During steady-state exercise on a friction-type cycle ergometer, what is the estimated VO2 for a 70kg individual working at 150 Watts?

To estimate the VO2 during steady-state exercise on a friction-type cycle ergometer, a common approach is to use an equation that relates power output (in Watts) to oxygen consumption (VO2 in liters per minute). For cycling, a rough estimate is that for each Watt of power output, approximately 0.01 L/min of VO2 is required, along with additional components to account for the individual's body weight and efficiency.

In this scenario, we can calculate the VO2 using the following approach:

1. Conversion of Watts to VO2: For cycling, a common estimate is that VO2 increases by about 0.012 to 0.015 L/min per watt of power output. Using an average factor (let’s take 0.012 L/min per watt) provides a basic estimation. At 150 Watts:

• VO2 from power output = 150 Watts × 0.012 L/min/Watt = 1.8 L/min.

2. Adjustment for Body Weight: The oxygen cost of cycling also considers the body weight of the individual:

• An additional estimate often involves body weight; roughly, 0.01 to 0.015 L/min might be added per kg of body