To the Line!

As Fast Friend gets out of the saddle on the approach to the county line, you don’t want to start your chase too early. In a sprint “you recruit mostly fast-twitch muscle fibers, which can generate a lot of power but don’t last long,” says Sternlicht. “You’ve got about 10 to 12 seconds of max effort.”

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In an all-out sprint, you’re not accessing stored energy for fuel, but instead gobbling up the immediate fuel that exists in the muscle. When it’s gone (which takes a matter of seconds), you’re toast.

The good news is that a single 10-second sprint won’t kill your legs for the rest of the ride. The same processes that allowed you to rally after that big climb will help you recover on the fly, and the more you’ve trained, the faster you’ll bounce back. You’ll probably get an adrenaline rush too; to maximize uptake of the chemical, Sims suggests pedaling easy for a moment after you feel that surge of “Go!” juice.

If the sprint didn’t go as planned, don’t sweat it. “I tell my athletes, 'The negativity monster is always lurking, but you can make a conscious decision to not go there,’” says Day. Just thinking negative thoughts can zap your muscular strength, although scientists still don’t completely know why, she says.

So the second you feel doubts about your abilities, shift your focus to things you can control: Can you hydrate? Take in fuel? Sit on a friend’s wheel for a few minutes?

Next, break up your ride into digestible bites. Say, “I know I can make it two more miles,” then reevaluate at that point, says Day. Almost always you’ll find yourself feeling better and ready to go a little longer.