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The No-Joke Ab Workout That Only Takes 5 (Brutal) Minutes

All right, ladies. You've planked, you've twisted, you've mountain climbed—but the real ab workout starts here. These moves truly put your ab challenge efforts to the test. "These exercises activate your entire core, and we've added equipment to up the intensity even more," says Lauren Williams, Tone House trainer and creator of the whole 30-Day Ab Challenge.

You know the drill by now, but this week is a little different (and longer!): You'll do ab exercises on Sunday, Monday, Wednesday, and Thursday. Which ab exercises, you ask? Kneeling medicine ball chops, kneeling medicine ball slams, resistance band bicycle presses, resistance band plank jacks, side plank leg lifts, and bicycles (Williams breaks 'em down in the video).

For the cardio days, of course we added burpees to the mix (happy Tuesday!), followed by your standby sprints on Friday. Saturday used to be your rest day—not this week. (Don't worry, you're almost there!) On Saturday and Sunday (the 29th day), you'll repeat the same ab sequence you did at the beginning of the week. Then, on Monday, you'll do every ab exercise in the 30-Day Challenge for 30 seconds. Does it sound like more work than Week 1, Week 2, and Week 3? It is. #SorryNotSorry.

Done? Remember, maintaining the momentum is key. Work our top 10 ab exercises and this intense ab workout that carves crucial core muscles into your routine for long-lasting results.











5-Minute Week 4 Breakdown

Kneeling Medicine Ball Chops

  • Come into a tall kneeling position, squeezing your glutes.
  • Hold a medicine ball down by your right hip, then lift it across and up over your left shoulder.
  • Repeat for 50 seconds.

Kneeling Medicine Ball Slams

  • Start in tall kneeling position, with the medicine ball on the floor on one side.
  • Bring the ball up and overhead, slamming it down on the opposite side. Alternate sides.
  • Repeat for 50 seconds.

Resistance Band Bicycle Presses

  • Flip onto your back in a tabletop position and wrap the resistance band around your feet. Rest back with your hands behind your head, elbows out.
  • Begin to reach each elbow toward the opposite knee, extending the other leg out and alternating in bicycle style. Press the band to push your feet away from you.
  • Repeat for 50 seconds.

Resistance Band Plank Jacks

  • Come into a straight-arm plank position, hands below your shoulders and a resistance band wrapped around your ankles.
  • Bring the feet closer together, then jump out to a wide stance and back in again.
  • Repeat for 50 seconds.

Side Plank Leg Lifts

  • Come into a side plank position with one arm straight underneath your shoulder, the other on your top hip, legs straight and feet stacked.
  • Lift your top leg slowly up and down.
  • Repeat for 50 seconds.


  • Return to bicycle position on your back in tabletop.
  • Press each leg outwards while alternating your elbows touching your knees.
  • Repeat for 50 seconds.



Kiera Carter

Kiera Carter is the executive web editor of FITNESS and SHAPE. She's also a New York University alum, Brooklyn resident, and half marathon lover.  More →

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