I'm vasa curious but have never tried one.

If people want to really toughen up the strength endurance then - I am blanking on the names but I am pretty sure it is Laidlaw. His dad coaches him. He says he just swims but has these weighted rocks that he holds, that would make your arms really strong. He says 5k sessions with his dad are like 8k sessions with other coaches. That would make your shoulders really tough and a weapon in a wetsuit.

For those who have used a vasa, how much pressure does it put on your core and the ab muscles up above your hips? I think those muscles are quite important for swimming too, or the coordination of activating them in some way.

Also - vasa would be awesome if you were training for board paddle racing in the surf life saving / life guard events.