Why VO2 Max Is Different For Women & How To Bolster It

Who wouldn't want to prioritize a key longevity metric when all it takes is your own body? That's the beauty of VO₂ max, which is the maximum amount of oxygen the body can use during intense exercise and a leading factor for accurately predicting life span.

As an indicator of aerobic endurance, VO₂ max can guide everything from an elite athlete's training programs to helping your everyday, health-curious writer (present!) ramp up her fitness level while reaping major longevity benefits. 

It's worth knowing that VO₂ max is something we all naturally lose with age (about 10% every 10 years after the age of 25, if you don't work on it1), meaning it's always a work in progress.

As a performance coach and exercise scientist, Andy Galpin, Ph.D., explained on the mindbodygreen podcast, "It's not just looking at one system or one organ. It is looking at the lungs. It is looking at the heart. It is looking at blood. It is looking at mitochondrial health and tissue… We're looking at everything, and this is one of the reasons why it is such a ubiquitous and robust predictor of life."

While it's great news we're hearing more about this aspect of training and longevity, there's not a lot of talk about VO₂ max and how it specifically relates to women. 

On average, a woman's VO₂ max is around 20% lower than a man's—though a very fit woman can absolutely bypass male levels. 

This boils down to our ability to transport oxygen, which is lower in women due to their higher body fat, lower overall blood volume, and lower hemoglobin. Because muscles use oxygen, and fat does not, higher amounts of fat reduce oxygen demand. Less blood volume and less hemoglobin (our oxygen transportation protein in the blood) mean less oxygen can be moved.

Women's bodies are designed to make it harder to transport and utilize as much oxygen through them at any given moment compared to men, and oxygen demand is generally lower. 

For men and women alike, pushing ourselves to between 80 and 85% of our individualized maximum heart rate supports gains in VO₂ max, while neglecting cardio-focused exercise can turn even the most basic of daily activities into a slog.

One new study2 out of Federal University of São Paulo in Brazil compared female runners with sedentary women between the ages of 20 and 70. They tested VO₂ max, used a DXA scan to measure body composition, and collected data on training and health habits. 

Male studies have shown us that age-related declines in VO₂ max are related to declines in central factors like heart and circulatory function. In this study, though, they found that women were impacted in those same areas plus peripheral limitations such as how effectively their muscles can use oxygen. 

All that's to say that, according to this study, women are at an extra disadvantage in VO₂ max loss with age. 

One hypothesis for this difference is that women have higher amounts of intramuscular adipose tissue, or small amounts of fat within our muscles, which increases with age. Now, this is one small study, and we'll hopefully continue to see more research emerge on VO₂ max and women, but it offers a helpful lens on how differences in the female body impact VO₂ max.

A bit of good news: Your favorite cardio activities are probably already supporting your VO₂ max.

Swimming, sprinting, biking, HIIT training, and rucking are some of the many ways to increase VO₂ max. The key is challenging yourself with difficult workouts that help you reach 80-85% of your heart rate.

You can do 30 seconds on and 30 seconds off, or longer with longer breaks if that feels more accessible. Even 20 minutes of intervals like this has huge payoffs, and training for VO₂ max just once a week is enough to make positive gains. Remember to start at the level that is right for you in order to do it safely.

More good news—it won't take long to reap the benefits of intentional VO₂ max training, which you can continue to build on. "In the first four weeks, you'll see changes. Your rate of increase will slow down after that, but you will see big jumps in the first six to eight weeks. If you can expand your horizon to six months, you will see massive changes," Galpin shared.

It's a use-it-or-lose-it situation, which, unfortunately, may be slightly amplified for women as we age. We have to continue to train hard at every age if VO₂ max is a priority. 

Don't forget—VO₂ max is only one piece of the healthspan and life span puzzle, and we're still learning about it. 

Your fitness routine supports your health in myriad ways, from staying strong and mobile to fostering good metabolic health, a better mood, and glowing skin. The research is clear that staying active throughout life is a polypill for whole-body health, aside from what level of VO₂ max you're able to achieve.