This workout was inspired by portions of a lower body + abs workout I taught on Monday night, and the class loved it, so I thought I'd share it with you here. It incorporates both dynamic and isometric exercises for the abs, which are great for isolation and really tiring out muscle groups. To give you a bit of a background, dynamic exercises involve lengthening and shortening the desired muscle(s) with some type of resistance (in this case, gravity). The muscle shortening part of an exercise is called the concentric phase, while the lengthening part is called the eccentric phase. Isometric exercises involve holding the particular muscle(s) in a contracted state without shortening or lengthening it (i.e. staying still).

So today we'll be focusing on our abs with some crunch variations, planks (+ variations), and a few other moves that all require no equipment. This workout will take you about 12 minutes to complete one time through, so about 24 minutes total for the recommended 2x. Ready to get started?!

No Equipment Dynamic Abs Workout with Isometric Holds

For each exercise, start with the dynamic (concentric + eccentric) part of the move for 30 seconds. Then you'll hold the position for 30 seconds (isometric). Let's work those abs!

Round 1

1. Birddog Plank (dynamic) - start in a regular plank position, hands in line with your shoulders, abs engaged, gaze forward. From here, simultaneously lift your opposite arm and opposite leg straight up to form a line. Hold for a second, then place them back down and do the same on the other side. Keep alternating for 30 seconds.
Low Plank Hold (isometric) - come down into a low plank on your forearms, palms up, and hold the position for 30 seconds, keeping your spine neutral and abs engaged.

2. Side Plank Pulses, right (dynamic) - start in a low side plank on your right side, either feet stacked (harder), or right leg tucked underneath you (easier), elbow under your shoulder. Lift your hips up so your body forms a straight line head to toe. From here, pulse your hips up and down (small movements) for 30 seconds.
Side Plank Hold (isometric) - return to the starting position with your body in a straight line and hold it for 30 seconds.

3. Russian Twists, arms folded (dynamic) - start seated with your feet either flat on the floor or legs raised to a 90˚ angle, leaning back slightly to engage the abs, arms crossed "I Dream of Genie" style in front of you. From here, bring your arms down to one side and touch your elbow to the floor. Raise it back up and do the same on the other side, engaging your obliques as you twist. Keep twisting for 30 seconds.
V-hold (isometric) - return to the starting position and extend your legs up so your body forms a V. Hold that position for 30 seconds.

4. Side Plank Pulses, left (dynamic) + hold (isometric)

Round 2

1. Alternating Toe Tap Crunches (dynamic) - start lying on your back, legs extended out straight, feet flexed, arms extended flat on the floor above you. From here, bring one knee up to meet your chest in the middle while reaching to touch those toes. Lower back down and immediately do the same thing on the other side. Keep alternating for 30 seconds.
Crunch Hold (isometric) - bring both knees into your chest and touch your toes like you did in the toe taps. Hold that position for 30 seconds.

2. In & Outs (dynamic) - sit down on the floor, legs extended with hands by your sides, forearms on the ground. Keeping your forearms planted, bring your knees in toward your chest, engaging your abs. Extend back out to start, hovering your feet over the floor but NOT touching. Keep alternating in & outs for 30 seconds.
Extension Hold (isometric) - on your last "out" part of the in & out, hold yourself in that position for 30 seconds. Legs and feet hovering just above the floor, abs firing to keep them raised.

3. Alternating Table Toe Taps (dynamic) - start in a table top position (feet and hands flat on the ground, fingers facing your heels, pelvis raised toward the ceiling). From here, alternating bringing the opposite arm and opposite leg up to meet in the middle and tap your toes. Your hips will dip a little here and that's okay. Lower them back down, and do the same on the other side. Keep alternating for 30 seconds.
Table Top Hold (isometric) - keep your feet and hands flat on the ground and raise your pelvis up toward the ceiling, forming a "table top" with your torso. Try to keep your hips elevated and your spine as neutral as possible. Hold for 30 seconds.

4. Knee to Elbow Push Ups (dynamic) - start in a push up position, and as you lower yourself down, bring one knee out to the side to reach your elbow. Raise back up to start and repeat on the other side. Keep alternating for 30 seconds.
Superman Plank (isometric) - this is tough, so try your best! From a regular plank position, walk your hands and feet out a little further so your body is lower to the ground. You'll have to really press with your hands and engage your abs to stay elevated. Hold for 30 seconds. Trainer Tip: if this one is too much for you, hold a regular plank.

Round 3

1. Pike to Alternating Knee Tuck (dynamic) - start in a pike position (like a down dog). From here, lower yourself down to a regular plank, bringing one knee in toward your chest and squeezing your abs as you do. Go back up into a pike and come down bringing the other knee into your chest. Keep alternating for 30 seconds.
Plank Hold (isometric) - all you're doing here is holding a high plank for 30 seconds.

2. Side Crunches, right (dynamic) - lie down on your left side, legs and bottom arm extended, top arm bent with hand behind your ear. From here, crunch up to the side bringing either one or both knees up to meet your elbow in the middle. Extend back down. Keep crunching for 30 seconds. Trainer Tip: if you want to make that even more challenging, do a side V up keeping both legs straight.
Side Extension Hold (isometric) - stay on that same side and extend both arms and legs out straight hovering them slightly above the floor. Hold that position for 30 seconds.

3. Twisted Slow Mountain Climbers (dynamic) - start in a high plank (push up position) and slowly alternate bringing one knee to the opposite side of your chest, squeezing your abs as you bring it in. Place that foot back down and bring the other knee in, squeezing your abs. You're not running here like regular mountain climbers, you're just "stepping." Keep going for 30 seconds.
Star Plank Hold (isometric) - similar to the superman plank, but your arms and legs are extended out at 45˚ angles instead of straight in front/back. Hold that position for 30 seconds. Trainer Tip: if that's too much for you, hold a regular plank.

4. Side Crunches (dynamic) + Side Extension Hold (isometric), left

Remember to go through that once more for the full workout! Your abs are sure to be on FIRE when you're done!

Readers: chat with me! What's your favorite bodyweight ab exercise? How about with equipment? Do you incorporate both dynamic and isometric exercises into your workouts? What's your fave?