I worked for 2 years in a co-working space full of founders next to ETH Zurich. The most consistent worker? The cleaning lady. Every morning at 6 am, she did not miss a single day.
I grew up in a small village in Germany. 500 people, 5000 cows. Only farmers and a cheese factory. In the factory, we worked on Christmas, Easter, and New Year's Eve every morning at 5 am. Farmers don't take days off because cows don't take days off.
Maybe it's not the most healthy way of life. I don't think it physically requires us to take time.