I sure can tell the difference between classmates who take the hard qigong class (iron shirt training) and those who don't. Hands ,feet, legs are just heavier...and they take harder hits than anyone else.
With any class, some are better at reading intent, some have faster reaction time, some are more accurate in their strikes and techniques....all time and practice.
I like how many mantis techniques involve avoiding the hit while doing damage or incapacitating the weapon.
"The true meaning of a given movement in a form is not its application, but rather the unlimited potential of the mind to provide muscular and skeletal support for that movement." Gregory Fong