The 8-Minute Fat Blast Moves The first high intensity move is the jumping jack. Same old thing, bring those arms up and lock. Good! Bend your knees, stretch your legs and fast. Now this is so interesting, you can take it to a half jack. Step it out. And, as you get stronger and more fit, work your way back up to the regular jumping jack. You don't have to jump high. For more intensity, speed it up. There you go. Remember, work it out with your own intensity.