While hydrodynamics are very complicated a good rule of thumb is that form drag(pushing and pulling water by our body's shape) goes up as the square of velocity,where as wave drag goes up as the cube(these are not nearly exact but close enough at elite swimming velocities.)In all strokes you want your head in neutral position as much as possible as raising your head causes some other part to drop(usually hips.)Head up breaststroke is definitely slower,if you can avoid raising your head at all you will be faster(breath by raising your torso at the point where the insweep naturally causes it to rise.)
While hydrodynamics are very complicated a good rule of thumb is that form drag(pushing and pulling water by our body's shape) goes up as the square of velocity,where as wave drag goes up as the cube(these are not nearly exact but close enough at elite swimming velocities.)In all strokes you want your head in neutral position as much as possible as raising your head causes some other part to drop(usually hips.)Head up breaststroke is definitely slower,if you can avoid raising your head at all you will be faster(breath by raising your torso at the point where the insweep naturally causes it to rise.)
