To help my runners determine their best half-marathon pace, I created the McMillan Running Calculator. Photo: Mitchell Leff/Getty Images Step #1: Use Calculators & Calculations That’s why having a good estimate of goal pace and then practicing it in training is an absolute requirement to be ready for your best performance on race day. Since half-marathon pace falls somewhere between those two thresholds for most of us, it makes it a hard pace to “feel.” Running close a threshold is much easier for most runners.

The lactate threshold is roughly one-hour race pace (half-marathon pace for really speedy runners, but too fast for most) whereas the aerobic threshold is roughly two and a half hour race pace (half-marathon pace for some of us, but a bit slow for many-and marathon pace for a few up front).

Part of the reason that half-marathon pace is such a weird pace for many runners is that it lies between two key thresholds: The anaerobic or lactate threshold and the aerobic threshold. Hold back too much and you’ll finish fine, but may be kicking yourself as you realize how much you have left in the last three miles. A bit too fast and those wheels fall off somewhere in the middle, leaving you to slog some hard miles to the finish. Nail your pace, and the half marathon can be the most satisfying of races, run at a fast-but-fun level of effort that makes you feel invincible and amazed that you can hold it for so long.

You hear lots of phrases used to describe half-marathon pace but let’s discuss some specific ways to determine your best half-marathon race pace-and then how to confirm that the pace is possible on race day.

Download average half marathon pace