When your brain tells you you’re done, it turns out you’re not. Just like in a car, it’s a conservative safety measure designed to make sure you always have something left, even when you think you don’t. If you’ve ever worked out, you’ve probably experienced this. If you can quiet the mind, you can always do a few more reps. Sometimes people on drugs chemically turn off the safety valve and exhibit superhuman strength.
Jad Abumrad and Robert Krulwich from WNYC’s marvellous Radio Lab explored this in their recent show “Limits“. From the transformational tale of Julie Moss, who collapsed at the finish line of the Hawaii Ironman in 1982 (you’ll probably remember the video). The voice in her head said “get up”. In their description of the amazing 3000 mile Race Across America, you’ll hear about what happens when the cyclists push through this safety valve. For example, a soldier in the race thinks he is being chased by Mujahideen and just takes off, sprinting like crazy. A fascinating piece of research found that cyclists directly injected with glucose into their muscles experienced no improvement in endurance, but if they swirled sports drink in their mouth and then spat it out, it tricked the brain into thinking more energy was coming, and the conservative empty signal was temporarily shut down resulting in an increase in endurance. (Perhaps related, in Born to Run , it describes Kalahari bushmen taking a tiny sip of water and swirling it in their mouths to revive themselves, rather than gulping it down.)
To me, this explains what ultrarunners do when they find a way to keep going. If you’re running for 8, 10, 12, 18, 24, 36, even 48 hours, you’re going to run out of steam at least once . Like the example of Scott Jurek, arguably the greatest ultranunner ever, 7 time champ of the premier 100 miler, Western States, lying down exhausted in the “world’s toughest foot race” the Badwater 135 mile race from Death valley to the portals at Mt Whitney. As retold in Born to Run, he was way behind the leader, he has a conversation with himself while lying on the ground, gets up, and somehow finds a way to not only keep going but to blow the competition away and win.
In my upcoming 50 miler, if I end up feeling like I can’t go on, I hope the voice in my head says “keep going” 🙂 At any rate, it’s handy to know my brain is just trying to trick me, and if I dig deep, should be able to tap into that reserve tank.