A cool pool is better for laps.

78 to 82 degrees Fahrenheit. That’s the range you want.

Warmer than 82° and you’ll overheat within ten laps. Your body can’t dump heat fast enough, so you feel sluggish and breathless. Colder than 78° and your muscles stay tight, and your stroke feels stiff.

Competition pools sit at 79-81° for a reason—it’s the Goldilocks zone where you can push hard without cramping or overheating. If your local pool runs at 84° (many “recreation” pools do), you’re basically swimming in soup.

If you’re just splashing around, go warmer. But for actual lap swimming, cooler is better.

Future you will thank past you for not swimming in a bathtub.