# The testing protocol used in this lab consists of a series of 3-minute running bouts on a treadmill as follows:

The testing protocol used in this lab consists of a series of 3-minute running bouts on a treadmill as follows:

A. The first 3-minute bout is of sufficiently low intensity so that the O2 demand is submaximal; that is O2 demand is below the subject’s VO2 max (usually done at 0% grade and at a comfortable running speed). VO2 is measured during the last 30 seconds of the bout, allowing VO2 to reach steady-state during the first 2 minutes of the bout.

B. After a rest period, another 3-minute bout is performed with the treadmill grade increased slightly. Uphill running at any given speed has a higher O2 demand than running on a level treadmill at that given speed. Again, VO2 is measured during the final 30 seconds of this bout, the expectation being that VO2 will increase in response to the increase in O2 demand. If VO2 does increase, subsequent bouts are performed at ever-increasing intensity (increasing grade or speed) until a bout is performed in which VO2 fails to rise in response to the increase in O2 demand. The highest VO2 attained during this series of running bouts is VO2 max.

(Actually, the highest VO2 attained in this protocol is a VO2 peak, but since neither subject is highly trained in any other endurance sport and since running involves a larger amount of muscle mass than other modes of exercise they could perform, it is safe to assume that VO2 peak reached in this running protocol is VO2 max.)

Subject 2 is a 28-year-old female who weighs 119 lb (54 kg) begins her VO2 max test. Intermittent stages consisting of 3-minute treadmill running bouts at progressively increasing intensity with VO2 being measured during the final 30 seconds of each bout. Subject 2 performs her first bout.

Speed = 187 m/min

Analysis of her expired air during the final 30 seconds of Bout 1 shows that her VO2 is 2.13 L/min or 39.5 ml/kg/min.

After a short rest, Subject 2 performs her next bout. The intensity (and O2 demand) of Bout 2 is greater than in Bout 1. The increase in intensity is accomplished by increasing the speed of the treadmill.

Speed = 214 m/min

Analysis of her expired air during the final 30 seconds of Bout 2 shows her VO2 was 2.23 L/min or 41.2 ml/kg/min. Notice that Subject 2’s relative VO2 of 41.2 ml/kg/min is similar to Subject 1’s relative VO2 (40.6 ml/kg/min) at this same speed and 0% grade.

After a rest period, Subject 2 performs her third bout

Speed = 214 m/min

Analysis of her expired air during the final 30 seconds of Bout 3 reveals that her VO2 = 2.37 L/min or 43.9 ml/kg/min.

After a rest period, Subject 2 performs her fourth bout.

Speed = 214 m/min