Lactate in Sports Nutrition: Can Fermented Foods Fuel Performance?
Lactate is having a moment.
It has been discussed in connection with the Tour de France, new sports nutrition products and the changing way scientists understand exercise metabolism.
But one question matters to anyone who prefers real food:
Could natural lactates from fermented foods provide energy like a lactate gel?
The short answer is: chemically, they contain the same basic molecule. Nutritionally, they are not equivalent.
A lactate gel combines a measured dose of lactate with rapidly absorbed carbohydrate and usually sodium. Fermented foods contain much smaller and more variable amounts of lactate, alongside their other ingredients.
At Yanaa, this question is particularly interesting. Anouck, our chef and certified nutritionist, loves fermentation in her kitchen. Chris, our engineer, bio-designer and endurance athlete, fries up his sourdough starter discard for breakfast every morning.
So we wanted to understand what is known - and what remains speculation.
How could lactate provide energy during cycling?
During exercise, glucose and fructose are absorbed through different transport systems in the intestine. Glucose mainly uses the SGLT1 transporter, while fructose mainly uses GLUT5.
This is why combining glucose and fructose can increase carbohydrate delivery compared with relying on glucose alone. But these pathways have limits, and their capacity varies between athletes.
Lactate is different.
Lactate can be absorbed through monocarboxylate transport systems in the intestine and transported to working tissues. In muscle, lactate is handled through transporters including MCT1 and MCT4. It can then be converted back into pyruvate and oxidised in the mitochondria to help produce energy.
In theory, this gives lactate an additional route into the body’s energy system - alongside glucose and fructose, rather than competing for exactly the same transporters.
This is the “lactate shuttle”: lactate moves between cells and tissues, becoming a usable fuel rather than simply a waste product.
However, the important distinction is between a plausible mechanism and a proven performance advantage.
Research suggests that orally consumed lactate can be absorbed and oxidised. It has not yet established that adding lactate reliably increases the total amount of energy an athlete can use during endurance exercise.
You can read more about the research on lactate transport and carbohydrate oxidation in sports drinks and the role of muscle lactate transporters.
What is lactate?
Lactate is a normal part of human energy metabolism.
During exercise, especially when carbohydrate is being broken down quickly, muscles produce lactate. It can then be transported and used as fuel by other muscles, the heart and other tissues.
Lactate is also used to measure exercise intensity. A lactate threshold test can help identify how the body responds to increasing effort.
But the lactate produced by your body during exercise is not exactly the same, in its context of use, as lactate consumed in a food or supplement.
How does fermentation produce lactate?
Lactic-acid bacteria, including species historically grouped under Lactobacillus, use sugars in food as an energy source.
They convert sugars into pyruvate and then into lactate through an enzyme called lactate dehydrogenase. This allows the bacteria to regenerate NAD+, which they need to continue producing energy.
The lactate and lactic acid produced during fermentation lower the food’s pH. That creates the familiar sour taste and makes the food less hospitable to many unwanted microorganisms.
This is the science behind yoghurt, kefir, sauerkraut, fermented vegetables and sourdough.
Fermentation starts in the kitchen
At Yanaa, fermentation is not just a scientific concept.
Anouck loves the slow transformation of simple ingredients in her kitchen. A cabbage becomes sauerkraut. Milk becomes yoghurt. Flour, water and time become sourdough.
Chris starts every morning with sourdough - a breakfast made possible by the partnership between wild yeasts and lactic-acid bacteria.
The chemistry is complex. The ingredients are not.
Would natural lactates work like a lactate gel?
Not in any predictable or dose-equivalent way.
The lactate gel currently attracting attention combines approximately 8 g of lactate with around 90 g of rapidly absorbed carbohydrate and sodium. That is a carefully formulated product designed to deliver known quantities during exercise.
Fermented foods are different. Their lactate content depends on the food, bacteria, fermentation time, temperature, storage and processing.
The most important point is this:
There is currently no evidence that the lactate naturally present in fermented foods improves endurance performance.
Research on isolated lactate supplements is limited and mixed. A 2024 pilot study involving 15 recreationally active adults found no improvement in VO₂ peak, ventilatory threshold or lactate-threshold power. It did find a modest increase in average power during a 20-minute cycling time trial.
Read the study here: Oral Lactate Supplementation and Cycling Performance.
That study tested a measured lactate supplement - not yoghurt, sourdough, sauerkraut or fermented chickpeas.
So the practical answer is:
Natural fermented foods may contain the same basic lactate molecule, but they are not reliable replacements for a lactate gel.
What should athletes take from this?
For now, fermented foods should be enjoyed as food - not as proven lactate supplements.
Yoghurt can be a useful breakfast or recovery snack. Sourdough can provide carbohydrate before training. Fermented vegetables can add flavour to an everyday meal.
But none should be assumed to deliver the same effect as a measured lactate gel.
For endurance performance, the fundamentals remain more important:
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Enough carbohydrate for the work being done
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Adequate hydration and sodium
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Food that your stomach tolerates
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A fuelling plan tested in training
Yanaa’s Science & Research page explores why sports nutrition needs to consider digestion, recovery and long-term health - not just isolated numbers.
The Yanaa view
Lactate may be the new conversation in sports nutrition, but fermentation is an old conversation in the kitchen.
Anouck loves watching fermentation transform food slowly and naturally. Chris still makes and eats sourdough every morning.
The lactate in fermented foods may eventually reveal interesting applications in sports nutrition. At the moment, those benefits are unknown.
So enjoy the yoghurt. Feed the sourdough starter. Put sauerkraut on your potatoes.
Just do it because it is good food - not because anyone has proved that its lactate will make you faster.
You are not an astronaut.
You are a human being, eating breakfast, riding a bike and trying to fuel well.
