The Wall is every runner’s torment.When will I hit it? Will I recover? How?

Even an elite, consistent runner like Ellie, isn’t impervious to The Wall. At around mile 21 (35k), Ellie’s pace drops slightly as her Flight Ratio (an efficiency indicator) continues its slow downward trend (it’s fortunate that Ellie starts at elite levels!). But what is interesting is how she is able to change and adapt. By moving from a heel/mid footstrike to a solid midfoot strike, Ellie subtly changes her stride to maintain her goal pace.

The wall comes earlier for some. Fatigued Fred was shooting for 3:50, but things begin to fall apart around the 30k mark, where his pace drops from a solid 9.5 min/mile to 11 min/mile. He ultimately finished in 4:24, unable to make the changes needed to get back on track.

We see a steady decline in Fred’s Flight Ratio – from 15% early in the race, ultimately down below 0% when he’s forced to walk (a negative flight ratio occurs when both feet are on the ground at the same time.

Next up…The Finish!