Lactate Threshold - Increase It to Run Faster

If you learn how to train above your lactate threshold (LT), you can run faster. While runners used to consider lactic acid build-up one bad dude, responsible for The Wall, bonking, that burning feeling in your legs, it's allegedly hydrogen ions that are to blame.

First off, lactic acid is created as you burn glycogen without oxygen on a run. When you're lightly jogging at an aerobic pace, your muscles can burn up lactic acid faster than it's generated. But as you increase your intensity, you hit your LT, the point at which lactic acid builds faster than your muscles can process it. Here's the interesting part, lactic acid is broken down in the blood into lactate and hydrogen ions. Lactate is your friend, converting into fuel by the mitochondria, while an accumulation of hydrogen ions is the enemy delivering muscle burn and fatigue.

By training beyond your LT, you'll run faster for longer as you strengthen your body's ability to process lactic acid into fuel and help buffer those ions. Check out this February 2009 Runners World article for an explanation of LT, as well as suggested workouts to train above your threshold. VeloNews' article on LT and how to find your personal LT from a cycling perspective is also a good read. Hmm ... to this layperson, it's probably good I sent my heart rate soaring for sustained intervals on the treadmill yesterday.