Want to get faster without adding intensity and mileage? Try this simple trick: relax your face.

When you see a photo of yourself running, does it look like you are in agony? It turns out that being too tight (especially the facial grimace) can slow you down. Tightness throughout the body often originates from your face.

Tensing up in the face signals all the other muscles that they should also tense. Each muscle group must then work harder, fighting through the counterproductive tension to perform the intended movement of propulsion. Tension in your upper body and face can result in stiff arm movement, tight shoulders, and tied-up legs. More exertion tires you out more easily.

Therefore, the secret to faster, smoother running is to concentrate on relaxing, particularly your facial muscles. World-class sprinters know this secret. Typically, their legs and arms are frenetically pumping while their faces and shoulders look completely relaxed.

What works in sprinting also works in distance running. To avoid tightening up, keep your face loose and relax your neck and jaw. Clenching your jaw expends extra energy and inhibits your oxygen intake. To relax your jaw, try opening and closing your mouth, yawning, or exhaling a long, slow breath. Facial muscles control the degree of tension in your entire body. Therefore, if you concentrate on relaxing your jaw and facial muscles, your entire body should relax.

At the end of a race, even if you have been running relaxed, it is likely that you will tense up as you kick to the finish. This is exactly when you need to focus on relaxing your eyes and jaw muscles. If you are racing in bright sunlight, it can be a good idea to wear sunglasses to avoid squinting, which can tense up the eyes and face and can lead to tightening up. This is one of the reasons why you often see elite runners donning sunglasses during races.

It turns out that the easiest way to relax your face is to smile. Perhaps the best way to relax and run to your potential is to remember that you are doing this for fun. If you smile like “ridiculously photogenic guy,” you should be well on your way to running faster by relaxing.