For years, the Body Mass Index (BMI) has been used as an indicator of health. Doctors, fitness professionals and even insurance companies have relied on this simple calculation of weight divided by height to assess risk factors for disease. But a new study published in the British Journal of Sports Medicine challenges this conventional approach – and the results are important to share with you.
Key finding: VO₂max > BMI for predicting health
The new research shows that your cardiorespiratory fitness, measured as VO₂max, is a much more powerful predictor of long-term health and mortality risk than your BMI.
VO₂max refers to the maximum amount of oxygen your body can use during intense exercise. It is considered the gold standard for measuring aerobic fitness. A higher VO₂max means your heart, lungs and muscles are working efficiently and your body is resilient to chronic disease, regardless of weight.
What the study looked at
Researchers analyzed health data on more than 400,000 adults from 20 studies and tracked their VO₂max, BMI and health outcomes over time. They discovered the following:
- People with higher VO₂max levels had a significantly lower risk of mortality from various causes, even if they were classified as overweight or obese by BMI standards.
- Individuals with low VO₂max had a higher risk of mortality even if their BMI was within the “normal” range.
- In short, fitness was a stronger predictor of health than fatness.
This builds on a growing body of evidence suggesting that being “fit and fat” may be healthier than being “thin and unfit.”
Why this matters
BMI is a flawed measurement method. It does not take into account muscle mass, fat distribution or lifestyle habits. A skinny person with little physical activity may still be at risk for cardiovascular disease, while an active person with a higher body weight – mainly due to muscle – may have a much healthier cardiovascular and metabolic profile.
VO₂max, on the other hand, indicates how well your body functions during exercise. It shows how capable your cardiovascular system is – which is crucial to your longevity and daily quality of life.
How to improve your VO₂ maximum
Improving VO₂max is not just for elite athletes – anyone can benefit. Here are a few proven methods:
- Interval Training: High-Intensity Interval Training (HIIT) has been shown to rapidly improve VO₂max. Even low-intensity interval training can be very effective.
- Steady-state cardio: Longer sessions of running, cycling or swimming can also build endurance.
- Strength training with short rest periods: This increases heart rate and supports aerobic development.
- Stay consistent: Progress comes with time and frequency. Even 3 sessions a week can produce measurable changes.
If you only focus on weight loss as a measure of health, it may be time to change your perspective. The latest science tells us that how fit you are matters more than how much you weigh.
So instead of asking, “What is my BMI?” a better question might be: “How is my VO₂max – and what can I do to improve it?
