The new Nike Vapor Fly shoes improve running economy 4% what does that mean?
Updated: Feb 3, 2018
On November the 6th Wouter Hoogkamer, Shalaya Kip, Jesse, H. Frank, Emily M. Farina, Geng Luo and Rodger Kram published an article establishing the new Nike vapor fly shoes as 4% faster in average for a group of runners (https://link.springer.com/article/10.1007/s40279-017-0811-2).
But what does a 4% improvement in running economy really mean for an average runner?
Well when I compared Trail shoes (heavy and slow) vs the new Nike 4% shoes I see an apparent improvement in my running of 13 watts at the same effort level (Heart rate) in other words 13 seconds per kilometer or about 4.8%. In this n=1 experiment the Nike 4% claim is supported. I will be lacing them up for my local 10k race on Sunday!