Anyone travelling to Frankfurt, stay at the Hilton. Guests have access to the athletic club next door which has a 25 m pool far superior to my local Lifetime fitness pools. Extra wide lanes and very clean.
Highly recommended.
Try the Rebstockbad at the park. Great Lap Pool! Huge wave pool that is great to swim laps in! Even a water slide to wind down on when you finish your workout. Couple of Euro for admission!