Originally Posted by himespau

Lactate is the conjugate base of lactic acid. From a chemical perspective they're essentially the same thing (at least under physiological conditions in bodily fluids). You put lactic acid into water, it donates its proton to water and becomes lactate and the water (or blood, which is mostly water) becomes slightly more acidic. This idea that they're two different things and that's leading people to think that lactic acid is causing muscle burn when what you're really producing is lactate which isn't an acid is complete nonsense caused by a lack of understanding of basic chemistry. I agree that lactic acid (or lactate) is not what's causing muscle burn, but to talk about them like they're two separate things demonstrates a fundamental flaw in the understanding of what's going on in physiological conditions. There are enough free protons floating around in the cytoplasm (where phosphate buffers the pH)/blood (where carbonate - you know dissolved CO2 - buffers pH) that there is no real functional difference between lactate and lactic acid. As far as what's done with it, sure it can feed neurons, but a lot of it goes to the liver where, through gluconeogenesis, it gets turned back into glucose.