Ono's guide to building muscle - Biceps

[ono]

Isn't the point of doing high rep exercises and high intensity to improve your lactic acid threshold and improve the ability to remove lactic acid from your muscles? If you don't do any high repetition work your going to get sore very quickly. Like why many gym rats can hardly do 100 body weight squats in a row.

You don't need to improve your lactic acid threshold and you don't need to improve you're body's ability to remove it. It's not as detrimental as once thought. Infact endurance training will improve the capacity to use lactic acid as a fuel during exercise.

So Lactic Acid is actually used as fuel by your body. lactic acid (for ref)

Muscle cells convert glucose/glycogen to lactic acid and it is then used for energy (by the mitochondria).

Endurance training increases the mass of the muscle mitochrondria, which in turn lets you burn more lactic acid.
See:

Gina Kolata suggests more endurance training: “Running longer and longer distances, for example, increases the mass of [an athlete’s] muscle mitochondria, letting them burn more lactic acid and allowing the muscle to work harder and longer.” Almost as an afterthought she adds, “Just before a race, coaches often tell athletes to train very hard in brief spurts.”


That should explain why you don't see many gym rats who can do 100 body squats. Endurance athletes tend to have more slow twitch muscle fibers. Slow twitch muscle fibers have more mitochondria.