Lactic Acid good for you? A non-story.

I read this a few weeks ago, and basically pushed it aside as a non-story. Then I came across another story about it, so I figured I'd post. Basically, scientists have realized that lactic acid isn't really bad for your muscles. Lactic acid is actually a very potent fuel for muscles. On the surface, it seems pretty crazy and very much a story. We thought lactic acid buildup is what made you hit the wall, now it turns out it's one of the most efficient fuel sources for muscles?

Here's why it doesn't matter. It won't change how we train. You still want to increase the lactic acid threshold, only it doesn't mean you aren't producing lactic acid, it means your muscles are better able to use lactic acid. Endurance training increases mitochondria in muscle cells. Mitochondria burn lactic acid to produce energy for your muscles.

The scientists don't seem to know yet why you hit the wall, and why it coincides with that burning sensation in your muscles. And why, if you increase your lactic acid threshold (by increasing mitochondria), your muscles take longer to burn and you hit the wall later. My suspicion is that lactic acid is good, so long as you've got the mitochondria to burn it. Once you get too much you start getting the negative side-effects. I've got nothing to back that up but a hunch though.

FYI, the first story, by way of Lean & Hungry Fitness does mention that interval training is a good way of building up mitochondria.