If you've searched "how to improve VO2 max," you've probably noticed that most of what comes back is written for cyclists, rowers, and general fitness-tracker owners — stationary bike protocols, rowing-machine intervals, generic cardio advice that has nothing to do with training for a road race. This page is the running-specific answer. It's about two numbers that explain a lot of why runners with a similar fitness level can post very different race times — VO2 max and running economy — and how running-based training moves each one. It isn't a general survey of every method out there; if you're looking for cycling, swimming or general HIIT protocols, this isn't that page. Everything below stays in the lane RaceRove already covers: running workouts, running training plans, and running races.
What VO2 Max Actually Is
VO2 max is the maximum rate at which your body can take in and use oxygen during hard exercise. It's usually reported in milliliters of oxygen per kilogram of body weight per minute, and it's a widely cited marker of your aerobic fitness ceiling — the upper limit on how much oxygen your heart, lungs and muscles can deliver and burn when you're working about as hard as you can sustain for several minutes.
Two runners can post a similar VO2 max number and still run very different race times. That isn't a contradiction — it just means VO2 max is a ceiling on potential, not the whole story of race performance. How close a runner actually gets to that ceiling, and how much oxygen it costs them to hold a given pace, comes down to a second concept that matters just as much: running economy.
What Running Economy Is, and Why It Matters as Much as VO2 Max
Running economy is how efficiently you use oxygen at a given pace. Where VO2 max asks how much oxygen your body can process at its absolute limit, running economy asks a more everyday question: how much oxygen does it cost you to hold, say, an 8-minute mile? That cost varies a lot between runners, even ones with a similar aerobic ceiling.
A runner with excellent running economy can race faster than someone with a higher VO2 max but poor economy, simply because they aren't wasting oxygen on things that don't move them forward — excess vertical bounce, overstriding out in front of the body, a cadence slow enough that every stride spends extra time on the ground. None of that shows up on a lab VO2 max test, but all of it shows up on race day.
Form work is one of the most direct levers on running economy, and it gets a full treatment in Running Form: Cadence and Breathing — cadence, posture, arm swing and breathing patterns all feed into how much oxygen a given pace costs you.
How Interval Training Improves VO2 Max
The most direct, well-established way to raise VO2 max over a training block is interval training: hard efforts run near or above your current VO2 max pace, repeated with an easy jog or rest between each one. The recovery is what makes the stimulus work — it lets you hold an intensity you couldn't sustain continuously, and repeating that hard effort several times in one session, across a training block, is what drives your VO2 max upward over time.
The mechanics of interval structure — how rep length, pace and recovery differ from a tempo run or a fartlek — are already covered in the interval-run section of Running Workout Types Explained, so this page won't re-explain it from scratch. The short version for VO2 max purposes: hard, relatively short repeats at an effort you could only hold for a handful of minutes are a commonly used VO2 max stimulus, worked into a training block once or twice a week rather than every day.
How Tempo and Threshold Work Improves Running Economy
Where intervals push near or above VO2 max, tempo and threshold work sit lower: sustained efforts at a comfortably hard pace, held continuously instead of broken into repeats with recovery. That sustained time at threshold effort trains your body to use oxygen more efficiently at a given speed — over a training block, the same pace starts to cost less oxygen, which is essentially what improved running economy means.
This is a slower-building adaptation than the VO2 max response to interval work. Threshold training doesn't move the needle in a single session, or even in a single week, and it's easy to underrate because the change shows up gradually instead of after one dramatic workout. It's a real adaptation all the same — it just rewards consistency across a training block rather than any one hard effort.
Other Factors That Influence Running Economy
Interval and tempo work aren't the only levers on running economy. A few other factors are worth knowing about, even if each gets a fuller treatment elsewhere on RaceRove:
- Running form and cadence. Overstriding, excess vertical bounce and a low cadence all cost extra oxygen at a given pace — see Running Form: Cadence and Breathing for what to actually change.
- Consistent mileage over months and years. Running economy tends to improve gradually with training age — the accumulated years of running behind you, not just the current training block — so it isn't something a few weeks of any single workout type can force.
- Running-specific strength work. Strength and core work that targets the muscles and tendons involved in each stride plays a role in how efficiently that stride uses oxygen — see Strength Training and Core Work for Runners for what that looks like in practice.
None of these replace interval or tempo training; they work alongside it. That's a large part of why a well-built training plan touches more than one of these levers at once, rather than betting everything on a single workout type.
Setting Realistic Expectations
Both VO2 max and running economy improve with consistent training over months, not weeks. A single workout type — even a well-executed interval session — isn't going to transform either number on its own. Both respond to a training block built around them and repeated over a meaningful stretch of time, not to one standout workout.
It's also worth naming what a GPS watch's own VO2 max estimate actually is: an algorithm's guess, built from your pace and heart-rate data, not a lab-measured value from a test with breathing gas analysis. It can be a reasonable trend indicator from the same device over time, but chasing a specific number on a watch is less useful than a simpler question — does training and racing feel easier than it used to, and is your performance actually improving over time? That's the read that matters, whatever the wrist estimate says on any given morning.
Building This Into a Normal Training Week
None of this means turning every run into a hard effort. A week built around one interval session, one tempo or threshold session, a long run, and the rest easy running or full rest covers both the VO2 max stimulus and the running economy stimulus, without stacking hard days on top of each other or crowding out the easy volume everything else depends on.
| Session | How often | What it mainly targets |
|---|---|---|
| Interval session | Once, sometimes twice, per week | VO2 max |
| Tempo or threshold run | Once per week | Running economy, lactate threshold |
| Long run | Once per week | Endurance, time on feet |
| Easy running | Most of the week's remaining mileage | Aerobic base, recovery between hard days |
Most of the training-plan structure already covered elsewhere on RaceRove's blog is built around exactly this balance — see Training Plans by Distance for how it plays out week by week at 5K, 10K, half marathon and marathon distances specifically, including how the mix shifts depending on which one you're building toward.
Once you've got a distance and a training block in mind, the next step is picking a race to point it at. Browse 5K races, 10K races, half marathons or marathons, or start from the full list of states if you're not sure yet where you'll be racing.