One of the best things about doing compound exercises, or moves that recruit more than one muscle group at a time, is that you’re often working your abs and entire core without even realizing it. You don’t always have to feel your abs burning to be working them, which is great. But just like any other muscle group, it’s nice to do some abs-focused work every once in a while.

What you’ll need: You can use a hand towel in the circuit below. You can also use a small exercise ball, or if you don’t have anything on hand, you can do this without anything in your hands.

Moves:
V-up
Figure 8 Crunch
Hollow Hold to Knee Tuck
Butterfly Sit-up
Mountain Climber
Half Burpee Hop

Directions:
Do each exercise for 20 seconds.
Minimize rest in between each move.
Repeat the entire circuit two to three times.
Try your best not to release the contraction in your abs, and move quickly from one exercise to the next to increase the time your abs are under tension. (Of course, if you need a break, take one. A burning sensation in the muscles you’re working is a good thing, but if you feel strain or pain in your lower back, stop and take the time to refocus your form.)
As you get more comfortable with the exercises and start to feel stronger, slowly increase the time to 30 seconds for each move.

V-Up
This exercise gets you firing up all of your abs muscles.

  • Lie faceup with your legs extended and arms extended overhead on the floor, keeping them close to your ears. Hold a towel bunched up in your hands. Squeeze your abs and butt to press your lower back into the ground. This is the 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 the starting position.
  • Continue this movement for 20 seconds.
  • Once you feel comfortable with this move, you can make it harder by passing the towel back and forth from your hands to your legs with each rep.

Figure 8 Crunch
The key here is keeping your shoulder blades off the floor and not resting your legs in between each rep.

  • Place a hand towel on the floor next to you. Lie faceup with your legs in tabletop position (knees bent 90 degrees and stacked over your hips). Use your abs to curl your shoulders off the floor and extend your left leg. Grab onto the towel and hold it underneath your right leg with both hands, one arm on each side of your leg. This is the starting position.
  • Lower your torso an inch as you bring the towel up above you, holding onto it with just your right hand, and extend your right leg and bring your left knee into your chest. Crunch up an inch and as you do, pass the towel underneath your left leg and grab onto it with your left hand.
  • Continue this motion, alternating sides, for 20 seconds.

Hollow Hold to Knee Tuck
To do a hollow hold, you have to keep every inch of your core contracted. The knee tuck movement engages more of the lower portion of the abs.

  • Lie faceup with your legs extended. Hold a hand towel in front of your body with both hands, pulling it from each end so there is tension. Contract your abs and glutes to press your lower back into the ground.
  • Lift your shoulders off the ground and keep your head in a neutral position so that you’re not straining your neck. Squeeze your thighs together, squeeze your glutes, and lift your legs off the ground. This is the starting position, a hollow hold.
  • From here, roll up and bring your knees into your chest so that they meet as you sit up onto your tailbone. Simultaneously, loop the towel over and under your knees, down toward your butt.
  • Then, leaving the towel where it is, lower your torso and legs back down. Make sure to keep both your legs and shoulder blades off the floor to maintain the contraction in your abs.
  • Roll back up and bring your knees back toward your chest as you sit up. This time, bring the towel back up and over the front of your feet and knees. Roll back down to the starting position.
  • Continue this movement for 20 seconds.

Butterfly Sit-up
After a few moves that put some pressure on the hip flexors, this is a great chance to get a good stretch and open up the hips.

  • Lie faceup with the soles of your feet together, knees bent out to the sides. Hold a hand towel overhead with both hands, pulling it from each end so there is tension. This is the starting position.
  • Using your abs, roll your body up until you are sitting upright. Simultaneously, bring your arms forward to reach the front of your toes, while maintaining tension in the towel.
  • Slowly lower back down to the starting position.
  • Continue this movement for 20 seconds.

Mountain Climber

  • Start in high plank, with your palms flat on the floor, hands shoulder-width apart (or wider if that’s how you usually do push-ups), shoulders stacked above your wrists, legs extended, and core engaged. This is the starting position.
  • Engage your core and draw your right knee to your chest.
    3 Return to the starting position and immediately draw your left knee to your chest.
  • Return your left leg to the starting position. That’s 1 rep.
  • Continue to alternate, moving quickly, for 20 seconds.
  • Make sure to keep your core engaged and back flat throughout. If you have to slow down to maintain form, that’s fine.

Half Burpee Hop
This move is also a cardio abs exercise.

  • Start in high plank, with your palms flat on the floor, hands shoulder-width apart, shoulders stacked above your wrists, legs extended, and core engaged. This is the starting position.
  • Engage your abs and glutes and jump your toes in toward your hands, bending your knees and slightly rounding your back just enough so that you get enough height to land on your toes. Your knees should end up very close to your triceps.
  • Then, hop your feet back out to plank position.
  • Continue this movement for 20 seconds.