CrossFit Atlanta Newsletter
News & Fitness Information from CrossFit Atlanta
February 26, 2007 - Vol 1, Issue 4
Lactic Acid is a metabolic by-product of the anaerobic metabolism of glucose or glycogen in the production of muscle force. As exercise intensity increases the rate of anaerobic energy production increases and the thus the rate of lactic acid production increases. It is the build up of lactic acid in the muscle that causes "the burn" feeling that makes you want to stop and go home to mama.
Athletes and coaches have long known that high intensity interval training improves the ability to operate at high intensities. For decades exercise physiology scientists have theorized about why this happens. They postulate that proper training improves lactate tolerance in several ways, which include: (1) training causes increased numbers of mitochondria in the muscle which allows aerobic energy procduction at higher intensities, and therefore reduces production of lactic acid, and (2) improved blood flow to and from the muscle lead to increased ability to "clear" the lactic acid away from the muscle. For a more scientific discussion, see Lactate Threshold by Stephen Seiler. The "Lactate Theshold" is the intensity level at which blood lactate starts to rise significantly, and the objective of many endurance athletes is to raise their lactate threshold.
Startling new research by George Brooks at UC Berkeley indicates that higher lactate thresholds are seen in properly trained athletes because the trained muscle can actually use lactic acid as a fuel. Brooks
This research simply confirms what elite coaches and athletes have known for ages: that hard and fast interval training improves improves your ability to go hard and fast, recover quickly and then go hard and fast again. At CrossFit, "we bathe in lactic acid," not because the scientists tell us to do so, but because it produces incredible fitness results.
