While mountain biking delivers a lot of great feelings for us, there is one that most riders dread more than anything else – the panicky “I can’t catch my breath” feeling that you can get during a hard climb or sprint. Everyone who has ridden knows this feeling and how it can stop you in your tracks until you can catch your breath and let it pass.

While this sucks, what is even worse is that conventional cardio training doesn’t help with this problem. While it is highly useful, regular cardio (including interval training) focuses more on preventing you from running out of gas than on dealing with this specific problem.

To address this problem you need to focus on your body’s tolerance to Carbon Dioxide (CO2). When you start to work hard the levels of this “waste” gas go up and when they get past a certain level it sends a signal to your brain to start in with the panicky feeling until you slow down and those levels drop again.

We’ve all been there – you are almost to the top of a tough climb and your heart rate is through the roof. Your legs are burning and everything hurts but the real problem is that you are about to panic from the feeling of suffocation. You’re breathing as hard as you can but it isn’t enough and you have to slow down or even stop because you can’t catch your breath.

But after catching your breath and recovering for a minute to two you are just fine. You can get back on your bike and start pushing hard again now that the feeling has passed. In this case you didn’t run out of gas because you still had plenty in the tank. When you bonk and run out of gas it doesn’t matter how long you rest, you just aren’t going to be able to ride very hard.

Again, what happened is that as you were working hard to get up that hill your body was using oxygen to create energy and, as part of that process, producing CO2. As you use more oxygen and your O2 levels drop you see a rise in CO2 levels. And it is the rising levels of CO2 that your body uses to monitor how much oxygen you have in your blood.

As your CO2 levels rise you eventually trigger the “I can’t breath” feeling, which starts the cycle I described above. However, like most things with your body these levels are set conservatively and through training can be raised. This improves your CO2 tolerance and lets you push longer and harder before triggering that feeling.

One of the other benefits of having a higher CO2 tolerance is that being able to tolerate more CO2 allows your body to make better use of the oxygen in your blood. Since your body uses CO2 to “unlock” oxygen from red blood cells, having a higher CO2 tolerance will create an environment that makes it easier to get more oxygen to working muscles. 

So while improving your CO2 tolerance is obviously important, the question now is what is the best way to do it? If regular cardio and intervals don’t improve this important aspect of performance on the trail then what will?

The answer lies in a training method that isn’t very popular with “regular” people but is gaining popularity in scientific and athletic circles. This method involves holding your breath while you perform your cardio exercises in order to expose your body to high levels of CO2 on purpose.

By systematically doing this you give your body a chance to get used to these higher levels of CO2. This will cause a shift upward in your CO2 tolerance while also giving you the chance to create better mental strength to deal with that “I can’t breathe” feeling.

An easy way to do this is to do what I call CO2 Tolerance Intervals. They involve holding your breath and then performing some sort of cardio exercise. Running, riding your bike or even just doing some jumping jacks can do the trick.

To perform this type of interval you would take a breath in and then breath out comfortably. This is a “normal” exhale and not an attempt to empty your lungs. It will be about an 80% exhale for most people.

After you have exhaled you start your interval. Run, ride or whatever else you are doing, starting out easy and picking up the pace until you are going all out. Keep going until you start to feel a strong urge to breathe (called “air hunger”).

At that point stop and try to only breathe through your nose as you recover. After a minute or so you should be back to normal and ready to start your next interval. Repeat that process four more times for five total intervals.

If you have access to an O2 meter then you can wear it and see what happens to your oxygen saturation levels. The goal is to get it down to 85% or lower, which will create a similar internal environment as being at 14,000+ feet. Please note that it may take a few workouts until you are able to get your O2 levels this low but you are still getting benefits from the intervals in the meantime.

I believe that this type of cardio training represents a huge hole in most rider’s training programs. While the science is there, few coaches have come across it yet or been exposed to coaches who have. This means that most riders don’t know how to take control of the easiest and most powerful tool available to them – their own breathing.

Next week I’ll be releasing my newest program – The Better Breathing for MTB Program. In this program I share everything you need to assess your breathing, understand what your dysfunctions are and how to fix them. I also go over how to apply this stuff to your workouts and rides so you know how to get the most out of your breathing on and off the bike.

Until next time…

Ride Strong,

James Wilson