There are lots of running-related techniques and methods that are widely known to be effective but that achieve their effects in different ways than most runners believe or assume. For example, drinking water and consuming carbohydrate during endurance exercise are known to enhance performance and are believed to achieve this effect by limiting dehydration and supplying energy to the muscles, respectively, but in fact drinking water enhances endurance performance by reducing the sensation of thirst and consuming carbohydrate does so by acting directly on the brain in a manner that reduces perceived effort. Actually, I lied: these two measures enhance endurance performance in all of the above ways, water by limiting dehydration and reducing thirst and carbohydrate by supplying energy and reducing perceived effort, but you get my point.

Here are three more interesting examples of techniques and methods that don’t work entirely the way most runners think they do.

High Intensity

Science has supplied iron-clad proof that high-intensity exercise is an essential ingredient of any program intended to optimize endurance running performance. Although high-intensity work should account for only a small fraction of a runner’s total training time, it is impossible to achieve the same level of competitive performance without it.

Why? Most runners believe or assume that high-intensity exercise complements low-intensity exercise via purely physical mechanisms, such as increasing aerobic capacity and lactate tolerance. And it does. But research suggests that the most important difference between high intensity and low intensity may be psychological.

In a 2017 study, British scientists divided 20 healthy volunteers into two groups. For six weeks, one group engaged in an exercise program consisting entirely of high-intensity interval workouts (HIIT) while the other group did an equal volume of exercise exclusively at low intensity. Testing performed both before and after this six-week intervention revealed that although the two exercise programs resulted in roughly equal changes in aerobic fitness markers, members of the high-intensity group exhibited significantly greater improvement in a time-to-exhaustion test and, separately, in a test of pain tolerance.

The researchers concluded, “The repeated exposure to a high-intensity training stimulus increases muscle pain tolerance, which is independent of the improvements in aerobic fitness induced by endurance training, and may contribute to the increase in high-intensity exercise tolerancefollowing HIIT.”

Depletion Workouts

A depletion workout is a workout undertaken without any carbohydrate intake either before or during. For example, you might run 16 miles first thing in the morning on no breakfast and consuming only water as you go. Most runners who are familiar with this practice believe its intent is to enhance the fat-burning capacity of the muscles.

Again, this is true but not the whole story. Although studies have shown that depletion workouts enhance the fat-burning capacity of the muscles, this effect has not been linked to any performance benefit. But other research has demonstrated that the specific stress imposed by training in a low-glycogen state upregulates certain genes involved in mitochondrial biogenesis, and this adaptation does increase endurance performance. In plan English, depletion workouts add horsepower to the body’s aerobic engine. That’s why high-intensity interval sessions, in which glycogen and glucose supply almost all of working muscles’ energy—even when they are done in a carb-restricted state—work just as well as long endurance sessions as depletion workouts.

Plyometrics

Plyometrics is a form of training that consists of various jumping exercises such as hopping up into a box on one foot. It tests an athlete’s ability to produce power, or rapid application of force, and for this reason it is widely believed that the purpose of doing plyometrics as a runner is to increase stride power.

This is true for sprinters but not so much for long-distance runners. In distance runners, plyometrics training has been shown to enhance stride stiffnessand thereby increase running economy. The type of stiffness I am referring to is the type that physicists talk about in relation to springs. The human body functions as a sort of spring during running, and just as a pogo stick with a stiff spring will bounce higher than a pogo stick with a loose spring, a runner with greater leg stiffness is able to capture more of the “free energy” that rebounds from the ground into the foot after impact and use it to propel forward motion.

Certain plyometrics exercises, including the drop jump, which entails stepping off a box and landing on the floor below, increase legs stiffness without increasing leg power. The fact that they, too, enhance running economy shows that, for distance runners, plyometrics really is about enhancing stiffness, not power.