Miller suggests scheduling a predictor workout about three weeks before the big day. This will allow you to assess your current fitness without overtaxing your body too close to the race.
"You can't jump in and do this type of workout too early on in training either," Miller says. "It should be toward the end of the training phase when you've worked up to it."
More: 7 Running Experts on Effective Long-Run Training
As you're nearing race day, try working one of these predictor workouts into your schedule. Be sure to warm up beforehand and treat it like a race. By simulating race-day conditions, you're more likely to get an accurate pace.
Remember that these predictions won't hold up in extreme weather, during illness, or in the face of other extenuating circumstances. If the stars do align, however, these are paces you should be able to execute.
More: 4 Steps to Your Perfect Pace
Yasso 800s
Invented by well-known coach and Runner's World columnist Bart Yasso, this track workout is a favorite among marathoners and half-marathoners. Begin by taking your goal half marathon time and add about 8 minutes.For instance, if you hope to run a 2:00 half marathon, that would equal 2:08. Then multiply the number by two, giving you 4:16. While this time represents 4 hours and 16 minutes, for the purpose of this workout, you will consider it to be 4 minutes and 16 seconds. With that time in mind, you will go into the workout.
- Warm up 10 to 15 minutes
- 10x800 meters, completing each 800 in 4:16
- Take 4:16 of rest between each 800
- Cool down 10 to 15 minutes
If you can complete all 10 at 4:16 pace, you should be able to run that 2:00 half marathon. If you'd like to ease into this, consider completing several lead up workouts to calibrate pace, doing 4x800, 6x800, 8x800, and then 10x800. By the time you reach your final predictor workout three weeks from race day, you should have a good idea of what pace to run.