VO₂ Max Testing: What It Is and Why Serious Athletes Get Tested in the Lab

Your watch says your VO2 max is 52. Your friend's says 55, even though you beat them at the last 10km. You start to wonder what the number actually means, and whether it is right.

A lab test answers both questions. Here is what a VO2 max test measures, what happens on the day, how it compares with your watch, and who gets the most out of one.

Photo: SportPlus.sg / Isis Ang

VO2 Max Testing at a Glance

What a Lab Test Measures

VO2 max is the maximum volume of oxygen your body can use during exercise, reported in mL/kg/min: millilitres of oxygen per kilogram of body weight, per minute.

In a lab, you wear a mask that captures your breath while you run or cycle, and the system measures it as the effort climbs. Cleveland Clinic's sports medicine physician describes this kind of test as the reference method for determining VO2 max.

More Than One Number

The headline figure is only part of what you take home. FORGED by ReFormd's VO2max Test gives you:

• Your VO2 Max: Your measured aerobic ceiling.
• A Key Ventilatory Threshold: A marker in your breathing that helps set training intensity.
• Heart Rate Zones: Zones based on your own test to guide how hard you train.
• Fuel Use: Insight into whether you are burning more carbohydrate or fat.

The most useful part of a lab test is not the headline number.

Why Not Just Use a Formula or a Watch?

The 220-Minus-Age Problem

Many training zones still start from the formula 220 minus your age for maximum heart rate. A large 2001 study in the Journal of the American College of Cardiology, pooling 351 studies and 18,712 people, found a better fit was 208 minus 0.7 times age, and that the old formula underestimates maximum heart rate in older adults. A lab test skips the formula entirely.

How Close Is Your Watch?

A 2022 meta-analysis of 14 validation studies in Sports Medicine found that watches estimating VO2 max from exercise, as most running watches do, were close on average across a group. For individuals, though, the error was large, with limits of agreement of roughly 10 mL/kg/min either way. The authors concluded these estimates still need improvement for sport and clinical use. Our article on lab testing vs your watch goes into the detail.

What Happens on Test Day

• Choose Run or Cycle: FORGED by ReFormd tests on either.
• A Maximal Effort: You work up to all-out, and FORGED by ReFormd describes it as a challenging test, so book it for a day when you are fresh.
• The Kit: Your breathing is measured on the Cortex 21® Performance T, and the session takes 60 minutes.
• Where: 1 Raffles Link, #B1-23 CityLink Mall.

Reading Your Result

• Compare With Yourself: VO2 max tends to decline after age 30, by about 5% to 10% per decade, so a single number means more against your own past results than against anyone else's.
• Small Changes Are Noise: Changes of less than 3% to 5% might just reflect natural test variability.
• Retest After a Block: If you are just starting a programme, a 10% to 15% improvement in a few months is realistic, according to Cleveland Clinic.

Test Your Aerobic Ceiling with FORGED by ReFormd on ATHLO+

You can book the VO2max Test with FORGED by ReFormd directly on ATHLO+. If you want your lactate threshold as well, the FUEL Runner's Metabolic Bundle pairs the VO2max Test with the Lactate Threshold Test. Find out more on the FORGED by ReFormd page.

Ready to choose which test to book? Read our guide to booking a VO2 max test in Singapore next.