Workout of the Day

One Molecule That Controls Your Performance


Join me for a little educational exercise you can do right at home.

Take a seat, and take a few normal breaths in and out; then, breathe out completely and upon a full exhale, hold your breath until you get the strong physical impulse to breathe. Once you feel that urge, go ahead and breathe in and regain your breath.

Depending on your respiratory fitness, somewhere between 5 and 120 seconds into your breath hold, you found your body sending strong signals of “breathe now, fool.” It probably felt uncomfortable, panicky, maybe even caused some of your respiratory muscles to spasm. While intuitively you may think that this is your body begging for oxygen, it’s actually a matter of CO2 (carbon dioxide).

Our cells produce CO2 as a byproduct of metabolism (i.e., any time they’re doing anything, from basic functioning to high-intensity exercise), and when your breathe out, your body gets rid of built up CO2. When it is present in an amount above what your body is adapted to comfortably handle, receptors in your body send strong signals to cause your respiratory system to practically force you to breathe -- this is that unpleasant feeling of panic and loss of control. Whether you’re gasping trying to recover your breath from a maximal effort sprint, or sitting on your couch reading a book, CO2 is the molecule that compels your breathing.

What’s important to note is that just like strength or flexibility, your body’s capacity for CO2 will be different than someone else’s; and, even more importantly, it can change. If we take the above concepts a few steps down the line, we see that your body’s CO2 tolerance not only determines how long your can hold your breath for cool party tricks, but will play a major role in your performance (and your health).

Consider two athletes who produce the exact same amount of CO2 completing a maximal effort one mile run; but athlete number one has a much higher CO2 tolerance than athlete number two. What this means, practically, is that athlete one will need to breathe less at the same relative pace as athlete two. Apply this to a time trial situation, and what you have is a clear performance discrepancy; or, consider how quickly athlete one will recover compared to athlete two. Take this outside of the context of in-gym performance, and we’re talking about a Navy SEAL’s capacity to maintain physical and mental control and composure in a fire fight under high fatigue, a firefighter’s capacity to make quick and effective decisions when lives are on the line, a lifeguard’s ability to move effectively through turbulent waters to rescue a drowning swimmer, or a civilian’s ability to confront a situation that threatens her family with a clear head. Stepping outside of what one may consider the “performance” realm, and we can talk about how things like anxiety and panic disorders are affected by CO2 tolerance, too. It should be no surprise that breathing is about as universally relevant as it gets.

If we’re looking for low hanging fruit (which you should be), this is a goldmine of easy-to-access opportunities to affect your health and performance. Keep your eyes and ears peeled for ways you can tap into this deep well.

- PS


  • “Linda”

  • 10-9-8-7-6-5-4-3-2-1 reps for time:

    • Deadlift 1.5x bodyweight

    • Bench press 1x bodyweight

    • Squat clean .75x bodyweight