I think I could still swim 20 laps a day, but it wouldn't all be in the same round, LOL. I would have to take a few breaks and I swim much, much slower than I did when I was young. I grew up in a beach resort town and weather permitting I swam every day in the Gulf of Mexico, which is a bit challenging depending on currents and waves. I learned how to swim when I was 3 years old, BTW, and most of my friends had pools too, so when it was rough in the Gulf I could go over to someone's house to swim. In my early 20s I lived in an apartment on the Intracoastal waterway (sound) and the apartment complex had a pool, too. The sound was always quite swimmable but I had to stay close to shore because of barges passing through. My dad had a boat so I was really active with water skiing, fishing, etc. and in my 20s I became SCUBA certified so I did that as well. And I also had show horses in my teenage years and I had to carry 50 pound sacks of horsefeed from the back of the pickup to the feedroom, haul buckets of water to their stalls, plus muck their stalls and then haul the wheelbarrows of manure out to the pile, LOL. That's hard work. I weighed about 105 as a teenager and about 115-120 in my 20s.
I sure do miss those days. It was the only way to battle summer was living close to the water. I lived in Tallahassee, Florida for a couple of years and the heat was a good 10 degrees hotter in the summer there, but it was just as humid.
Oh yeah, and beer has good food value but food has no beer value, LOL!