Recently, I read an interesting story about A. Weil and J.P. Serre. The general gist of the story is as follows:
During the Autumn of 1955, an international symposium on algebraic number theory was held at Nikko [a small city around 150 km north of Tokyo]. The Japanese mathematicians invited Weil and Serre on a trip to Lake Chuzenji. Upon arriving, Weil and Serre stripped down, and started swimming in the cold lake. The Japanese mathematicians followed suit, but they quickly gave up because of the cold. After a while, the two mathematicians came back out and started running. The Japanese mathematicians ran after the duo, but once again, they gave up. Eventually, Weil came back, smiled at the Japanese mathematicians, and said, "Math is all about physical stamina."
I think the last Weil quote sums up the main message of the story.
My Question. Based on people's experience, is this a true statement? If possible, I would like to hear what physical activities people pursue, and in what ways that has helped in doing mathematics.
I hope this is not too off-topic. I've never heard something like this from mathematicians I know personally, so I was curious to hear what the community thinks.
Edit. As per helpful comments, I would like to restrict the question to research mathematics (rather than mathematics in general).