If you exercise on a bike hard enough you’ll have a lot of lactate surrounding the mitochondria, as a byproduct from oxygen being converted to pyruvate which enters the mitochondria.
If you have trained a lot at maximum fat oxidation at the point before the lactate surrounding the mitochondria increase so much to increase hydrogen and possibly lead to fatigue and stopping the activity… and upregulating lactate receptors over time to improve the ability to bring lactate into the mitochondria.
So you have a lot more MCT1 receptors, and can therefore the lactate outside the mitochondria is transported very quickly and does not accumulate outside. It will show up as a low resting lactate level and a much higher ability to produce force without lactate accumulating outside the mitochondria (which is a lot of lactate in blood stream).
Not only will apparently MCT1 receptors be upregulated… so will MPC, and all of the components in the krebs cycle (mitochondrial respiration) from exercise and optimally so in Inigo’s experience from training at maximum fat oxidation or before lactate starts accumulating a lot.
I produced a slide yesterday as part of a presentation on this that I thought people might like to see a copy of.
I have been doing a bit more reading up on this. I have not checked the results from chatGPT, but I have this link for anyone that is interested (I will be checking the results as I am intending to write a poster in August including information from this).
Basically I am interested in the factors that increase and reduce citrate efflux from the mitochondria via the citrate carrier. What is interesting is that the citrate that travels out of the carrier is protonated meaning it has a single hydrogen with it and only has a 2- charge whereas the citrate that stays in the canonical TCA cycle is not protonated and has a 3- charge. The ration between the two ionic states is controlled by the pH of the mitochondrial matrix and this, therefore, affects the rate at which citrate is exported.
At the normal matrix pH of 7.6 just under 94% of citrate is 3- and about 6% is 2- some is 1- and very little is neutral.