Anyone who has split logs badly has learned this the hard way. Swing harder and the axe bounces off. Let the weight of the head drop into a crack the wood already has, and the log opens with almost nothing asked of the person holding the handle.
Most forcing is a sign that something upstream is wrong — the wrong tool, the wrong moment, the wrong person to be asking. Effort applied to the actual obstacle rarely feels like straining. It feels like work, which is a different sensation entirely.
Natural power is quieter than it sounds. Mostly it is knowing where the wood was already going to come apart.