Which procedure should be followed when stretching before a vigorous Workout

First perform a general warm-up then hold stretches for 15 to 30 seconds

First hold stretches for 15 to 30 seconds, then perform a general warm-up

First perfom a general wam-up then hold stretches for 60 seconds or longer

First hold stretches for 60 seconds or longer, then perform a general wamm-up​