When considered from a scientific point of view, martial arts are an effective way of applying the laws of physics and bio dynamics to both your body and to the body of your opponent.
Most people, when asked to perform a movement that involve strength (e.g. lifting a heavy object, shifting a heavy piece of furniture around or push start a car) will erroneously use certain parts of the body that do not optimise the alignment of muscles, tendons, joints and more important will not join and align correctly the vectors of the various forces involved in the movement. A properly trained martial artist will have both a conscious and unconscious co-ordination in most movements and she will look stronger than other people of equivalent build who are untrained.
Excluding movies and TV special effects – when you see anything that seems very difficult or impossible to perform from your point of view just think that there is no magic, no trick involved: just the correct use of limbs and weight alignment.
Concepts like power, gravity, friction, momentum, kinetic energy and impulse have direct use and application in usual training drills of all martial arts. For this reason they could be easily called martial sciences: the scientific studies of how to fight.
So the question for you is: how aware are you of the correct way of aligning forces when delivering a punch or a kick? How much is your instructor or coach explaining why and how power can be obtained and improved with proper execution of a techniques rather than shire force?