if you have a busy schedule and need to get things done fast, follow my full core workout for people in a hurry series. make sure you watch the videos about the instruction of these exercises below as well.
some of these exercises are shown with different variations. make sure you watch the videos first and then do the exercises and not while you are doing them so you have a better focus on what you are doing.
warm-up and dynamic stretching:
cool-down and static stretching: https://youtu.be/w6lEw7ZqfiI
main core videos:
kickback: https://youtu.be/9P0G3OJIg1Q
superman and Birddog: https://youtu.be/AidnCNdxGV4
mountain climbers: https://youtu.be/_LVZ7Sgom4w
make sure you do the warm-up and cool-down as well.