Jerryc wrote:
Quote:
Lactate is not a fuel, period. It could be converted into fuel in the liver via the Cori cycle in a process called gluconeogenesis, but muscles can't directly metabolize lactate.This is not an accurate description of what goes on during exercise. Lactate is most definitely a fuel and probably the most important fuel for competition. Most lactate created during exercise is metabolized in the aerobic system in the muscles after it has been created during glycolysis. In fact it becomes the dominant fuel for a lot of events. Any event that takes place near the threshold is using nearly 100% lactate created by glycolysis and the glycolysis itself as fuel. At or above threshold there is almost no fat metabolized so all the energy originates in glucose either through glycolysis or the subsequent metabolization of the lactate in the aerobic system.
i stand corrected. My distrust of NYT's Kolata has me put on my blinders to the claims within, so I thank you for bringing this to light. When i took biochem in 2004, this was still a phenomenon that was only recently being brought to light and was not taught. The following article may be of interest: http://http://www.ncbi.nlm.nih.gov/pubmed/15131240
That said, it's doubtful that the OP's training causes any over expression of the enzymes involved in muscular oxidation of lactate, given that lactate level probably doesn't even go 1mmol above baseline at low HR.