Intro to VO2max
Have you ever heard the term ‘VO2max’ and wondered what the heck that even means? Hopefully by the end of this one, you’re all clear on what a VO2 even is!
VO2max refers to the cardiorespiratory system’s ability to intake and deliver oxygen to muscles, and the muscles’ ability to utilize that oxygen. It is measured in milliliters of oxygen per kilogram of bodyweight per minute, so the numbered value is relative.
Why do we care?
Knowing your baseline VO2max can help you understand where your current fitness level is at, which can help:
provide insights into your training
tell you how long you can sustain an intensity level
improve the quality and strategy of your training program
put a number to your body’s energy efficiency, meaning you can measure your fitness over time
VO2max also correlates with positive health outcomes. Being able to use oxygen for energy is a good thing!
How is VO2max measured?
The only accurate way to test VO2max is inside a lab, therefore, this method is likely not the best way for the average gym-goer due to accessibility. Many endurance athletes such as high level cyclists, runners, or swimmers, who have the resources, might choose to have their VO2max tested in a lab at the beginning and end of their training cycles. For the average person, though, it’s probably not necessary.
If you are interested in having your VO2max tested and you can find a lab near you, I do think the data is really interesting and the tests are fun in a type 2 way! If you live near a college with an exercise science program, it’s likely that they have a VO2max testing lab. When I was in school, we were allowed to test ourselves or bring somebody in for our lab group. You could reach out and see if some exercise science students are about to test, or if they offer testing to the community!
Lab Testing
Participants are hooked up to a mask connected to a machine (a metabolic cart) that measures the oxygen inhaled and carbon dioxide exhaled while exercising, usually on a treadmill or a stationary bike.
There are different testing protocol, but in general, the test administrator will gradually increase the difficulty of exercise until the participant either reaches their max or stops the test. Tests are progressive and usually last around 8-12 minutes. The goal is to achieve absolute max, and participants must meet certain criteria to classify as a max test. This means it is possible to test and not reach your true max.
Submaximal Testing
Submaximal tests can still provide valuable insights to your aerobic fitness. You might have even done a submax test before!
These might look like:
the beep test
the YMCA step test
Since accessibility can be an issue with lab testing, some benefits of submaximal testing are:
more accessible
could do it on your own
not expensive
don’t have to reach true max (submax tests are generally ~85% of max)
What about my fitness watch?
Many fitness watches estimate your VO2max based on things like age, sex, and heart rate data. Some studies show various fitness watches have 5-15% VO2max estimation error, so they’re not incredibly accurate. The only way to know your actual VO2max is to get a lab test, but again, you might not necessarily need one if your goals aren’t super specific and you just want to improve your overall fitness.
My personal advice on fitness watches: look for trends over time, but don’t take the estimations with 100% accuracy.
What’s a good VO2max?
VO2max is measured in milliliters of oxygen per kilogram of body weight per minute (mL/kg/min). Since these tests are relative to your body weight, sex, and age, it depends!
In addition, different sports require different VO2max demands. For example, a weightlifter and a cross country skier will require different cardiorespiratory fitness levels. Cross country skiing is very taxing on the cardiorespiratory system, so a higher VO2max would make going faster and farther much easier, and participating in cross country skiing will increase your VO2max in comparison to weightlifting, which rarely, if ever, trains the cardiorespiratory system.
Increasing your VO2max
In very simple terms…train your aerobic system!
Many exercise physiologists recommend interval training. When creating your own protocol, consider things like:
the intensity of the interval, which you can measure via heart rate or zones
the number of intervals, which will likely be dependent on your current and/or desired fitness status
the rest period between intervals, a crucial part in interval training
Some protocols recommend a 3:1 or 4:1 work-rest ratio, which you could definitely try. If you are an athlete in a specific arena, such as running or swimming, you could try adding in an interval specific day to your training.
Some things to remember…
Ultimately, it should always be you versus you. Try not to compare your fitness level to someone else’s.
Your aerobic system is trainable! If you want to train it, you gotta use it. I’d always recommend finding a program to stick to, hiring a coach to help you, or having a buddy to help keep you accountable. You’ll be much more likely to reach your goals with a support system.
Cardio doesn’t kill your gains. It’ll actually probably help them!
Have a topic you want covered? Feel free to send me an email! As always, thanks for reading, and see you next Friday.
Jory
Sources:
ACSM's Guidelines for Exercise Testing and Prescription (11th ed., Vol. 1). (2022).
Noonan, V., & Dean, E. (2000, August). Submaximal Exercise Testing: Clinical Application and Interpretation. Physical Therapy, 80(8).
