Why do planks—and even harder plank variations? Each move shifts your center of gravity and forces your abdominals, arms, back, and glutes to stabilize your body. Not to mention, the plank is an effective, full-body move that doesn't require lots of space, fancy equipment, or a gym membership.
Fitness trainer and registered yoga teacher Stacey Lei Krauss, the founder and creator of the Cardio Yoga program, designed this 10-minute, five-move plank sequence, which includes several variations on the standard plank position.
To get started, simply clear a space on the floor. Complete the entire cycle three times per week, taking 30 seconds between each move to roll your wrists and shoulders, and you'll achieve stronger core muscles, improved balance, and a true sense of accomplishment—without even touching a set of weights or (if you're like Krauss, who prefers to go barefoot) lacing up your sneakers.
(A) Begin on all fours, with hands directly under shoulders, knees and feet hip-distance apart and fingers spread out. If you're a beginner, rest on your forearms instead. (This also applies to all subsequent exercises.)
(B) Tuck toes underneath feet so that all 10 toes lie flat. Extend legs and push up hips so that your body is in a straight line from shoulders to heels. Draw in your abs, squeeze your glutes, and keep your head in a neutral position that's in line with your spine. Hold for 30 seconds. (Don't forget to breathe!)
(B) Lift your right leg three inches off the floor, pointing your toes and keeping your leg straight. With your torso completely still, gently and quickly pulse your leg up and down five times, firing up your glutes, hamstrings, and quad muscles. Return to the starting position. This is one rep. Repeat 9 times, then switch sides and do 10 more.
(B) Lift your right leg three inches off the floor, pointing your toes, and draw your right knee toward your chest and diagonally across your body until your knee taps your left elbow (or your left armpit if you're resting on your forearms). Return to the starting position. Repeat 9 times, then switch sides and do 10 more.
(B) With your abs engaged, rotate your right shoulder and hip up toward the ceiling in one fluid movement, twisting your feet so that the inside of your right foot and the outside of your left foot rest on the floor. Extend your arm so that it's pointing toward the ceiling. Return to the starting position. Repeat four times, then switch sides and do five more.
(A) Begin in a modified version of the standard plank position, placing your feet several inches wider than hip-distance apart and your hands underneath your chest. Turn your hands slightly toward each other so that your thumbs and index fingers touch to form an upside-down heart.
(B) Use your toes to push your body and rock forward so that the center of your chest aligns over the heart formed by your hands. Keep your chest, back, and triceps engaged and hold for 30 seconds. It's a very subtle movement that punks serious punch.