There is a school of thought, popularised by Professor Tim Noakes of the Sports Science Institute of South Africa, that maintains it’s impossible to reach your body’s absolute limit.

“Your body won’t allow you to push beyond a certain level,” agrees Dr Thomas W. Rowland, author of The Athlete’s Clock (R188, loot.co.za), a book that explores all aspects of peak performance. “Eventually, you shut down.”

Dr Rowland uses an example of a treadmill stress test to make his point. It goes something like this: a technician hooks up electrodes to your chest and tells you to start walking on the treadmill. The slope becomes steeper and the pace faster in three-minute increments. At some point you have to start running. And then you run until one of three things happens: he stops the test because he’s detected a problem with your heart; he ends the test when you have hit a target heart rate; or you give up.

In the “you give up” scenario, imagine that your doctor offers you R10-million to keep going another minute. “You’d do it,” Dr Rowland says. “You could go beyond what your brain has told you to do.”

You still wouldn’t run so hard that you’d hurt yourself, but you would find a way to earn that R10-million. I would have stuck around if the doctor offered me R10-million. Hell, I’d even throw a vital organ in there for good measure for that amount of money. Absent of any kind of incentive, I’d get off at the first stop.

University of Texas exercise scientist Dr Ed Coyle agrees, but only if we’re talking about untrained individuals. The higher the level of training and experience an athlete has, the closer he or she can push toward that limit.

“A lot of times with athletes, you can see they’re doing all they can just to stay upright,” Coyle says. “I don’t think even a million dollars would make a difference.”