Q: I just completed my first marathon with the goal of running at as comfortable a pace as possible. I wore my heart rate monitor to record my times for each mile, and I was surprised to see that my heart rate was almost exactly the same at the beginning of the race as it was at the end. I know that with long events heart rate tends to drift up, but why doesn't it appear to have happened here? Should I have pushed harder at the end? - J.H., Davis, CA

A: If environmental conditions that impact performance (like air temperature, hills and wind early and late in the race) didn't change drastically during the marathon, your response is indeed unusual. As you say, heart rate generally drifts up during a long event like the marathon if pace stays the same. Or, if heart rate stays the same for the duration, it's usually because pace has slowed. The fact that both of your readings remained steady throughout may reveal that your aerobic fitness was excellent, you stayed well hydrated and nourished and you ran well within your ability. In other words, you trained and raced very well, especially for your first marathon. It also means that you may very well be able to go somewhat faster in your next one.

Source: fitlinxx.com