Chris Twiggs, International Program Director, Galloway Training Programs writes:
While we call our predictor of race performance the "magic mile," there is not only magic in Jeff Galloway's method. In fact, there is a great deal of research behind the recommendations for pace and run/walk ratio. Over a million runners and walkers have followed Jeff's training recommendations, and he has received feedback from more than 350,000 people. What he has learned from that feedback is that runners who extend the running portion of their run/walk beyond 4 minutes or extend their walking portion beyond 1 minute tend to experience diminishing returns. As a result, our recommendations start with the 4:00/1:00 recommendation for 4 hour marathons and include less running for times slower than 4 hours and less walking for times faster than 4 hours. This recommendation holds true for everything up to about 3 hours in the marathon, at which point we take other factors into consideration to fine-tune the ratios for those fasties.
Now, these recommendations are just that - recommendations. They are not laws, rules, or orders. You may ultimately find that your perfect blend of run/walk is a little different from what we suggest for your pace.
First, visit http://www.jeffgalloway.com/training/magic-mile/ and plug your Magic Mile time into the calculator. If you haven't run a Magic Mile yet, instructions for doing so are included on that page.
After plugging in your MM time, look at the predicted pace for the distance event you are training for. Then look at the bottom of the page to see the recommended run/walk ratio that pace. Note that training pace and ratio will be different from the actual race pace and ratio.
Finally, use the recommended ratio in some of your training runs and see how you feel. After a few runs, play around with the ratio to see if anything feels better. Try cutting the times in half (going from 4:00/1:00 to 2:00/0:30, for example) or reducing the running time by a few seconds to see if anything feels easier or helps you recover faster.
The bottom line is that we want you to be successful in reaching your goals without injury so that you can enjoy a lifetime of running and walking.
Best wishes for all the runs ahead,