[Christ]

The general consensus, from what I gather, is that most of the work generated to push the spring down is just returned when the spring pushes back against the rocker, helping to turn the cam around.

I don't necessarily subscribe to this belief, for a few reasons that I hold personally, but that's not for this thread.

Regardless, you can turn the cam by hand, it doesn't even take more than a few lb/ft of force to turn the cam against the springs, so there's not enough loss there to really worry about.