Skip to content
Crucible Fit
  • The Crucible
  • The Week
  • Programs
  • Train Your Way
  • Pricing
Get Crucible
  • The Crucible
  • The Week
  • Programs
  • Train Your Way
  • Apple Watch
  • Pricing
  • FAQ
  • Training Guides
Get Crucible
Crucible Fit

A daily functional fitness test for iPhone, Apple Watch and Android. Stations, reps and the Crux, sized to your readiness and your kit.

Download on the App StoreGet it on Google Play

Crucible Fit

  • The Crucible
  • The Week
  • Programs
  • Train Your Way
  • Apple Watch
  • Pricing

Explore

  • Training Guides
  • Exercise Library
  • FAQ
  • Press
  • Support

Legal

  • Terms and Conditions
  • Privacy Policy
  • Consumer Health Data Notice

CRUCIBLE FIT™ and Crux by Crucible Fit are trademarks of Crucible Fit, LLC.

© 2026 Crucible Fit, LLC. All rights reserved. Apple, the Apple logo, iPhone and Apple Watch are trademarks of Apple Inc., registered in the U.S. and other countries. App Store is a service mark of Apple Inc. Google Play and the Google Play logo are trademarks of Google LLC.

  1. Home
  2. /
  3. Exercises
  4. /
  5. Core & Abs
  6. /
  7. Standing Under Knee Clap

Exercise guide

Standing Under Knee Clap

  • Intermediate
  • Compound
  • Timed hold
  • Lower legs
  • Upper legs
  • Waist

The Standing Under Knee Clap is a dynamic core exercise that improves balance, hip mobility, and abdominal strength by combining a high knee drive with a rhythmic torso crunch.

Reviewed by the Crucible Fit team · Updated June 2026

Watch the Standing Under Knee Clap demonstrationVideo and instructions for every movement are in the Crucible Fit app.

Muscles worked

Primary

  • Calves
  • Glutes
  • Hip flexors
  • Quadriceps

Secondary

  • Abs
  • Hamstrings
  • Obliques

Equipment

  • Body weight

Setup

  1. Stand tall with your feet hip-width apart and your core engaged.
  2. Extend your arms out to your sides at shoulder height, palms facing down.
  3. Shift your weight slightly onto one leg while maintaining a soft bend in the knee.

How to do it

  1. Exhale and drive one knee toward your chest while swinging both arms down to clap your hands together underneath the raised thigh.
  2. Perform a slight crunch with your upper body to meet the knee, focusing on contracting the abs and obliques.
  3. Inhale as you return to the starting position, lowering your foot and extending your arms back to the sides.
  4. Immediately repeat the movement on the opposite leg, alternating sides with a steady, rhythmic tempo.

Form checklist

  • Drive the knee as high as possible to minimize excessive rounding of the spine.
  • Keep the standing leg stable and the calf engaged to maintain balance.
  • Ensure the clap happens fully under the leg, not in front of the knee.
  • Maintain a controlled descent of the leg to avoid slamming your foot on the floor.

Pro tips

  • Focus on the 'crunch' sensation in your lower abs as the knee rises to maximize muscle recruitment.
  • Keep your chest proud and gaze forward between reps to prevent losing balance.

Make it harder

  • Increase the speed of the movement to add a cardiovascular element and challenge coordination.
  • Incorporate a small hop on the standing leg during the clap to increase power output in the calves and quads.

Frequently asked

What muscles does the standing under knee clap work?
The standing under knee clap primarily targets the calves, glutes, hip flexors, and quadriceps, and also works the abs, hamstrings, and obliques as secondary muscles.
What equipment do you need for the standing under knee clap?
The standing under knee clap requires no equipment — just your body weight.
Is the standing under knee clap good for beginners?
The standing under knee clap is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.

Related exercises

  • Dumbbell One Arm Snatch LeftIntermediate · calves, glutes, hamstrings, hip flexors, and quadriceps
  • Band DeadliftBeginner · calves, glutes, hamstrings, quadriceps, and trapezius
  • Barbell Hang CleanAdvanced · erector spinae, glutes, hamstrings, hip flexors, and quadriceps
  • Barbell Hang Clean Below The KneesAdvanced · calves, glutes, hamstrings, quadriceps, and trapezius

Train it with Crucible Fit.

Every movement in this library is in the app with video and instructions, ready for your own sessions on the days between Crucibles. Your first Crucible is on us.

Download on the App StoreGet it on Google Play

See how a Crucible works