[JoshTriplett]

I had similar exercises when swimming: 4x25m with 3 breaths each 25m, 4x25m with 2 breaths each 25m, 4x25m with 1 breath each 25m, and 4x25m where you only breath when you hit the wall and turn. There are similar variants for 50m.

That made a huge difference expanding my lung capacity, and I still have most of that expanded lung capacity today.