VO2 Max In Ultrarunning

If you are new to running you’re probably hearing a lot about VO2 Max, and how it needs to be strong. I get it—it can sound a little intimidating. But trust me, understanding this concept can take your training to the next level, even if you're not racing at a blistering pace.

What is VO2 Max?

Let’s start with the basics: VO2 Max is the maximum amount of oxygen your body can utilize during intense exercise. In simpler terms, it’s a measure of how efficiently your body can deliver and use oxygen when you’re working hard. Now, you might be thinking, “But most ultramarathons are low intensity, right?” And you’re absolutely right—ultrarunning is all about endurance, pacing, and finding your rhythm over long distances. But here’s where VO2 Max still comes into play.

Even though ultramarathons aren’t about sprinting or high-speed efforts, a strong VO2 Max helps you perform better at those lower intensities. Why? Because it means your body can deliver oxygen more efficiently to your muscles, helping you run longer with less fatigue. That’s key for those long hours on the trail when every step counts. Imagine your VO2 Max is like a ceiling in a home that will always limit how high you can go. Likewise, your aerobic fitness will always be limited by your VO2 Max.

Having a high VO2 Max also improves your recovery. After all, you’re putting in some serious mileage, and you’ll need to recover quickly to keep going. With a higher VO2 Max, your body becomes more efficient at clearing out waste products like lactic acid, which means less soreness and better overall performance.

How do I increase my VO2 Max?

So if you have found yourself training for your first ultramarathon, marathon, or even half, I would recommend incorporating intervals into your training. To receive maximum VO2 Max benefits you’ll need to be pushing your RPE (Rate of Perceived Effort) at about a 9/10 out of 10 for the Work Periods of the interval and walk or slow jog for the Rest Period of the interval. The main thing is you want your heart rate to decrease as fast as possible so most will want to walk. I highly recommend running hill intervals as these will benefit you 2-fold. One, it will require substantially more effort to run uphill which will strengthen your muscles and guarantee your heart rate is elevated enough to effectively increase your VO2 Max and Two, running uphill is actually much easier when it comes to impact on your joints so it will decrease chance of injury.

It's also worth noting to make sure your “easy runs” are run VERY EASY. Easy runs should be the bulk of your training and done at what is called conversational pace or heart rate zone 2. Between building a big aerobic base by running most of your runs in HR Zone 2 and doing intentional speed work and intervals you will create a stronger VO2 Max and great aerobic capacity that will enable you to endure your first ultramarathon.

So, don’t overlook VO2 Max just because you’re not racing at full throttle. It’s a fundamental piece of the training puzzle that you will be grateful you have.

- Coach Danny