The term perception of effort refers to a person’s subjective sense of how hard he or she is working relative to his or her limit during exercise. Distinct from pain, thirst, heat, fatigue, and other perceptions that are commonly experienced during exercise, perception of effort plays a critical role in running performance. The better you get at judging how close you are to your limit at an given moment in a race, the closer you will come to finishing each race in the least amount of time physically possible. No device, test, or calculator can do that for you; it must be done by feel.

Experience is the best teacher of perceived effort. Studies have shown that a runner’s (or other endurance athlete’s) ability to judge his or her effort naturally improves with experience, resulting in better performance independent of changes in fitness. A 2017 study by Australian researchers, for example, found that performance in a series of 20 km cycling time trials improved and became less variable with each repetition in a group of recreationally active adults who’d never done a time trial before.

You can put experience to better use and accelerate this learning process by taking active measures to refine your perception of effort in training. One such measure is a type of workout that I call stretch intervals. I learned the workout from Coach Ben Rosario who uses it when training his HOKA Northern Arizona Elite squad, including Scott Fauble who placed 7th in this year’s Boston Marathon.

Sara Vaughn trail training
photo: 101 Degrees West

The basic concept is very simple: You run a number of fast efforts of a certain duration, and try to cover a little more distance with each effort. Obviously, you can’t run the first interval all-out and hope to go farther in subsequent ones. But neither should you jog the first one in order to make it easy to cover more distance each time. When the workout is properly executed, the first interval is hard, you go just a few yards further in each of the following intervals, and the last one is an all-out effort.

Besides providing a solid dose of fitness-boosting high intensity, stretch intervals improve effort perception by challenging you to pay very close attention—and make very fine adjustments—to it. The more repetitions you do, the closer together each level of effort is and greater the challenge becomes.

Thus, if you’re a newbie or just not very good at pacing, you’ll want to start with a handful of somewhat longer intervals. Four times four minutes might be an example, following the same pattern of running the first interval at a speed that leaves just enough room to build up to an all-out effort in the last interval. If you’re a master pacer, you can do as many as 10 or 12 shorter intervals. There are endless possible variations on the theme, but Rosario likes to have his athletes do stretch intervals uphill because that final, all-out effort isn’t as hard on the body when performed on a slope.

stretch intervals Sara Vaughn
photo: 101 Degrees West

The Workout

Before you head out the door, choose two items to carry with you and use as markers during the session—a pair of brightly colored socks work well. Warm up with one to three miles of easy jogging, a few drills (e.g. skips, high knees, butt kicks), and a handful of short, relaxed sprints (a.k.a. strides).

The main section of this version of stretch intervals consists of seven times one minute hard up a moderately pitched incline with a very slow jog back down the hill to your starting point. Run the first interval at a speed that, according to your perception of effort, leaves you just enough room to increase your effort six notches more in the remaining intervals. After one minute has elapsed, drop a marker, slow down, and give yourself about two minutes to return to your starting point.

Run the next interval just a teensy bit faster, drop the second marker, and pick up the first on your way back. Continue in this fashion until you’ve completed all seven intervals, the last of which should be an all-out effort. After catching your breath, cool down with another one to three miles of jogging.

Don’t beat yourself up if you botch the workout by failing to cover more distance in one or more reps. Just try again in a week or two. You will get better over time, and that’s the whole point!