I like the workouts here, but there's a serious mistake in "Dumbbell Butterfly Swim Stroke." The author says, "The butterfly swimming stroke, as any swimmer knows, works your shoulders through a full circular motion. Here you replace the resistance of the water with dumbbells."

That's just wrong. In the butterfly, the swimmer is PUSHING his hands down through the water, but in the dumbbell exercise, you're trying to SLOW the downward motion of the dumbbells (i.e, you're PULLING up, though not hard enough to counteract gravity), which uses a different set of muscles from the swimming stroke.

The article ought to be fixed.