Vo2 max is the maximum volume of oxygen that a person can use during intense exercise. This is a metric used to measure an athlete’s level of cardiovascular (heart) fitness. In the endurance world, Vo2 max is the king of physiological data, with bragging rights for the athlete with the highest number.
Vo2 max is tested in a sports laboratory, using specific equipment to measure inhaled and exhaled oxygen during exercise. The test is performed on a treadmill or stationary bike. It’s a test ramped up and up until you cannot push any harder…so I decided to give it a go.
The Vo2 Max Test
Bangkok Hospital Phuket debuted a new sports performance laboratory, located 35 minutes from Thanyapura Health & Sports Resort. I was able to use my own bike on their innovative equipment – mounted on an indoor trainer with both wheels removed. The Cyclus 2 computer software controlled exercise intensity, so no gear changes were required. I wore a small facemask and heart rate monitor to measure oxygen usage and heart rate throughout the test.
Heart rate and oxygen values are recorded after resting. I cycled at 50 Watts for three minutes. The exercise intensity increases by 20 Watts per minute until exhaustion. The first few minutes was easy. It felt like warm up. My heart rate gradually increased as the computer creates a graph of my data.
At 300 W intensity, I’m struggling as my breathing gets heavier and heavier, faster and faster. I looked around for divine intervention as I keep on pedalling. The intensity continues to rise. My body’s struggling for oxygen and exhaling carbon dioxide as fast as possible. The ratio of oxygen to carbon dioxide must be preserved.
At 360 W, I struggled to keep my cadence when knowing the end is near. I shoot a glance at the computer. Exhaustion is around the corner as my heart rate climbs up above 190 bpm. At this point, the body is no longer able to absorb enough oxygen to sustain exercise. It moves to anaerobic (no free oxygen) systems, which fatigues much faster. My legs are turning into lead trying to turn the cranks for the final few times. At 375 W and just over 20 minutes of cycling, I found exhaustion, collapsed over the handlebars and become a dishevelled heap.
We recorded measurements and printed test results after the lengthy cooldown to normality. For this test, the interesting values were:
- Vo2 max: 63 ml/kg/min (the maximum amount of oxygen utilised during the test, divided by body weight)
- Max Heart Rate: 194 bpm (the highest heart rate reached during the test)
- Max Watts: 375 W (the maximum amount of power, measured in Watts, reached during the test)
The values are ranked in the “excellent” category when referring to the general population and the ranking system on the report. Still, it was way off from the pro-cyclists, who have measured Vo2 max values of 80-90 ml/kg/min and pushing maximum Watts of over 500!
Take Home Data
It motivates me to know my Vo2 max and be able to measure my cardiovascular fitness. It encourages the athlete to come back and try to beat the “score’ next time. Combined with maximum Watts and heart rate, the data is used to give an idea of training intensities and zones. Endurance athletes (guests who visit Thanyapura Health & Sports Resort), can find out the percentage of Vo2 max (or maximum) that can be sustained for a period of time. For this, we use a lactate test, which is the next month’s topic.
About the Author
Tom Topham holds a 1st class honours degree in Sports Science (Human Performance) from Brunel University, England. He also comes from a triathlon background, competing as an age-grouper and holds a level 2 triathlon coaching qualification.