Once again, SI is revealing its Fittest 50 list, designed to recognize the athletes at the absolute peak of physical fitness. The list takes into account attributes like speed, power and flexibility and cross-sport questions like: How effective would LeBron James be as a football player? Where would Serena Williams finish in a marathon? Welcome to the SI Fittest 50.
Fittest 50 Criteria: Why Giannis and Simone Biles Came Out on Top
What measures and benchmarks should we use when comparing athletes of all shapes and sizes, from disparate sports? Here's an inside look at how SI choose its 2020 Fittest 50 and why Simone Biles and Giannis Antetokounmpo are this year's top athletes.