Nike Alphafly 4: 5 things (including the science) behind new marathon shoes

Here are five key facts about the Nike Alphafly 4 marathon shoe, along with the science behind its design:

1. Energy return: The Alphafly 4 stores and returns more energy with each stride compared to its predecessor, the Alphafly 3. Nike claims the Alphafly 4 offers 10 percent greater energy return.

2. Biomechanics research: Nike's Nike Sport Research Lab developed a mechanical model linking shoe properties to an athlete's running economy, quantifying how midsole materials store and return energy in joules to predict performance gains.

3. Lightweight design: The Alphafly 4 is 17 percent lighter and offers 8 percent more energy return than regular ZoomX foam, thanks to a new lightweight ZoomX LT foam that's layered above and below the Flyplate.

4. Improved comfort and stability: The Alphafly 4 features a more pronounced scoop geometry carbon-fibre Flyplate with a wider base for a wider overall platform and a more noticeable forefoot rocker. Dual Air Zoom pod units are made using a new process that makes them lighter and softer, and the shoe also uses a new outsole material called Light Shot for a quieter ride.

5. Athlete feedback and development: Nike collaborated with athletes and conducted biometric measurements to gather feedback and insights for design improvements. The Alphafly 4 was tested in development versions and has already been used in performances, including records in the half marathon and marathon.