Many people who come to stage combat have not studied martial arts and very often they have never been in a fight or in a sparring/fencing situation. So that you can play the force and structure of a hit — on both the giving and receiving ends, you’ll do yourself a favour if you get out and hit something. Um, let me rephrase that: find a boxing gym, a martial arts studio or a friends who know what they’re doing, and spend a bit of time with a heavy bag and focus mitts. This goes for swordplay, too! If you’re lucky enough to have a Western Martial Arts/Historical European Martial Arts salle nearby, give them a call and see if they have a pell or a live cutting opportunity in the near future. In either case, you must be sure to work with someone knowledgable: take all of their advice on proper structure or you risk injury.
Enjoy the visceral feeling of your body finding it’s perfect mechanical structure, and then practice that structure without a target. Finally, file the experience away so that you can approximate it again in the context of a scene. Not all acting requires that you actually experience the moment beforehand, but in the case of this physical art form, it sure helps!