Training to avoid lactic burn

Runners have long been wary about lactic acid. We’ve always viewed it as something that tires us out during a race and makes us sore afterwards.

Recent studies, however, show that most lactic acid is removed after exercise and isn’t to blame for soreness. It isn’t useless either; it contains a fuel source for high-intensity running. With the right training, we can delay the onset of lactic acid accumulation and improve our body’s capacity to use it for fuel.

So what is lactic acid? It is a by-product that’s created when we burn glycogen without oxygen as we run. The higher the intensity of the run, the more lactic acid we create. In the blood, it breaks down into lactate and hydrogen ions. The lactate gets processed and converted into fuel by mitochondria – the energy factories in our cells. It’s those hydrogen ions that cause all the trouble.

When hydrogen ions accumulate, it becomes difficult for the muscles to contract. This makes running feel more strenuous and causes the burning feeling we feel after a hard workout. Fortunately, we can train our bodies to become better at buffering hydrogen ions and delay the time it takes for that burning to set in. Running beyond our lactate threshold - the intensity at which lactic acid begins to accumulate - trains the body to become better at using lactic acid as a fuel.

A study at the University of Western Australia found that athletes who worked out at 120-140% of lactate threshold three days a week for five weeks improved their ability to buffer hydrogen ions by 25%. Athletes who worked at 95% of lactate threshold saw no improvement.

By running beyond your lactic acid threshold, you can train your body to more efficiently process it into a fuel, and improve your capacity to buffer hydrogen ions. All of which helps you run faster, for longer.