Okay, let’s be honest, there are many molecules that could be labeled as exercise’s ‘wonder’ molecule, but let’s get ourselves lost in this one. What’s fascinating about this one is that it was once thought to be inert and didn’t offer any effects; however, much like almost anything in the body that was once thought to do nothing, it has been shown to have profound effects across our body. That molecule is lactate .
Lactate is produced by our cells’ metabolism - specifically, when we use glucose/sugar/carbohydrates for energy, one of the end products of that metabolic pathway is the production of lactate. Lactate has two fates - it can enter the mitochondrion to be used for energy generation, or it can be exported from the cell and recycled by the liver into glucose. At least, those are two of the most common mechanisms. However, more and more research on lactate shows it has many, many more functions within the cells of our body.
Lactate is now implicated in improving brain function by accumulating in the hippocampus of the brain (this is one of the sections of the brain related to memory formation). As lactate accumulates, it increases the gene expression and protein production of key proteins, like VEGF and BDNF. VEGF is a protein that, when it binds other cells, leads to the production of new blood vessels in the brain. Additionally, BDNF has long been known to improve many aspects of brain function, from cognitive ability, improving memory, and more. Another subcellular mechanism is lactate affecting Sirtuin 1 (Sirt1), which then leads to further production (downstream of Sirt1) of mitochondria associated genes, encouraging the production of new mitochondria within the cells.
From a macro perspective, lactate is also associated with reduced anxiety, reduced stress, and reduced depressive symptoms. Not only that, it improves exercise performance - meaning, without lactate, we would be less proficient at exercising and unable to maintain high intensity. Speaking of high intensity, from an exercise standpoint, high intensity interval training, weight lifting at higher repetitions, and other higher intensity exercises that can’t be performed for long periods of time are the best way of stimulating lactate production.
To be certain, lactate is not even close to the only mechanism that offers benefit to our body through exercise, but as a new frontier of investigation, it is a remarkable one.
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