By: Sarah Schmermund, M.A.

Historically, research has focused on the physical body (muscles, heart, and lungs) to attempt to figure out what limits a person’s physical exertion capacity. Do tired muscles just give out at a certain point, dictating how fast we can run (or swim or cycle or row)? Recently, however, researchers have shifted their attention upward, towards the brain. Professional athletes have long asserted that their brains play the most pivotal role in their performance, and researchers now think they may be on to something. Is there something more influential on our athletic performance than our muscle composition and lung capacity?

In a recent experiment, Dr. Thompson, head of sport and exercise science at Northumbrian University in England, was determined to find out.? He wondered whether competitive cyclists really were riding as fast as they physically could. He instructed the bicyclists to pedal as fast as possible for 4,000 meters. He collected their times over a number of sessions, establishing a baseline for what the cyclists thought was their limit. The cyclists were then asked to bike the same 4,000 meters again, this time in a race against an avatar figure of a cyclist on a computer screen in front of them. Each cyclist was shown two avatars, one representing his opponent and one representing himself, as it moved at the rate he was actually pedaling. The cyclists were told the competing avatar would be moving at the pace of the cyclists best effort from the previous cycling sessions, but in actuality, the avatar was set to ride 1% faster than the cyclist ever had. Thinking they were racing against their own best time, the cyclists ended up matching the pace of the competing avatar, pedaling faster and harder than they had ever before. Though a 1% increase in speed doesn’t sound like a lot, in the world of competitive sports, 1% can mean the difference between 1st or 2nd place (or not placing at all).

To better determine what an athlete’s actual limit is, Dr. Thompson conducted the experiment again, this time with two conditions. The first would be told they were racing against an avatar going 2 or 5% harder than their best pace. The second would again be deceived, told the avatar was moving at their best pace while it was actually going 2 or 5% harder. The first group of cyclists gave up from the start of the competition and performed only at their best pace. The second group worked harder and kept up with the avatar programmed to go 2% harder than their best time. 5% harder, though, was apparently too much; the cyclists kept pace for about half the race, but then ultimately gave up.


Dr. Thompson attributes this phenomenon to the brain and the athlete’s belief system. The brain usually conserves the body’s limited energy stores, not allowing an athlete to work too hard. When faced with competition, though, the brain appears to allow the athlete to access this muscle fuel more deeply. If an athlete believes a certain pace is possible, it appears he can tap into the reserved energy stores for the sake of competition. At small intervals, deceiving an athlete about what his “best” is may allow him to push the barrier to achieve a new personal best.

While you may not be a professional athlete, utilizing a little deception may allow you to also reach a new personal best when you’ve reached a performance plateau. Let a friend or trainer time your run but have them tell you your pace is slightly faster than it actually is, or have them count your reps and report your number as slightly higher. The key word here is slight; a small percentage better is all you need (remember the cyclists: 2% was doable, 5% was not). The next time you hit the treadmill or start a round of squats, you’ll be competing against a faster, stronger version of yourself. And as long as you believe you can do it, your brain will allow your body the energy it needs to hit those improved numbers.

Kolata, G. (2011). A little deception helps push athletes to the limit. The New York Times. Retrieved from: