Myth of the “20 Miler”

As we head into Fall, goal marathon races are right around the corner. In St. Louis the first one up is Oct. 6. Of course, Chicago is Oct. 13, New York Nov. 3 and Indy Nov. 9.

It’s around this time that a lot of runners believe they have to get in their “20 miler” leading into their goal marathon. For some, and I mean a small group, this is fine. They have prepared well, it fits into their training plan and are able to complete it within the time necessary to avoid muscle tissue damage, which takes weeks to recover from. For others it’s the workout that leads to injury, sickness, under performance and sometimes inhibits the runner from even hitting the starting line of their goal race.

So, who should be doing 20 milers and when? The litmus test is can you complete it in less than 2 hour 30 minutes or 9:00 per mile. If yes you are good to go. For when to do it, well under the Lydiard Training method, our runners complete their runs of longest duration, back in weeks 12-14 of aerobic base building during a 24-week plan. For some this includes a few 20 milers, for many it does not. Subsequent weeks are spent developing other important physiological systems such as strengthening using hills, anaerobic using intervals and sharpening using integration and tapering.

However, the simple answer is doing a 20 miler for those who can complete it in less than 2:30 at least 4 weeks out from goal race is workable. Anything closer jeopardizes fitness, may cause breakdown, sickness or even injury. The slower the runner the more time it will take, more pounding on the legs creating more physical stress which is impossible to recover from only 4 weeks out from goal race.

Dr. Jack Daniels, world reknown exercise physiologist and one of the best marathon coaches around, recommends long runs be capped at 2:30 to 3:00 hours max. He says running longer than that offers high risk of injury and burnout. See his famous explanation of this on the video link here. It's a classic and simplifies they "why" behind the science.

So how should slower runners handle this? Their training should be comprehensive meaning the day before their 2.5 hour run, they should be doing a slow aerobic run of an hour or so or under Lydiard they would be doing something of up-tempo pace called an Out/Back or Progress Calibration Run. Then within a 24-hour period they have covered 3:30, more than 15 miles most likely, haven’t damaged their legs and can properly recover. If you have a coach telling you to go out there and run the “20” and you can’t get it done in less than 2:30 ask them why, what is the benefit and how are you going to recover from this without injury. Ask about the science behind their pushing you to do this. I can tell you its not there.

Here at Running Niche we are trained Lydiard level I & II coaches. Please stop in the store to learn more about the Lydiard Method. We can help you sign up. While your personalized plan costs $100, and goes to a non-profit, we provide the day to day coaching at no additional charge.

Bob Dyer (Co-owner, Running Niche)
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