[_qbxi]

My university required a swim test to graduate, and also required 10 minutes of treading water in order to access sailboats. Many of my classmates talked about this being difficult, but both were trivial for me.

Fat is buoyant.

[galangalalgol]

Yeah you can have lots of spare energy and still be quite strong with great cardiovascular health. It is hard on the joints though.

[JumpCrisscross]

Some body fat is absolutely helpful in protecting from drowning [1]. You see a similar curve when mapping life expectancy and mortality risk against BMI—the optimum is a bit thicker than our guidance suggests. (Saying this as someone who has to fight to keep weight on.)

[1] https://pubmed.ncbi.nlm.nih.gov/28915131/