When many runners think of a “fast” shoe, they immediately think of a shoe that is lightweight. It seems logical – the lighter the shoe, the easier it is for your legs to pick it up on every stride. However, lighter does not always equal faster.
The Boston Globe has a good article on what a “fast running shoe” actually means. Surprisingly, a lighter shoe with less cushion can actually mean slower times for a runner in a long race (I.e. marathon).
We need the full shock absorbing benefit of a traditional shoe for a marathon. Studies show that for every 100 grams (just over 3 ounces) of reduced weight in a pair of shoes, a runner will only gain 1 to 2 percent improvement (measured in time and oxygen efficiency).
If you’re an advanced or elite athlete, that
improvement can make all the difference in the world. But if you’re a 4 hour marathoner, you will likely only gain a 2-5 minute improvement in time, while forcing your body to endure 20 percent more stress due to the reduced level of shock absorption.
The fact that a shoe is easier for your leg to lift during a stride does not always mean that it is giving the muscles a break. In order to ensure that a shoe helps you run faster, it is far more important to choose a shoe that that has the appropriate amount of support for your specific biomechanics.
Do the benefits of extra cushion mean that minimalist shoes are a bad idea
Not necessarily. It is important to note that are talking about speed here, not injuries. For some runners, a heavily cushioned shoe can weaken foot muscles and potentially cause injury. That is one of the main selling points for minimalism.
However, all things being equal, you should not assume that a lighter weight marathon shoe is always faster.