Surprisingly there are skilled but unfit cave divers. You are neutrally buoyant most of the time with little need for major physical exertion. I was a technical

Surprisingly there are skilled but unfit cave divers. You are neutrally buoyant most of the time with little need for major physical exertion. I was a technical driver for over 6 years. The more efficient you become the less energy and air you use. I like to parachute and motorcycle too. I am a certified rope technician (SPRAT) and that takes the most physical exertion of the bunch for me, but that gets better with skill too. Gravity, the plane and the moto do most of the work for the others. That's why I go to a boxing gym for fitness among other activities.