As a longtime running coach and Olympian Jeff Galloway needed a way to predict race performance for his clients (with appropriate training) for multiple distances, he did some research. Galloway spent a decade trying different formulas and using data from athletes he worked with, as well as his many coaching programs and running retreats, and discovered that the most accurate predictions came from using a one-mile time trial . Galloway calls this training the magic mile (MM).
Data from a simple 1 mile time trial can be used to accurately predict the deceleration experienced over distance in a 5K, 10K, half marathon and marathon. It can also be a great tool to monitor progress during workouts. Here’s how to run your own MM and how you can use it to predict your own performance on an ideal race day.
Galloway suggests doing an MM roughly every two weeks to monitor progress and get the most accurate mileage reading at the end of your season. If you don’t care about specifics and just want a good assessment of your skills, it’s also okay to include one in your training schedule when you get curious (just schedule it for a day when you’re fresh, well rested have legs). .
A track is the easiest way to measure your MM, although GPS data and a stretch of flat road works well too). If you decide to go down the road, make sure to measure your distance several times before doing your MM accuracy counts in this calculation.
Warm up with 10 minutes of very easy running, followed by a few accelerations to get your legs ready for a fast mile run (one mile of a standard 400-meter course is four laps on the inside lane).
Go as evenly as possible on each 400-meter stretch. If you can, record how fast you ran each quarter mile, or review your data later for future comparison. Be careful not to take off too much at the start – run around as fast as you can at a steady pace for a mile without straining to the point where you feel like you’re about to throw up. At the end of the mile, you should feel like you couldn’t go more than a few hundred yards more at this pace.
Cool off by jogging or walking for 10-15 minutes.
How to count
You can use the Magic Mile Calculator on Jeff Galloway’s website to calculate your training and race pace based on your MM time. If you use min/km for training, you can adjust the pace by dividing by 1.6.
The calculation uses the following formula for pace in miles (we also added kilometers):
Add 33 seconds to your magic mile for the 5k pace (in miles). To calculate 5k pace in min/km, divide your Magic Mile time by 1.6 and add 21 seconds.
Multiply your Magic Miles time by 1.15 for 10k pace (per mile) or by 0.71 for min/km
Multiply your Magic Mile time by 1.175 for 10 miles (16 km) pace or by 0.73 for min/km
Multiply your Magic Mile time by 1.2 for half marathon pace or by 0.75 for min/km
Multiply your Magic Mile time by 1.3 for marathon pace or by 0.81 for min/km