Start on all fours, with your hands stacked under your shoulders and your knees stacked under your hips. Engage your core and maintain a flat back. Place your left hand on the back of your head, so that your elbow points out to the left side. Rest the hand lightly�don't put pressure on your head or neck. This is starting position. Slowly rotate your head and shoulder toward your right hand on the floor. Then, reverse the motion and rotate to the left and up so your elbow points toward the ceiling. Hold for a moment and then return to the starting position. Continue this movement for 20 seconds.

Start on your hands and knees in tabletop position with your wrists stacked under your shoulders and your knees stacked under your hips. Extend your left arm forward and right leg back, maintaining a flat back and keeping your hips in line with the floor. Think about driving your foot toward the wall behind you. Squeeze your abs and draw your left elbow and right knee in to meet near the center of your body. Reverse the movement and extend your arm and leg back out. Keep your right foot flexed throughout the exercise. Continue this movement for 20 seconds.

Start on all fours, with your hands stacked under your shoulders and your knees stacked under your hips. Engage your core and maintain a flat back. Engage your core, and while keeping your back flat and your butt down (like you're in a plank), lift your knees off the floor about 1 to 3 inches. Gaze at the floor a few inches in front of your hands to keep your neck in a comfortable position. While keeping your core super engaged, extend your left arm directly out in front of you. Hold for a second, and then move the arm out to the left side so that it�s perpendicular to your body. Then, bring it back so it�s extended in front of you again. Continue this movement for 20 seconds. If you're having a tough time keeping your hips stable, take out the arm movement and just hold for 20 seconds.

Lie faceup with your arms by your sides and legs straight. Engage your core and roll your torso up while driving your right arm forward and your left knee to your chest. Reverse the movement to roll back down to the floor in a controlled motion, letting your leg and shoulders briefly touch the floor. Immediately move into the next rep to maintain engagement in your core. Continue for 20 seconds.

Lie face up with your legs in tabletop position (knees bent 90 degrees and stacked over your hips). Place your hands behind your head, elbows bent and pointing out to the sides. Use your abs to curl your shoulders off the floor. This is the starting position. Twist to bring your right elbow to your left knee, while simultaneously straightening your right leg. Hold this position for a second (right elbow and left knee touching or almost touching), and then slowly pulse the knee and elbow apart just a couple of inches, and then back together. Continue this in-and-out pulsing motion for 20 seconds.

From the bicycle crunch position, extend your left leg straight into the air so the bottom of your left foot is facing the ceiling. Extend your left arm out to the side and reach your right arm up toward your left foot, crunching your torso up a few inches as you do. Slowly pulse your upper body and right arm up toward your left foot a couple of inches, and then back a couple of inches. Continue this up-and-down pulsing motion for 20 seconds.

Lie face up in a starfish position with your legs extended and right arm extended overhead on the floor. Extend your left arm out to the left side of your body. Contract your abs to press your lower back into the ground. This is the starting position. Engage your thighs and glutes and simultaneously lift your left leg, right arm, and upper back off the ground, reaching across your body to touch your right hand to meet your left ankle. Use your left arm to help maintain balance as you rise. Keep your core engaged as you lower to return to the starting position. Continue this movement for 20 seconds.

Start in a forearm side plank by propping your body up on your left forearm, with your elbow stacked underneath your shoulder and your hand in front of your body. Extend your legs and stack your right foot on top of your left, and then squeeze your abs and glutes to lift your hips off the floor. Extend your right arm overhead (as pictured) or place it on your left hip. Your shoulders, hips, and feet should all be in one line. Slowly dip your hips toward the floor, keeping your core tight and your back flat. Then, lift your hips back up. This is 1 rep. Do 10 pulses and then 10 seconds of full hip dips (all the way to the floor) on one side.

Rest your forearms on the floor, with your elbows directly underneath your shoulders and hands facing forward so that your arms are parallel. Extend your legs out behind you and rest your toes on the floor. Your body should form one straight line from your shoulders to your heels. Squeeze your entire core, your glutes, and your quads, and tuck your butt under a little to keep your lower back straight. Make sure you are not dropping your hips or hiking your butt up high toward the ceiling. Position your head so that your neck is in a neutral position and your gaze is on your hands. Hold this position.

Start on all fours. Engage your core and while keeping your back flat and your butt down (like you're in a plank), lift your knees off the floor about 1-3 inches. Gaze at the floor a few inches in front of your hands to keep your neck in a comfortable position. Tap your right hand to your left shoulder, and then your left hand to your right shoulder, while using your core strength to keep your hips as still as you can. Continue alternating sides.

Lie face up with the soles of your feet together, knees bent out to sides. Reach your arms overhead. This is starting position. Using your core, roll your body up until you are sitting upright. Reach forward to touch your toes. That's 1 rep. Slowly lower back down to starting position and continue immediately into the next rep.

Lie face up with your legs extended and arms by your sides. Contract your abs to press your low back into ground. This is starting position. Squeeze your thighs together, squeeze your glutes, and simultaneously lift your left leg and upper back off the ground, reaching your right hand forward to meet your left foot. Your torso and your left leg should form a V. Keep your core engaged as you slowly lower to return to starting position. Repeat with the opposite leg and arm. Continue alternating sides.

Put your toes on a set of gliders or towels and then get into a forearm plank with your forearms on the floor, elbows directly underneath your shoulders, hands facing forward so that your arms are parallel, and legs extended behind you. Tuck your tailbone and engage your core, butt, and quads. This is starting position. Slowly push with your forearms and elbows to slide the gliders or towels back toward the wall behind you. Move as far as you can without losing core engagement. Don't let your hips sag. Slowly pull with your arms and elbows to return to the starting position.

Lie face up with your legs extended and arms straight over your head, keeping them close to your ears. Contract your abs to press your low back into ground. Point your toes, squeeze your thighs together, squeeze your glutes, and lift your legs off the ground. Lift your shoulders off the ground and keep your head in a neutral position so that you're not straining your neck. Your legs and mid-back should both be off the ground, and you should be in the shape of a banana with just your low back and hips on the ground. This is starting position, a hollow hold. Stay in the hollow hold position for as long as you can, up to 10 seconds. Then, lift your arms and legs to meet so that your body forms a "V" hold for a breath, and slowly lower back down to hollow hold position.

Lie face up with your legs extended and arms straight over your head, keeping them close to your ears. Contract your abs to press your low back into ground. Point your toes, squeeze your thighs together, squeeze your glutes, and lift your legs off the ground. Lift your shoulders off the ground and keep your head in a neutral position so that you're not straining your neck. Your legs and mid-back should both be off the ground, and you should be in the shape of a banana with just your low back and hips on the ground. This is starting position. Slowly rock forward and back, keeping everything tight, to the point that your feet and hands nearly touch the floor. If this is too difficult, get into the starting position and simply hold.

Sit on your tailbone with your knees bent and feet flat on the floor. Hold onto each leg just above the knee. Round your spine, tuck your tailbone, and begin to lower your torso back, as if you were lowering back after a sit-up. About halfway (like in the photo above), stop and hold. Keep your entire core and your quads engaged. For an extra challenge, let go of your legs and just hold your arms out in front of you.

Start on all fours with a glider or towel under each hand. Squeeze your core and tuck your tailbone so that your back is flat, like you're doing a plank from your knees. This is starting position. Slowly push your hands in front of you, keeping your arms straight. Glide as far as you can while still maintaining your torso in a plank position. Press into the floor and pull your arms back to return to starting position.

Start in a side plank with your right hand on the floor, directly underneath your right shoulder, and your feet staggered so the left is right in front of the right (as shown). You can also stack your left foot on top of your right. Engage your core and your butt. Let your left arm relax by your left side. Dip your hips down toward the ground and then lift them back up. This is 1 rep. Do all your reps on one side, and then repeat on the other side.

Sit up tall with your knees bent and feet flat on the floor. Wrap your arms around your legs and hold onto the outside of your ankles. Curl your head and chest forward in toward your knees. Scoop your core muscles in deeply, then roll your body back until your shoulders touch the ground. Don't roll so far that your neck or head touches the ground. Rock back up to a seated position.

Lie face up with your legs raised in a tabletop position (knees bent 90 degrees and stacked over your hips). Contract your abs to press your low back into ground. Crunch up just a few inches and place your hands on the front of your quads. Drive your quads into your hands while simultaneously pressing them away. There should be no visible movement in your body, but you should feel the battle and intense tension in your core.

Lie face up with your legs extended and hands at your sides or tucked underneath your hips for extra support. Slowly raise your legs, keeping them together and as straight as possible, until the soles of your shoes are facing the ceiling. Then, slowly lower your legs back down. Don�t let your feet touch the floor; instead, keep them hovering a few inches off. That's 1 rep. As you do this move, make sure to keep your lower back flat on the floor. If you're having a tough time doing that, don't lower your legs as far.

Start in a forearm plank with your forearms on the floor, elbows directly underneath your shoulders, hands facing forward so that your arms are parallel, and legs extended behind you. Tuck your tailbone and engage your core, butt, and quads. Rotate your hips to the left side and tap the floor. Repeat on the right side. Continue alternating sides.

Lie face up with your legs extended and arms extended overhead on the floor, keeping them close to your ears. Contract your abs to press your low back into ground. This is starting position. Point your toes, squeeze your thighs together, squeeze your glutes, and simultaneously lift your legs and upper back off the ground, reaching your hands forward to meet your feet so that your body forms a V. Keep your core engaged as you slowly lower to return to starting position.

Lie face up with your arms extended toward the ceiling and your legs in a tabletop position (knees bent 90 degrees and stacked over your hips). This is starting position. Slowly extend your right leg out straight, while simultaneously dropping your left arm overhead. Keep both a few inches from the ground. Squeeze your butt and keep your core engaged the entire time, lower back pressed into the floor. Bring your arm and leg back to the starting position. Repeat on the other side, extending your left leg and your right arm.

Start in a high plank position with your palms flat on the floor, hands shoulder-width apart, shoulders stacked directly above your wrists, legs extended behind you, and your core and glutes engaged. Tap your right hand to your left shoulder while engaging your core and glutes to keep your hips as still as possible. Try not to rock at the hips. Do the same thing with your left hand to right shoulder. Continue alternating sides.

Start on your knees, and then step one leg a few feet in front of the other, foot flat on the floor and knee bent at 90 degrees. Hold a light-to-medium dumbbell by the knee that's on the floor. Grasp onto both ends of the weight. This is starting position. Bring the weight diagonally up toward the ceiling on the opposite side of your body, twisting your abs as you do. Keep your hips facing forward�only your core muscles should be rotating. Bring the weight back down to starting position. Do all your reps on one side, and then repeat on the other side.

Sit up straight with your legs bent, feet flat on the floor. Keeping your legs together, slowly lift them off the floor until they form a 45-degree angle to your torso. Engage your entire core, keep your back flat, and balance on your tailbone. You can keep your knees bent (as pictured) or straighten them out for more of a challenge. Reach your arms straight out in front of you, parallel to the floor. If you feel that you need some extra support, place your hands on the floor, underneath your hips. This is High Boat. Hold here for three deep breaths. Then, lower your legs, straightening them out, while also lowering your upper body. Both your shoulder blades and legs should hover a few inches off the floor. If that is too challenging, keep them slightly higher off the floor and work toward bringing them lower and lower. This is Low Boat. Hold for one breath, and then lift your legs and torso back to High Boat.

Sit up straight with your legs bent, feet flat on the floor. Keeping your legs together, slowly lift them off the floor until they form a 45-degree angle to your torso. Engage your entire core, keep your back flat, and balance on your tailbone. You can keep your knees bent (as pictured) or straighten them out for more of a challenge. Reach your arms straight out in front of you, parallel to the floor. If you feel that you need some extra support, place your hands on the floor, underneath your hips. This is High Boat. From here, clasp your hands in front of you and twist at the waist toward one side, swinging your arms to the same side as if you had an oar in your hands and you were rowing. Immediately twist to the opposite side and repeat the same arm movement. Continue alternating sides.

Get into proper position by locking your arms in a fixed overhead position. You can do this on a bench, with your hand next to your head and gripping the sides of the bench, or you can grip a stable object overhead. Some people use kettlebells or a barbell, but using something fixed and stable is a bit more practical, and quite a bit safer. Contract your torso and drive your legs up as if you are performing a reverse crunch, but keep your body rigid from your shoulders to toes, and avoid bending the hips. Point your toes to help maintain proper body alignment. Once lifted, slowly lower your legs in a controlled motion without letting any part of your body touch the bench other than the upper back and shoulder. If you cave in, drop your hips, or arch your back, you don't have the strength yet and you should not continue the exercise. Lower your body until it is hovering just over the bench. Repeat as possible. Once you break form, you are done.

Get into a plank position, making sure to distribute your weight evenly between your hands and your toes. Check your form�your hands should be about shoulder-width apart, back flat, abs engaged, and head in alignment. Pull your right knee into your chest as far as you can. Switch legs, pulling one knee out and bringing the other knee in. Keep your hips down and run your knees in and out as far and as fast as you can. Alternate inhaling and exhaling with each leg change.

Begin lying on your back with your legs together and your arms reaching straight down to your toes. Press your arms into the floor, raise your legs off the floor and point your toes up to the ceiling, then to the wall behind you. You will need to peel your tailbone and pelvis off the floor and aim to have your legs parallel to the floor.

Lie on the mat with your arms extended straight over your chest so they form a perpendicular angle with your torso. Bend your hips and knees 90-degrees, lifting your feet from the ground. Your torso and thighs should form a right angle, as should your thighs and shins. This is the starting position Engage your core, maintaining contact between your lower back and the mat. You want to make sure your spine maintains this steady and neutral position throughout the exercise. Keep your right arm and left leg exactly where they are, then slowly reach your left arm backward, over your head and toward the floor as you simultaneously extend your right knee and hip, reaching your right heel toward the floor. Move slowly and steadily, breathing in as you perform the extensions, avoiding any twisting or movement of your hips and abs. Stop the movement just before your arm and leg touch the ground. Reverse the movement and return your left arm and right leg to their starting positions. Move slowly and steadily, exhaling as you go. Perform the same movements to the opposite sides, this time keeping your left arm and right leg steady as you extend your right arm and left leg. Do the same number of repetitions on each side. When you complete a full set, simply return your feet to the ground and sit up.

Lie on your back and extend your arms behind your head. Keep your feet together and toes pointed. Keep your legs straight and lift them up as you simultaneously raise your upper body off the floor. Keep your core tight as you reach for your toes with your hands. Slowly lower yourself back down to the starting position.

Stand with your feet at your preferred width. Bending at your hips, lean forward and place the wheel in front of you. Keep your arms straight. Roll forward on the wheel until your arms are above your head and your body is parallel to the floor. Hold for a moment once you reach full extension. Roll the wheel back toward you, bending at the hips so you return to your starting standing position. Aim for 10 reps � if you can.

Kneel on a mat or cushion with the ab wheel directly in front of you. Grip the handles and support yourself with arms fully extended. Keep your back and arms straight as you move the wheel forward and away from you. Extend your body as far into a plank position as you can go. Try to retain the ability to roll back into a neutral position. Hold for a moment before steadily returning to the starting position. Aim for 2�3 sets of 10�15 reps.

Sit on the floor and bring your legs out straight. Lean back slightly so your torso and legs form a V-like shape, bracing your abdominal wall to engage your core. Balancing here and keeping your legs stationary, twist your torso from side to side. Remember to move slowly and breathe, says Donohoe. Don't disengage your core when fatigue sets in.

Bend your legs at the knee and brace your abs to slowly raise your legs so the knees are directly over your hips and your lower legs are parallel to the floor (bent 90 degrees). This is the starting position. Brace the abdominal muscles and hold a neutral spine position with a slight natural curve in the lower back (lumbar) region yet with the back firmly against the floor. Exhale as you contract the abs to curl your hips and knees toward your chest, with only your hips coming off the mat as you curl. Your knees should remain at the same angle throughout this upward phase. Your head should be kept straight and the neck and shoulders should remain relaxed and on the mat. Hold when you cannot curl without your back coming off the mat. Inhale and slowly return to the starting position with your hips back on the mat and your knees over your hips, still bent 90 degrees.

Start on your right side with your right forearm directly underneath your shoulder. Stack your feet and lift up your hips until your body forms a straight line. Extend your left arm straight out. Engage your abdominal muscles, drawing your navel toward your spine.Pulse your hips toward the sky for at least 30 seconds, then repeat on the other side.

Get down on the floor so that you are resting on your elbows with feet about hip-width apart. Scoot the elbow forward so they are at least 6 inches out in front of your shoulders. Bring one knee off the ground at a time so that your legs are fully extended. Engage your abs, glutes, and quadriceps while you take big breaths through your belly.

Lie on your back with legs hinged at the knees and arms pointing towards the ceiling. Engage your core muscles, lower back needs to be flat on the floor. Lift both your pelvis and your upper body into a crunch. Extend your arms and legs for increase in difficulty.

Bend your legs at the knee and brace your abs to slowly raise your legs so the knees are directly over your hips and your lower legs are parallel to the floor (bent 90 degrees). This is the starting position. Brace the abdominal muscles and hold a neutral spine position with a slight natural curve in the lower back (lumbar) region yet with the back firmly against the floor. Exhale as you contract the abs to curl your hips and knees toward your chest, with only your hips coming off the mat as you curl. Your knees should remain at the same angle throughout this upward phase. Your head should be kept straight and the neck and shoulders should remain relaxed and on the mat. Hold when you cannot curl without your back coming off the mat. Inhale and slowly return to the starting position with your hips back on the mat and your knees over your hips, still bent 90 degrees.

Lie on your back with your arms stretched. Engage your core muscles while tucking your legs in, bending them at the knees and moving your arms so you can touch your heels.

Lie on your back, legs straight and together. Keep your legs straight and lift them all the way up to the ceiling until your butt comes off the floor. Slowly lower your legs back down till they�re just above the floor. Hold for a moment. Raise your legs back up. Repeat.

Lie on your back and extend your arms behind your head. Keep your feet together and toes pointed. Keep your legs straight and lift them up as you simultaneously raise your upper body off the floor. Keep your core tight as you reach for your toes with your hands. Slowly lower yourself back down to the starting position.

Lie face up with the soles of your feet together, knees bent out to sides. Reach your arms overhead. This is starting position. Using your core, roll your body up until you are sitting upright. Reach forward to touch your toes. That's 1 rep. Slowly lower back down to starting position and continue immediately into the next rep.

Place either your right or left elbow on the floor, lift your hips, and extend both legs. Balance on the outside edge of your bottom foot and lift top leg up just a bit higher than your hip. Slowly lower top leg back down. Repeat on the other side.
Help out your balance by keeping your free hand on your hip or extended in the air. Keep your feet flexed if you can.

Extend your arms in front of your body instead of placing the hands underneath your shoulders as you would do for a normal push-up. Lift yourself with your core.

We perform our pushup, and as we come up, we get this bottom-up rotation of the knee heading towards the opposite elbow. In order to get that core activated even more, we have to drive and slide that knee up as high as we can.

Firstly, place your feet up against the wall with a little bit of pressure - the feet should just be touching, but actually pushing in. Then take a yoga block and squeeze it between your knees. When squeezing the block, use intense effort, really trying to crush it. This does couple of things - activating the deep core muscles and firing up your adductors. This makes it difficuly for the hips to get involved, which will make your abs actually have to do the work. Now time to roll up the spine vertebrae by vertebrae - upper back, mid and low back come up one by one. Very important is to go back slowly - drop the lower back first, then mid, then upper back. This whole movement should be done in slow and controlled manner. This is not an explosive exercise. Focus on mind-muscle connection.

Assume a bear crawl position: Get down on all fours with your arms straight, hands below your shoulders, and your knees bent 90 degrees below your hips. (Only your hands and toes should touch the ground.) Keeping your left hand and right foot on the floor, rotate your torso to the right as you bring your left knee and right elbow together. Reverse the move to return to the starting position, and repeat on your other side. Continue alternating sides, performing equal reps on both.

Keep your back pressed hard into the floor.

20 seconds each side.

Go slow and drive your knee into your tummy.

Use your core to stabilize yourself as you lower your feet to the floor. Use your abs to bring your legs back up.

Go slow, this burns.