Timing of baking soda loading, and the future of fatigue research


As of September 2017, new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Check out my bestselling new book on the science of endurance, ENDURE: Mind, Body, and the Curiously Elastic Limits of Human Performance, published in February 2018 with a foreword by Malcolm Gladwell.

- Alex Hutchinson (@sweatscience)


I spent three days last week at a conference called “The Future of Fatigue in Exercise,” hosted by Frank Marino and Rob Duffield at Charles Sturt University in Bathurst, Australia. Lots of interesting presentations and discussions, which I’ll be writing about in various forms over the next few months. To start, I thought I’d share a couple of short “practical” tidbits of research-in-progress that were presented at the conference. First: the timing of baking soda loading.

The practice of taking baking soda to buffer acid-base balance in the blood for short-duration exercise has been around for at least 30 years. It’s commonly used by athletes in events lasting around 2:00 (like 800-metre running), and may also help with repeated-sprint ability. Does it work? The research isn’t clear-cut, but most sports scientists believe that it works to some degree. The problem is that it also messes with your stomach, causing diarrhea and other lovely effects that aren’t conducive to great performance. (Random aside: I actually got my “big break” in university when one of my teammates had to bail out of the 4x800m relay team at the conference championships because he’d taken too much baking soda. I was inserted as a last-minute sub and ran a breakthrough race, earning a spot on the team at nationals. But I digress…)

Anyway, Jason Siegler of the University of Western Sydney presented some data looking at the timing of soda loading. Usually athletes take soda about an hour before competition, so that levels of of bicarbonate in the blood peak roughly when you’re competing. This also happens to be when gastrointestinal symptoms peak. What Siegler and his colleagues had noted in previous experiments was that bicarbonate levels actually stay high for several hours, while stomach problems tend to subside after a few hours.

So they ran a test of repeated sprint ability where the subjects took baking soda either 60, 120 or 180 minutes prior. As expected, the levels of bicarbonate in the volunteers’ blood before exercise were essentially identical no matter when they took the baking soda. The incidence and severity of gastrointestinal symptoms peaked about 90 minutes after taking the soda, and returned to normal after 180 minutes. All three groups performed essentially the same in the sprint test.

I should point out that there was no control group, so this study doesn’t tell us anything about whether the intervention works or not. Also, the stomach problems don’t appear to have hurt performance in the actual sprints, despite reaching an average of 5-6 out of 10 of the scales of incidence and severity. Apparently the volunteers managed to grit their teeth, clench their cheeks, and get the job done despite the discomfort. Still, if I was a middle-distance athlete inclined to try my luck with baking soda (and, for the record, I never did try it — in fact, when I was competing in the 1990s it was briefly listed as a “banned technique” by doping authorities, though they obviously couldn’t make baking soda a “banned substance”) — anyway, if I was using it, these results would certainly encourage me to take it ~3:00 before competition to hopefully give my stomach a chance to settle down.

5 Replies to “Timing of baking soda loading, and the future of fatigue research”

  1. Alex – Fascinating stuff – thanks.
    I’m intrigued to know what effects there might be to combining (in various formats) beetroot juice and baking soda… the mind boggles with complexity…

  2. Hmmm, beetroot juice combined with baking soda… I’d say you’d want a toilet at the halfway point AND at the finish line! 🙂

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