Take the guesswork out of determing your best target pace for races and workouts.
There’s a very simple way of telling how fast you should run on long runs, and what you are currently capable of running in races. It’s a one-mile time trial that is inserted into one of your shorter runs, about every two weeks. This can help you set realistic goals for races so that you won’t start too fast. This “magic mile” will also tell you very accurately what you should be running on long runs.
For more than a decade, I’ve analyzed how much runners slow down when they go from a fast one mile to an average mile in a hard 5K, 10K, half marathon, and marathon. After looking at thousands of computations, the numbers speak for themselves. The full explanation is in my books Year-Round Plan, Half Marathon and Galloway Training, but here are the key points:
Galloway’s Prediction Formula:
Take your one-mile time trial time and adjust to find a potential fast pace for you, in each race:
5K—add 33 seconds
10K—multiply by 1.15
half marathon—multiply by 1.2
marathon—multiply by 1.3
Example: You ran a fast (for you) one-mile time trial and the time was 10:00. In this case, 10:33/mile is your current potential for a very hard pace in a 5K; 11:30/mile is your current potential for a very hard pace in a 10K;
12:00/mile is your current potential for a very hard pace in a half marathon;
13:00/mile is your current potential for a very hard pace in a marathon.
To determine your long run pace, add two minutes to the predicted marathon pace. In this case it would be 15:00/mile.