For the first seven years of his life an accident of birth meant that McEvoy walked around on tiptoes, the consequence of shortened calf muscles and Achilles tendons. He still walks with a distinctive gait.
As McEvoy tells it, after filming his turns underwater, sports physiologists told him the inflexibility in his feet meant he was hitting the wall incorrectly. This was not good. He had to change.
“I decided to do some direction-of-force vector modelling and concluded that, in fact, it was an advantage. It was like my feet were spring-loaded. They agreed with my argument in the end, so I didn’t change.”
The tale is related not as an I-told-you-so moment. Rather, it comes out as an example of the enormous pleasure McEvoy derives from applying scientific rigour to extract truths.
The impression of a constantly whirring mind leads to the obvious question: does he use the silent space above that black line at the bottom of the pool to think complex thoughts, to solve complicated problems? Rarely, it turns out, although, “If I’ve come straight from a lecture and there’s something fresh on my mind, I might wrestle with it”.
And then a spark of memory. Picking up his phone, McEvoy starts swiping and tapping as he recalls the time he pondered optimal training loads during one session.
He turns the phone around. “I have been known to take over the (swim coach’s poolside) whiteboard occasionally,” he smiles, displaying a photo in which – clearly straight from the pool – he has filled a board with mathematical equations, amused teammates watching on.