Adding anaerobic training to your regimen will increase speed and power while keeping you healthy.
Some runners have funny ideas about the meaning of the word “anaerobic”. It’s not their fault, though, because even many exercise physiologists harbor an outdated understanding of aerobic and anaerobic metabolism. Often I hear athletes talk about “going anaerobic” when their running intensity exceeds the anaerobic or lactate threshold, which is a moderately high but not extremely high intensity—one that most fit individuals can sustain for a full hour. This expression—“going anaerobic”—reflects an incorrect belief that the working muscles get their energy either entirely aerobically or entirely anaerobically, whereas in fact they almost always get their energy from both systems simultaneously, with the balance shifting gradually from aerobic toward anaerobic as exercise intensity increases. And indeed, exercise intensity must increase far above the lactate threshold before the muscles even get a majority of their energy anaerobically. If you were to run as far as you could in two minutes (in other words, as hard as you could for two minutes), your muscles would get about half of their energy aerobically during that effort.
This much is understood by most exercise scientists. But what all too many of these professionals don’t know is that most of what is classified as anaerobic metabolism is actually just incomplete aerobic metabolism. Recent research has shown that roughly 75 percent of the lactate that is produced through the anaerobic breakdown of glucose is further broken down aerobically within the muscles cells to release energy. The rest is shuttled to other organs and tissues, where it is either broken down aerobically to supply energy or converted back into glucose for future aerobic breakdown.
If anaerobic glycolysis is reclassified as incomplete aerobic glycolysis, as it should be, then virtually the only truly anaerobic metabolism that occurs in the muscles is the breakdown of high-energy phosphates. This type of metabolism becomes predominant only at the very highest exercise intensities, such as during 100-meter sprints.
While true anaerobic metabolism has only a tiny place in running, anaerobic fitness—or speed and power—is critical to distance running performance. The average runner thinks of factors such as VO2max, fat-burning capacity and running economy as being the keys to running performance and tends to forget about pure speed. But if you set aside your prejudices and look at the speed of world-class distance runners, you will see that pure speed is at least as important as the other performance keys. Most 2:11 marathoners are capable of running a sub-50-second 400m. Folks, that is flying!
Research confirms the importance of pure speed to distance running performance. A study by Finnish researchers found that 20m sprint times were nearly as powerful a predictor of 5,000m race times as VO2max. Studies by the same group have demonstrated that explosive power training effectively improves distance-running performance.
It may seem strange that anaerobic training enhances distance-running performance when there is virtually no anaerobic component to actual distance racing, but it’s true. The primary reason appears to be that anaerobic training increases the bounciness of the stride, so that the feet come off the ground faster and more forcefully. This improves running economy, because half of the energy that propels forward motion during running is supplied not by the body but by the force of impact, and the less time the feet are in contact with the ground, the less of that free energy is lost.
In short, for runners the point of performing types of training that involve anaerobic metabolism is not to developing anaerobic metabolic capacity but rather to increase the speed and power characteristics of the muscle fibers.
Therefore, true anaerobic efforts deserve a bigger place in your training than they have in your races. There are three specific types of anaerobic training that you should be sure to include in your training regimen: sprints, plyometrics and weightlifting.