Is your VO2 Max score lying? Discover potential flaws in the mathematics behind the metric.

Two main ways to measure VO2 max

First, it will help you understand the difference between the two common ways physiologists report VO2 max.

• Absolute VO2 max It measures your maximum oxygen uptake per minute and is usually expressed in liters per minute.
• relative VO2 max Divide that number by your total weight. Usually expressed in milliliters/kilograms/minute.

Relative VO2 max is the most commonly seen measurement. Its purpose is to level the playing field and provide comparative measurements. This is because heavier people generally consume more oxygen and have higher absolute measurements of VO2 max than smaller people, they said. Kate BairdCSCS, running and metabolic testing coordinator and exercise physiologist at New York City Hospital for Special Surgery.

Weight calculation problems

Traditional relative VO2 max scores treat all body weights the same, whether lean muscle or fat. Why does that matter? dominate Baird explains that the body’s oxygen consumption during exercise and fat (also known as adipose tissue) does not contribute at all to oxygen utilization.

As far back as 2015, researchers investigated the relationship between VO2 max and body composition and size. After performing a series of exercise tests on young subjects, researchers found no linear relationship between total body weight and VO2 max, but a linear relationship between lean body mass (muscle) and VO2 max. They conclude that it is more reasonable to consider lean body mass rather than total body mass.

2021 Review supported these findings and stated that the common relative VO2 max formula (milligrams/min per kg of body weight) assumes that VO2 max is directly proportional to total body weight, when evidence suggests that the relationship is not linear. (It’s also worth noting that recent research has shown an association between lean muscle mass and higher VO2 max, which may be especially important to keep in mind for older adults.)

Essentially, research agrees that the current formula for relative VO2 max (absolute VO2 max divided by total body weight) is not as accurate a measure of fitness as it appears.

What this means for runners

Runner’s World We investigated these findings They first appeared over a decade ago. But the debate surrounding this metric is now more important than ever. Baird points out that wearable technology displays VO2 max estimates directly on the wrist and alerts runners to any noticeable changes, making it easier for runners to treat that number as the ultimate measure of their overall fitness.

That is why it is important to know the nuances included in this indicator.

First, your weight can affect how your VO2 max is displayed on your watch, Baird says. “If you gain some form of weight, but your fitness doesn’t change, your relative VO2 max will decrease,” she explains. “If you lose weight and nothing changes in your fitness, you’ll gain more weight. That’s how the math works.”

However, that doesn’t necessarily mean your aerobic capacity has gotten worse or better. It just means that the calculation changes based on your weight.

This helps explain why athletes in different sports look so different in terms of relative VO2 max, Baird continues. Elite marathoners tend to have higher relative VO2 max values ​​because they are smaller and lighter. On the other hand, athletes who typically have more muscle mass, such as rowers, often have lower relative VO2 max values ​​than marathon runners, despite having higher absolute values.

This limitation is why the researchers mentioned above suggested using lean body mass, or even higher body mass. complex scaling model– Instead of total body weight in relative VO2 max calculations.

“If it’s about muscle mass, or how much oxygen you can use per kilogram of lean body mass, I think that’s a good way to compare athletes, but I’m not sure it’s that personally discerning on a day-to-day level,” Baird says. In theory, these approaches provide physiologically more accurate relative measurements. In reality, it doesn’t change how runners should think about their fitness, weight, and training strategy, she explains.

Regardless of whether the relative measurement is calculated using total body weight or muscle mass, VO2 max is just one piece of the performance puzzle. Long-distance runners also need to focus on lactate threshold, running economy, and endurance to achieve their best times.

When it comes to overall health and aging, VO2 max is strongly related It provides long-term health outcomes, including reduced risk of cardiovascular disease and improved longevity.

But Baird still cautions against getting hung up on numbers. “The aerobic engine is not the only consideration,” she says. “Sleep, mental health, musculoskeletal health, there’s so much more to do.” [a healthy lifestyle] VO2 max exceeded. ”

In other words, pursuing a higher relative VO2 max score, whether by losing weight or completely changing your calculations, does not automatically lead to improved health.

takeout

Yes, evidence suggests that traditional methods of calculating relative VO2 max have limitations. Cardiovascular fitness may be underestimated in heavier or more muscular people, but switching to a more precise formula doesn’t change the way you train, Baird says. The VO2 max workouts you know and love will help you raise your aerobic ceiling no matter the situation. how The numbers will be calculated.

If your goal is to improve your aerobic fitness, the same basics always apply.

Baird, who is an exercise physiologist himself, emphasizes that for most people, including runners, simply staying active and maintaining a balanced routine is far more important for both aerobic fitness and overall health than trying to optimize this metric or manipulate how to improve your score.