You may not realize it, but you probably hold back when you set out on a hilly run.
So-called anticipatory pace conservation is a protective mechanism in the brain. In a study in Medicine & Science in Sports & Exercise, a group of trained runners did a 3,000-meter treadmill drill. Half of them were told that the last 800 meters would be hilly. For the other group, the steep incline came as a surprise.
The first group ran the easy part almost 14 seconds slower. This may not sound like a lot, but for nonpro runners, the difference may be even greater.
The takeaway: Mix up routes, and try to keep pacing during flatter portions. And to conquer tougher hilly courses, breathe and relax, which improves energy efficiency.