The scoop on bicarb

A friend and former athlete recently texted me “I read this promo email from The Feed about bicarb and I’ve never tried it but it sounded like it was too good to be true ha.”

This is a genuinely fair question and one that is coming up with increased frequency for a multitude of products and practices - not only for running but for life in general. The wellness movement is picking up momentum every day. Well intentioned or not, this has created an abundance (or overabundance) of products and practices as well as the associated marketing and social media hype that frankly leaves most folks more confused than ever. I’ve seen this with runners looking for an edge or for something to spark their next breakthrough. I’ve seen this with friends and family simply looking for ways to “feel better”. I’ve seen this as a former practicing pediatric oncologist with patients and families looking for a less toxic alternative or desperate for a sliver of hope.

I will admit that I tend to be a minimalist when it comes to these things. There are often simpler solutions or better opportunities that have yet to be tapped. That said, I am not fundamentally opposed to performance enhancing supplements or recovery practices. There are real, well established benefits to certain products in certain situations. The key, and the big challenge, is being able to wade through the marketing and hype to understand exactly who it might benefit and in what situations. More importantly, it is important to understand who it probably WON’T benefit as well as the potential drawbacks to its use. I am realizing that, given my professional experiences, I might be particularly well positioned to help folks navigate this vast, rapidly expanding, and overwhelming new world of wellness opportunities. That will leave me with A LOT to cover.

But today, since the question was about bicarb, we can start with bicarb.

You've probably seen bicarb (most notably the Maurten Bicarb System) trending in running circles and on social media (and in The Feed newsletters). Here I will try to provide an honest, straightforward, and evidence-based explanation of what it does, who it might help, and, more importantly, who it almost certainly won't.

Bottom line up front (TL:DR for the young folk): if you're training for a marathon or half marathon, the current research does not support bicarb helping you (and it will probably upset your gut). If you're racing an 800m, mile, or hard/fast 5K, or doing serious VO2max/threshold intervals, there is some real (though modest) evidence for it.

What it's supposed to do, and why

Sodium bicarbonate (aka bicarb… or baking soda) is an acid buffer that can be taken orally before exercise. During hard, glycolytically-demanding efforts, hydrogen ions (H+) build up in working muscle and contribute to the acidosis that limits performance. This is what leads to that "burning," heavy-legged feeling in the last stretch of a hard interval. Bicarb raises blood pH and bicarbonate levels, which increases the gradient pulling H+ out of the muscle and into the blood. In theory, that delays the point where acidosis becomes limiting.

This is a real, well-studied physiological mechanism and it's not a scam. The question is which events actually rely on that mechanism enough for it to matter.

What the research shows

For events lasting ~45 seconds to 8 minutes there is real, consistent benefit. This is where the evidence is strongest. A comprehensive review of meta-analyses (an "umbrella review," about as high-confidence as sports science synthesis gets) found consistent benefits for peak anaerobic power, anaerobic capacity, muscular endurance, and high-intensity intermittent running in this window. Think 800m, 1500m, mile racing, hard VO2max intervals, and similar efforts where glycolysis is doing heavy lifting.

For continuous running at 5K and longer there is essentially no benefit. This is the newer and more important finding for most of you. A 2025 systematic review and meta-analysis specifically evaluating continuous running performance found negligible effect from a single dose of bicarb. A separate controlled study using the popular Maurten Bicarb System in collegiate distance runners found no measurable improvement in heart rate, perceived effort, blood lactate, or performance, even at an interval pace close to lactate threshold.

For the half and full marathon distance there is a lack of evidence. But the benefit is theoretically implausible, and the risk profile gets worse. Marathon effort is overwhelmingly aerobic, with much lower acid production than 800m–5K racing, so there's less for the buffering mechanism to actually do. Meanwhile, the classic downside of bicarb (GI distress, more below) has more time and more jostling to become a real problem over 26.2 miles than it does over 4–8 minutes.

One interesting wrinkle: it may matter less the fitter you get. Some meta-analyses have found the benefit is measurably smaller in highly trained athletes than in recreational ones — the opposite of the usual "marginal gains for pros" story you hear with most supplements.

For real-world context, bicarb use has genuinely taken off among elite middle-distance and track athletes over the past couple of years following the 2023 launch of Maurten's hydrogel-based delivery system. You'll hear Olympic and world-level 800m/1500m runners reference it in interviews. It's legal (not on WADA's banned list), though it's generated some debate in the sport about whether it crosses into "unfair edge" territory. That's more a values question than a science one. Its use in marathon-focused programs, at any level, is far less established.

The potential drawbacks

Side effects: the classic downside of bicarb is GI distress — bloating, cramping, nausea, diarrhea, occasionally vomiting — and for a meaningful percentage of people, it's bad enough to erase any performance benefit or worse. This is exactly why products like the Maurten Bicarb System exist: they use a hydrogel-and-minitablet delivery system specifically engineered to reduce that stomach-acid interaction. Early data suggests it meaningfully reduces GI symptoms compared to plain bicarb capsules, but it doesn't change the underlying question of whether the event you're racing benefits from buffering in the first place.

Cost: plain sodium bicarbonate (baking soda) is essentially free. The hydrogel-delivery products built to reduce GI risk is a specialty item, not a grocery-store purchase, that comes with a real cost. This matters when the expected benefit for most of you (marathon/half athletes) is close to zero.

So who should try a scoop?

Possibly worth experimenting with (in training, never first on race day): athletes racing 800m to 5K or anyone doing hard VO2max/threshold interval sessions where glycolytic acid production is the limiting factor.

Not worth it: marathon and half-marathon athletes. The mechanism has less to work with at that intensity, the evidence in continuous running specifically shows negligible benefit, and you're carrying real GI risk over a much longer race for a smaller (likely absent) reward.

What we still don't know: how much individual variation in "responder" status matters, and whether repeated/chronic loading protocols (smaller daily doses over several days, rather than one dose pre-race) meaningfully change the calculus for longer events. The research here is much thinner than for single-dose protocols.

Practical dosing note, for anyone experimenting: the standard research protocol is roughly 0.3 g of bicarb per kg of body weight, taken 1–2 hours before the session. Test it in training first, never for the first time on race day, given how much GI tolerance varies person to person.

The TL:DR again

Bicarb is one of the more legitimate "legal performance enhancers" out there, but it is specific to short, hard, glycolytically-demanding efforts. For the marathon and half-marathon training most of you are doing, the current evidence doesn't support it, and the GI risk argues against experimenting with it anyway. Save the mental energy and the money for the things that actually move the needle at your distance.