PUBLISHED 07/02/2007
Unless you're in high school or college, you probably haven't raced a mile in a while (or ever, for that matter). So what do you do when speed workouts call for intervals at "mile race pace"? You could simply guess, but you risk running the intervals too fast--or too slow--and not reaping the appropriate training benefits. You could use the Eyestone Method of predicting pace, which involves actually lacing up your racing flats and running a very hard mile--certainly the most accurate way of assessing current ability, but also a lot of work. Or you can take any of your current race times at any standard distance and use the clever and remarkably accurate Four-Second Rule.
The Four-Second Rule was developed by British distance coach Frank Horwill, who observed that most runners' paces per every 400 meters will increase by about four seconds as they move up from one "classic" race distance to the next. For example, a runner who races a 10-K in 40:00 clocks 96 seconds for every 400 meters. In the half-marathon (the next classic distance), he can expect his 400-meter pace to be about 100 seconds. Based on your finishing time for any race distance from the quarter mile to the marathon, you can figure out approximate 400-meter times for any race in between, which helps you determine how fast you should run your speed workouts.
All levels of runners can use the Four-Second Rule, although elites may have less than four seconds' difference in their 400-meter paces. Of course, like any predictive model, the Four-Second Rule gives you only a good estimate of what your pace and performance times could be. And as you move more than one or two race distances away from your best event, the predictions may become slightly less accurate.
Once you've figured out your own pace chart based on the Four-Second Rule, here's how to work some of those paces into your training:
For Marathon Training: Take your predicted marathon pace and do an eight- to 12-mile run every two or three weeks to help you become biomechanically comfortable running at an appropriate speed for 26.2 miles.
For Tempo Runs: The "comfortably hard" effort of a tempo run can be difficult to quantify. So try doing your tempo runs at half-marathon race pace. Do one 20- to 30-minute tempo run per week to improve running efficiency.
For Long Intervals: Use your 5-K race pace for long intervals of 1000 meters to a mile. After each repeat, jog slowly for no more than the time it takes to run the repeat.
For Short Intervals: To build speed, try your quarter-mile repeats, such as 8 to 10 x 400 meters, at mile race pace with 90-second recovery.
For Supershort Intervals: Aim to run very short repeats, such as 8 x 200 meters, at about 400- to 800-meter race pace. Your recovery between each repeat should be up to five times as long as it takes you to run the repeat.
WE DID THE MATH
Here's how the four-second rule plays out...
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