54. TOPICAL BICARBONATE IS NOT EFFECTIVE

Photo by Clarissa +Watson on Unsplash

During medium and high intensity exercise muscle pH is lowered (H+ ions increase) and this metabolic change leads to fatigue. Sodium Bicarbonate (NaHCO₃) is a alkaline compound, which means that raises pH. So, sodium bicarbonate can be used as an ergogenic supplement to raise blood pH in order to facilitate the exchange of H+ between muscle and blood and so, in turn, raising muscle pH and delaying fatigue.

While sodium bicarbonate supplementation have been generally reported to increase performance involving high intensity effort by 3% on average, its ingestion (as baking soda or capsules) is often associated with gastrointestinal distress. So, many brands are trying to find different solutions to produce bicarbonate supplements which maximise the ergogenic effects on performance while minimizing gastrointestinal distress. One of these solutions is topical bicarbonate, which is applying a bicarbonate lotion on the skin of the muscles that are going to be used during exercise. In this way, bicarbonate should reach the blood through the skin and not the gastrointestinal tract and so we could potentially take the performance benefits of the compound with zero risk of stomach upset.

But does really topical bicarbonate reach the blood and increase exercise performance?

A hot off the press study published by Gurton and Colleagues (Sheffield Hallam University, UK) in 2024 on International Journal of Sport Nutrition and Exercise Metabolism tried to answer this question. (1)

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WHAT DID THEY DO?

• They recruited 10 collegiate male soccer players who in a randomized order performed a high intensity performance test (8x25m repeated sprints) before and after a 90 min simulated soccer match in different days and conditions:

  1. SB-ORAL: ingesting 0.3 g/kg body mass of sodium bicarbonate divided into three equal doses (120, 105 and 90 min before the start of the simulated soccer match).

  1. SB-LOTION: 0.9 g/kg body mass of a lotion containing 33.2% of sodium bicarbonate (so the sodium bicarbonate amount was the same as SB-ORAL: 0.3 g/kg body mass) was applied on lower back and legs at the same timepoints described above.

• Even if the participants were soccer players, the performance marker measured were high intensity efforts (the 8x25m repeated sprints) after a long aerobic effort (the simulated soccer match), which is still relevant for endurance sport like cycling.

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WHAT DID THEY FIND?