Don't stray too far from intervals

During the final 10 weeks of the investigation, the runners, whose average 10k times ranged from about 34 to 42 minutes, were divided into two groups. Members of one group carried out two Jack-Daniels-style 'tempo' workouts per week, which involved running for 29 continuous minutes at roughly lactate-threshold pace (the velocity above which blood lactate levels begin to skyrocket). For most runners, this pace is about 12 to 15 seconds per mile slower than 10k race pace

Members of the other group avoided lactate-threshold training and instead completed two interval workouts per week. These workouts consisted of either 200- or 400-metre intervals, which were conducted at about 10k to 5-K race pace or faster. About three total miles of interval running (24 200s or 12 400s) were covered per workout. Aside from this difference (intervals vs. tempo runs), the training schedules of the two groups were identical and consisted of medium to long, moderately paced runs

At the end of the study, the runners were tested during 800-metre and 10k competitions. It doesn't take a rocket scientist to reckon who fared better in the 800: interval-trained runners improved their 800-metre times by an average of 11.2 seconds, while threshold-trained athletes inched upward by just 6.6 seconds. The interval trainees had trained at faster paces than the threshold individuals. The interval runners' training paces had been much closer to 800-metre speed. After several weeks of training, the interval trainees were simply faster than the threshold people and therefore could sustain higher velocities during an 800-metre effort

What about the 10K?
Since the threshold run is considered a hallmark of 10k training, didn't the threshold-trained runners do better than the interval people during the 10k competitions? Well, no. The thresholders boosted their 10k clockings by 1.1 minute, but interval runners improved their times by a full 2.1 minutes! That spelled about a 10-second per mile advantage for the interval runners!
Why was interval training superior? Well, setting a new PB in the 10K is in one sense not that much different from reaching a new record in the 800: to do either, you have to be able to run more quickly. The interval trainees trained faster than the threshold people and thereby developed better economy, coordination, and comfort while running fast. All of that translated into higher-speed 10k running

- pponline, Owen Anderson

MY COMMENTS: After a couple of weeks off from intervals, I went back to the the track today for 6 x 800- 2:54, 2:52, and the rest 2:48. I am right about where I left off. It might be time to look for another race!