The Role of Intervals in Marathon Training and Yasso 800’s

Every sound training plan has building blocks whereby each activity in succession should build on the one before with specific purpose. Anaerobic development, achieved through higher intensity, shorter duration interval sessions is an important part of your preparation for a half or full marathon, at the right time.

Phase 3 of the Lydiard pyramid, the Anaerobic Development phase, comes after a strong aerobic base has been built and preparation completed via the strength building hill training phase. Keep in mind that the half and full marathon distances are 98% aerobically based. Meaning if one hasn’t built a strong aerobic engine the benefits of which are ability to deliver oxygen to muscles, increased heart stroke volume, lowered resting pulse and higher working heart rate maintenance, through several weeks of slower, longer running, then you need to spend more time achieving this rather than moving into anaerobic development.

In the context of endurance training intervals are not “speed” training but are used for anaerobic development. They are bouts of work with a recovery generally equal to or shorter than the work bout. Lydiard said “there is a time for repetitions to develop anaerobically and depending on target race distance, sprint drills to develop fine speed. You have to organize repetitions and sprint drills at the right time so you can peak on your target day”.

For most marathoners/half marathoners doing intervals at above anaerobic threshold with enough recovery to repeat allowing the body to get used to high levels of acidosis is recommended. They should be prolonged harder work, not shorter durations. Distances of ¾ mile, mile, 1.5 miles and 2 miles are desirable. Under Lydiard these durations are done at ¼, ½ or ¾ effort, depending upon if the runner is early in the anaerobic phase or later in the phase. As an example, we have an athlete with capability of running a 3-hour marathon, about 7-minute pace per mile. During the interval phase these distances would be 7000 meters combined made up of several ¾ mile to mile intervals working from 6:15 pace down to 5:30 pace for each, with just enough rest to lower heart rate and get prepared for the next bout of work. Lydiard described these sessions as “tiring, exacting work”, but it gets the body used to being uncomfortable at faster sustained paces.

The picture below is a good example from my old training log as I was in the anaerobic phase preparing for a full marathon:

Bob Dyer Example Lydiard Training Log.JPG

In this example after a good warmup, I did 4x 1-mile intervals at about ½ to ¾ effort as I was later on in this phase, also rested a bit between with slower pace. Needless to say the next day was a recovery aerobic run.

Its key to remember that for longer distances, interval sessions should be done at distances longer than ¾ mile and stretch to up to 2 miles at ¼, ½ or ¾ effort depending on where one is during the training program. A final thought about the commonly implemented “Yasso 800”. First the idea that doing 10 repeat 800 meter runs at specific paces is reflective of your marathon target ie 3:00 minute 800 = 3:00 hour marathon, with equal rest, is not predictive of future race times, it is not scientifically validated.

Secondly it is found in the exercise physiology literature that for runners training for longer distances like the marathon that interval work is important but has to be done in proper sequence and distances building on a strong aerobic base and hill strength training. Doing them any earlier in the cycle can cause injuries and illness. If you feel you must do track or other high intensity workouts save them for a phase of training where you are ready for it, not early on. If you want to achieve your long race goals in the half or full marathon you need to work on your endurance, after all these long distances are 98%+ aerobic!

If you would like to learn more about the science and performance-based Lydiard Method, stop by the store. We are always happy to talk about your running!

Bob Dyer (Co-owner, Running Niche)
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