The Nike Mayfly sought to achieve this through weight reduction. The more weight a runner is carrying, the more effort has to be expended to achieve the same result. The Mayfly eliminated any extra baggage. The parachute nylon upper and minimalist sole were as light as possible. The idea was that wearing the Mayfly in a race after training in your every day shoes would make your normal effort that much more effective. The original Mayfly’s innovation didn’t stop there. The shoe was designed to last over the course of 100 kilometers, which is why the shoe took its name from an insect with a 24-hour life cycle. Users were supposed to send the shoes back to Nike, where they would be recycled. That part didn’t quite work out as planned. Most people weren’t willing to part with the distinctive yellow and black, tree bark patterned Mayfly, planned obsolescence or not.