Yes, insofar as it enhances one's physical capabilities. Eg. super speed, strength, resilience, regeneration, etc. However, it can also be used to affect others to either help or hinder them. For example, using your ki to heal other people's wounds or help them regain stamina at the cost of your own. It can even be used for mind control like incapacitating weaker enemies without even fighting (basically Conqueror's haki from One Piece). In the setting of the roleplay, ki can be applied in many different ways asides from simply augmenting physical strength. Think of it as life or soul magic whereas mages have power over the elements.