I have been coaching Kathy for over 20 months now in my Ecoaching program.  She has improved her marathon time from 5:15 to 4:38 as she has reduced the run-walk-run ratio from (run 3 minutes/walk 1 minute) to (run 30 seconds/walk 30 seconds).  Kathy's quote: "Definitely less fatigue, less aches, pains and injuries, and I ENJOY running faster which I wasn't able to do with the 3 minute/1 minute ratio." 
 
Kathy's success has prompted me to suggest shorter amounts of running for other clients, which has also helped them improve times, usually while feeling stronger at the end. 

Ecoach client Terry improved his marathon PR by 25 minutes when he shifted from a 30/30 to a (run 20 seconds/walk 40 seconds) last year. 

These are not isolated cases. I have been inspired to use similar ratios in the marathons that I run with my wife Barbara. 

In the Breast Cancer Marathon (26.2 with Donna in Jacksonville) on February 21, Barbara and I were running with our friend Dr. Ruth Parker using a 1-1 until about 21 miles.  Barbara was feeling a minor pain in the hip and was slowing down during the second half of our one minute run, so I shifted to 30/30.  We speeded up about a minute a mile during the final 5 miles which included an on-ramp to a highway, and a significant bridge (i.e. two hills). 
 
Not everyone can run faster when they shorten the running segment, but practically everyone I've worked with on this issue reported feeling better: less fatigue, more finishing strength, quicker recovery – even when the pace was equal to the pace using a longer running segment. 
 
Walk breaks can empower each of us to take control over our fatigue and recovery – in advance.  Try different strategies and adjust when needed so that you are the one who is passing people at the end, feeling great, wanting to do it again.