Track and field athlete Ashton Eaton, a gold medalist in the decathlon at the 2012 and 2016 Olympics, says that tennis is the most athletic sport following his own.
The decathlon, which involves competing in ten track-and-field events across two days, is regarded as the standard for measuring all-around athleticism.
"I personally believe tennis is the next most athletic sport," Eaton told *Business Insider*. "Just because of certain things required. Those matches are three or four hours long. There’s the technical aspect, the agility, the mind-body awareness. Not to mention the game itself is a little bit like a chess match."
When asked to compare tennis players with NFL or NBA participants, or name the top athlete across sports, Eaton would not offer specific names.
"I don't have one specific person that I think is the most athletic person," he said, suggesting that a complex set of measurements would be required.
However, he added that it was important to also look at the mental component and not just the physical component, saying, "You can speculate all day, by what you perceive people to do, but I think there’s two aspects to athleticism...People like to focus on just the body part."
The interview was given during a sponsorship appearance.