Some of the key points:

Lactic Acid is a fuel not a caustic waste product. People have been getting that mixed up for years.

Muscles burn lactic acid to obtain energy.

Lactic acid does not cause “muscle burn" or make your muscles sore.

The theory that; “lack of oxygen to muscles leads to lactic acid, leads it fatigue" is WRONG.

Circuit training in your lactic acid zone will improve performance, not hinder it.

Read the whole impressive and clarifying article. You will still read and hear many of the myths on lactic acid that this article demolishes.