Is bicarbonate worth the side-effects?

The use of sodium bicarbonate as a sports supplement for high-intensity endurance exercise such as short-distance time trialling/sprinting has been known about for donkeys.

However, despite the fact that there’s good scientific evidence to support its use, bicarbonate supplementation has never gained widespread popularity in the way that, say, creatine has. That’s because bicarbonate use can be accompanied by unpleasant side-effects such as nausea and gastric distress – severe enough in many cases to be counterproductive.

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But to make matters worse, the side- effects of bicarbonate supplementation are a bit of a lottery; what helps produce a PB for one person could leave someone throwing up!

However, the potential of bicarbonate to seriously improve performance remains, so in an effort to understand more about individual responses to bicarbonate supplementation, scientists from Nottingham Trent University have been studying bicarbonate’s effects on male cyclists.

The science
In the study, researchers looked to see whether the degree of gastrointestinal (GI) distress – nausea, sickness, vomiting – experienced was directly linked to cycling performance and also whether there were any metabolic indicators where cyclists would respond well (or less well) to bicarbonate supplementation.

To do this, 21 male cyclists completed two cycling capacity tests at 110 per cent of sustainable maximum power (hard!). They were supplemented with 0.3g of bicarbonate per kilo of body weight in one trial and an inert placebo in the other, but they didn’t know which was used in each trial. Before, immediately afterwards and then again five minutes afterwards, the cyclists has their blood analysed for acidity/alkalinity, bicarbonate and how much fatiguing lactate had accumulated.

In a nutshell
When the researchers took the group as a whole, bicarbonate supplementation didn’t seem to significantly improve performance. However, four of the group suffered from gastrointestinal distress; when the researchers removed them and analysed the results of the remaining 17, the bicarbonate supplementation proved very effective at boosting total work performed.

Another finding was that, immediately after the test, the levels of blood lactate were significantly higher in the 17 cyclists who took bicarbonate and didn’t suffer GI distress. However, in the cyclists who suffered GI distress, lactate levels were no higher than when the placebo was taken.

So what?
These findings show that if bicarbonate works for you, it’s likely to work very well. But if you’re in the minority who suffer GI distress, you’ll feel too ill to benefit! The fact that the cyclists who suffered GI distress after bicarbonate couldn’t generate more lactate in the test suggests they just couldn’t push hard enough to benefit – almost certainly due to their symptoms.

The bad news is that there’s no predictive test as to the good and bad bicarbonate responders. However, the good news is that the side-effects are temporary and are unlikely to result in worse performance than taking nothing. If you try it and don’t suffer GI distress, it’s likely you’ll reap significant performance rewards!

Int J Sports Physiol Perform. 2013 Oct 23.

This article was first published in the December 5 issue of Cycling Weekly. Read Cycling Weekly magazine on the day of release where ever you are in the world International digital edition, UK digital edition. And if you like us, rate us!