Training: Workouts

The Training Lab
Every runner knows speedwork makes you faster. But how long should you run? How hard? And how much recovery do you need? Recently, researchers designed a study to see which of these variables elicited the greatest physiological response
        by: Ed Eyestone  


The Finding: A short recovery makes for a harder workout

Every runner knows speedwork makes you faster. But how long should you run? How hard? And how much recovery do you need? Recently, researchers designed a study to see which of these variables elicited the greatest physiological response (that is to say, which tuckered out the athletes the most). As it turns out, the most significant variable was the length of recovery.

The researchers had subjects do 15 intervals on an exercise bike at different intensities, for different lengths of time, and with different lengths of recovery in between. No big surprise that the hardest workout was the one with the longest work intervals (40 seconds), performed at the highest intensity (a pace equivalent to mile-race pace), with the shortest recovery between intervals (20 seconds).

The surprise came with the second-hardest workout. The work interval and the recovery were the same, but the intensity was lower, which should have made the workout easier. It wasn't, because the recovery was so brief. But does that mean you should always keep your recovery short? Not necessarily.

If you're new to speedwork, or you have a hard time hitting your race paces during your speed training, keep your recovery periods longer--more than half the length of your work interval. So if you run 800-meter repeats in four minutes, make your recovery jogs about two-and-a-half minutes. The extra time you allow between work interval? will help you recover enough so that you're able to hit your race paces.

If you've been doing speedwork regularly, and you can consistently hit your race paces, consider shortening your recovery periods to boost intensity. Start by cutting your recovery in small increments. Let's say you've been running 400-meter repeats at 10-K race pace with 90-second recovery periods. Over a number of weeks, cut the length of your recovery by 5 to 10 seconds at a time until you can complete the workout at the same pace with just 60 seconds of recovery, or about half the length of your work interval.

Ed Eyestone has a master's degree in exercise physiology