I was a rescue diver for the fire department. Before we could get in the water we where required to pass a medical test. It consisted of: Background, stress test, hearing test, lung test(blow into a spirometer), a couple of things involving rubber gloves and KY, some x rays.

How about some expert opinions on extent and frequency for medical testing for Rebreather diving.

Also we swam hard at least twice a week. The test for surface rescue (lifeguard) requires 500 meters or 550 yards in 10 miniutes.

best wishes and stay safe.