Waist Exercise · Body Weight

Bottoms-Up form demonstration - targeted for Abs Waist workouts

Bottoms-Up

The bottoms-up is a reverse-crunch-style movement where the hips lift off the floor rather than the shoulders curling up, putting more emphasis on the lower abs and hip flexors working together with the obliques for stability. It's a common progression once basic crunches feel too easy, since controlling the hips through a full lift and lower is harder than it looks. Momentum from swinging the legs is the main way people cheat the rep — a slow lower is where the real work happens.

Go to the movement steps
Category
Waist
Equipment
Body Weight
Target
Abs

Exercise reference published by PlanWorkouts; see our editorial standards.

How to Do the Bottoms-Up

  1. Lie flat on your back with your legs extended and your arms at your sides.
  2. Bend your knees and draw them toward your chest, keeping your feet off the ground.
  3. Engage your abs and lift your hips off the ground, bringing your knees toward your head.
  4. Pause briefly at the top, then slowly lower your hips back down to the starting position.
  5. Repeat for your desired repetitions, keeping constant tension on the working muscle throughout.

Quick Exercise Facts

Movement Type Targeted (Isolation)
Equipment Body Weight
Main Muscle Abs
Supporting Muscles Hip Flexors

Target Muscle Activation

Abs — Main Target
Obliques — Supporting
Stabilizers — Balance & Core

Recommended Sets & Reps by Goal

Build Muscle & Size 3 – 4 Sets × 10 – 15 Reps

Moderate weight · 60s rest

Tone & Shape 3 Sets × 15 – 25 Reps

Lighter weight · 30–45s rest

Form & Control 2 – 3 Sets × 12 – 15 Reps

Lower slowly for 3 seconds · 60s rest

Technique & Form Tips

Focus on trunk flexion, rotation, or anti-movement stability as required by your specific variation. Maintain the suggested pelvic and spinal orientation to keep tension focused on the abdominal area throughout each repetition or hold.

Common Mistakes to Avoid

  • Pulling the neck: For crunch variations, avoid pulling the head forward with your hands; follow the demonstrated arm and head position.
  • Lower back arching: Keep the spine controlled to prevent the lower back from hyperextending under the load.
  • Excessive speed: Perform movements with deliberate control rather than relying on rapid, bouncing motions.

How to Breathe During This Exercise

Maintain a steady breathing rhythm during the effort.

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Comfort and Control

Choose a load and range you can control. Stop if the movement causes pain. If discomfort persists, stop and ask a qualified professional about an appropriate exercise and range.

General guidance: Mayo Clinic on weight-training technique. Follow the specific movement steps above for this variation.

Muscles Worked

The Bottoms-Up mainly targets your Abs, with your Obliques helping support the movement, along with your Hip Flexors.

More Waist Exercises

More Abs Exercises

Equipment Alternatives

Don't have body weight? These target the same abs with different equipment.

FAQ

What muscles does the Bottoms-Up work?
The Bottoms-Up mainly works your abs. It also helps strengthen your obliques and hip flexors. Using good, smooth form makes sure you work the right muscles and avoid unnecessary strain on your joints.
What equipment do I need for the Bottoms-Up?
You do the Bottoms-Up with no equipment — just body weight. Make sure your equipment is set up safely before starting. If you work out at home or have limited gear, check out our alternative exercises below.
What form mistake should I watch for on the Bottoms-Up?
One mistake to watch for is pulling the neck: For crunch variations, avoid pulling the head forward with your hands; follow the demonstrated arm and head position.. Use a comfortable range and a controlled return; reduce the load if you cannot maintain the demonstrated setup.
How many sets and reps should I perform on the Bottoms-Up?
To tone and grow muscle, do 3 to 4 sets of 10 to 15 smooth reps with 60 seconds of rest, focusing on a full stretch and squeezing the muscle at the top of each rep.
What's a good alternative to the Bottoms-Up?
The Assisted Hanging Knee Raise trains your abs with assisted and a similar movement pattern. Review its form guide before substituting it, since setup and range of motion can differ.
Community Q&A

Questions & Form Advice: Bottoms-Up

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