VO₂ MAX – WHAT IT IS, AND WHY IT’S CRUCIAL FOR RUNNING PERFORMANCE
Published: 23/01/2026 | By: Priya Gopaldas
Priya Gopaldas is a doctor, ultrarunner, and mountaineer, so she knows a thing or two about pushing her limits – and understanding er body while doing it. In this guide, the Sports Direct ambassador breaks down VO₂ max, that mysterious number on your smartwatch, and shows how it can help you run smarter, train better, and track your progress.
If you’ve ever looked at your smartwatch and seen a “VO₂ max” score staring back at you and had no clue what it means… you’re not alone. I spent a long time ignoring mine. It felt like one of those numbers better suited for elite athletes rather than sitting on my wrist as an everyday runner. However, once I dug into what it meant, how it is tracked/estimated, and its implications for running performance, it became a useful marker to help me understand where I’m at with my fitness.
It’s not something I obsess over – just a helpful indicator that sits alongside how I feel on my runs. This guide breaks it all down in simple terms, so you can use VO₂ max as a guide to track and improve your running, without the need for a sports science degree.
WHAT IS VO₂ MAX?
VO₂ max is the maximum amount of oxygen your body can use during intense aerobic exercise, measured in millilitres of oxygen per kilogram of body weight per minute. Think of it as your aerobic capacity: the higher it is, the more oxygen you can deliver to your working muscles.
Here’s the science, simplified:
Your lungs bring oxygen in.
Your heart pumps that oxygen around the body.
Your muscles use the oxygen to produce ATP (adenosine triphosphate) – your body’s energy currency.
The better your body is at moving and using oxygen, the longer and faster you can run before fatigue sets in. Your VO₂ max is the combination of lung function, heart efficiency, muscle usage, and conditioning all baked into one score.
WHY VO₂ MAX MATTERS FOR RUNNING
A higher VO₂ max means you’ve got a bigger aerobic engine – your heart and lungs can deliver more oxygen to your muscles, which helps you run for longer without everything feeling like a struggle, and allows you to recover more quickly between harder efforts.
It is also strongly linked to cardiovascular health and longevity, which makes it a rather nice marker of overall general health.
That said, a high VO₂ max doesn’t automatically make you the best runner. Running isn’t just about capacity; it’s about efficiency. This is where running economy comes into play.
VO₂ MAX VS RUNNING ECONOMY
Running economy refers to how efficiently your body uses energy to maintain a certain pace. This part of the running equation takes into account technique, strength, coordination, body composition, and physiology.
Some elite runners have average VO₂ max scores but exceptional running economy – they waste very little movement, maintain excellent form, and use oxygen sparingly.
Research on elite marathoners repeatedly shows that efficiency, not VO₂ max alone, separates good runners from world-class ones. It is not uncommon for athletes with lower VO₂ max values to outperform others simply because they are more efficient.
The GOAT of marathon running, Eliud Kipchoge, is a perfect example of this. He has an incredible VO₂ max, but his real superpower is efficiency. He uses oxygen so effectively that he requires less of it to run at a given pace compared to his competitors.
This matters for everyday runners because it means we can improve running economy through strength training, technique work, and smart pacing, even if our VO₂ max isn’t naturally sky-high.
HOW TO MEASURE YOUR VO₂ MAX
- Lab Testing (the best way)
Typically conducted on either a treadmill or a static bike (a treadmill is recommended for runners). You complete a “ramp test” where the intensity gradually increases while wearing a mask that measures exactly how much oxygen you’re consuming.
It’s essentially a “run until you can’t anymore” situation. It’s sweaty and intense, but it provides the most accurate VO₂ max reading.
- Smartwatches
Most smartwatches (Garmin, Apple Watch, COROS) estimate VO₂ max using algorithms based on pace, heart rate, and training data.
These estimates are not as accurate as lab testing and should be viewed as approximations rather than absolute values. That said, they are excellent for tracking trends and monitoring progress over weeks and months.
- DIY Estimates
For a quick estimate, you can use a simple one-mile run or walk test, or an online VO₂ max calculator. These methods aren’t as precise as lab testing or as convenient as smartwatches, but they’re accessible and useful for getting a rough idea of your aerobic capacity – especially if repeated regularly to track progress.
WHAT’S A GOOD VO₂ MAX FOR RUNNERS?
It’s important not to obsess over numbers. Your VO₂ max reflects your potential, but your training determines how much of that potential you actually use.
Two runners with the same VO₂ max can perform very differently depending on their training, running economy, and strength. The ranges below reflect typical VO₂ max values seen in large population fitness datasets:
Women:
- Beginner: 30–40
- Recreational: 40–50
- Competitive: 50–60
- Elite: 60–75+
Men:
- Beginner: 35–45
- Recreational: 45–55
- Competitive: 55–65
- Elite: 65–85+
FACTORS THAT INFLUENCE VO₂ MAX
Male vs Female
Natural differences in body composition play a role. Men generally have more lean muscle mass (which uses oxygen), while women tend to carry a higher proportion of fat mass. As a result, men typically show higher VO₂ max values on average.
That said, elite female athletes can outperform most men – just usually not the very top male endurance athletes.
Age
VO₂ max naturally declines with age, typically by around 5–10% per decade after the age of 30. This is due to reduced muscle mass, less efficient muscle fibres, and a declining ability of the heart to pump oxygenated blood with the same force and speed.
Body Composition
A higher proportion of lean muscle increases VO₂ max because muscle tissue actively consumes oxygen during exercise, whereas fat mass does not. This means runners with lower body fat and greater muscle mass often demonstrate higher aerobic capacity for the same body weight.
Altitude
Training or living at altitude stimulates red blood cell production, increasing the blood’s oxygen-carrying capacity and, over time, improving VO₂ max once back at sea level. However, short-term exposure can temporarily reduce performance while the body adapts to lower oxygen availability.
Sleep
Consistent, high-quality sleep supports cardiovascular function, muscle repair, and metabolic efficiency – all essential for maintaining or improving VO₂ max. Research consistently shows that even short-term sleep restriction can impair aerobic performance and reduce training adaptations.
Mental Training: Drive and Fatigue Resilience
Motivation, mental toughness, and the ability to tolerate discomfort play a significant role in how hard an athlete can push during VO₂-max-level efforts. Psychological resilience can therefore indirectly improve VO₂ max by enabling more consistent, higher-quality training over time.
Lifestyle
Smoking reduces lung capacity and oxygen delivery, directly lowering VO₂ max. A diet rich in carbohydrates, antioxidants, and nitrate-containing vegetables (such as beetroot and leafy greens) has been shown to support VO₂ max. Adequate energy intake and sufficient iron are also essential, as under-fuelling and low iron levels significantly reduce aerobic capacity and training adaptations.
HOW TO IMPROVE YOUR VO₂ MAX
- Endurance Training (the underrated essential)
Easy, conversational miles build the aerobic base that VO₂ max depends on. For most runners – especially beginners – focusing on volume before speed is key.
- Interval and Sprint Training
High-intensity interval training (HIIT) is one of the most effective ways to increase VO₂ max. These sessions force your cardiovascular system to operate near its maximum.
Examples include:
- 400 m track repeats (6–10 reps with recovery)
- Hill sprints (12–20 seconds with full recovery)
- Pyramid intervals (e.g. 1–2–3–2–1 minutes at a hard pace, with equal recovery)
Once a week is plenty; twice if you’re experienced. These sessions are effective only if your easy days truly stay easy, allowing proper recovery.
- VO₂ Max Workouts Based on Race Distance
Shorter races such as the 5 km and 10 km are run at roughly 90–95% of VO₂ max. VO₂ max sessions are therefore highly race-specific and most effective later in a training block.
For half-marathon and marathon runners, race intensity sits well below VO₂ max. VO₂ max work is best developed earlier in training and then maintained, as improving maximal aerobic capacity raises the pace you can sustain at lower intensities.
For longer distances, threshold training – longer, steady efforts just below lactate threshold – should be prioritised to build endurance and efficiency.
- Strength Training and Plyometrics for Better Running Economy
Strength training has been a game-changer in my own running. Stronger legs make each stride smoother, more controlled, and more efficient.
When muscles can produce more force with less effort, you naturally use less oxygen at a given pace, improving running economy. Even two short sessions per week can make a noticeable difference.
Focus on simple lifts such as squats, lunges, and deadlifts, alongside plyometric drills like box jumps or skipping. Strength work not only improves running economy but is also key to injury prevention in runners.
THE BOTTOM LINE
VO₂ max is a useful metric for guiding training and tracking progress, but it should never define your ability, confidence, or enjoyment of running.
Focus on consistent training, proper recovery, strength work, and smart pacing – and your VO₂ max will improve quietly in the background.
I don’t know my exact VO₂ max, but I trust that as I train consistently and effectively, my aerobic capacity improves naturally.
