2020
• Author: Kevin McCarthy, RPFT; Chief Editor: Nader Kamangar, MD, FACP, FCCP, FCCM  more...
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For sedentary men, calculate the cycle factor, ie, cycle factor = 50.72 – (0.372 × age), as follows:

• Step 1: Measure the man's weight (W [kg]) and height (H [cm]) in light clothes and without shoes, and record his age (A [y]).

• Step 2: Calculate his normal (predicted) W in kg, ie, normal (predicted) W = (0.79 × H) – 60.7.

• Step 3A: If his actual W equals his normal W, the formula is predicted peak VO2 (mL/min) = actual W × cycle factor.

• Step 3B: If his actual W is less than his normal W, the formula is predicted peak VO2 (mL/min) = [(normal W + actual W)/2] × cycle factor.

• Step 3C: If his actual W exceeds his normal W, the formula is predicted peak VO2 (mL/min) = (normal W × cycle factor) + [6 × (actual W – normal W)].

• Step 4: If a treadmill is used rather than cycle, multiply predicted VO2 by 1.11.