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  5. Chest
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  7. Knee Tap Sky Reach

Exercise guide

Knee Tap Sky Reach

  • Intermediate
  • Compound
  • Rep-based
  • Back
  • Chest
  • Lower arms
  • Lower legs
  • Shoulders
  • Upper arms
  • Upper legs
  • Waist

The Knee Tap Sky Reach is a dynamic full-body movement that improves core stability, shoulder mobility, and coordination by combining a high knee drive with a vertical reach. It effectively engages the obliques and deltoids while challenging balance and lower-body control.

Reviewed by the Crucible Fit team · Updated June 2026

Watch the Knee Tap Sky Reach demonstrationVideo and instructions for every movement are in the Crucible Fit app.

Muscles worked

Primary

  • Abs
  • Calves
  • Deltoids
  • Obliques
  • Pectorals

Secondary

  • Rhomboids
  • Serratus anterior
  • Trapezius

Equipment

  • Body weight

Setup

  1. Stand tall with your feet hip-width apart and arms relaxed at your sides.
  2. Engage your core and maintain a neutral spine with your gaze fixed forward.
  3. Distribute your weight evenly across both feet to establish a stable base.

How to do it

  1. Simultaneously drive your right knee toward your chest and reach your left arm straight up toward the ceiling.
  2. Exhale as you tap your right knee with your right hand, focusing on a strong core contraction.
  3. Inhale and lower your leg and arm back to the starting position with controlled tempo.
  4. Repeat the movement on the opposite side, alternating sides in a fluid, rhythmic motion.

Form checklist

  • Keep your chest lifted and avoid leaning forward or rounding your back.
  • Drive your knee high enough to feel your lower abdominals engage.
  • Fully extend the reaching arm to maximize deltoid and oblique activation.
  • Maintain a slight bend in the standing leg to protect the knee and improve balance.

Pro tips

  • Focus on 'growing tall' through your spine during the reach to maximize the stretch and engagement of the obliques.
  • Squeeze the glute of the standing leg at the peak of the movement to enhance single-leg stability.
  • Synchronize the tap and the reach to occur at the exact same time for better neuromuscular coordination.

Make it harder

  • Perform a calf raise on the standing leg as you reach to increase calf activation and balance difficulty.
  • Increase the speed of the transitions to add a cardiovascular element while maintaining strict core control.

Frequently asked

What muscles does the knee tap sky reach work?
The knee tap sky reach primarily targets the abs, calves, deltoids, obliques, and pectorals, and also works the rhomboids, serratus anterior, and trapezius as secondary muscles.
What equipment do you need for the knee tap sky reach?
The knee tap sky reach requires no equipment — just your body weight.
Is the knee tap sky reach good for beginners?
The knee tap sky reach is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.

Related exercises

  • Alternate Front Kick In Place With Arm CirclesBeginner · abs, calves, deltoids, and pectorals
  • Body Open Cross FeetBeginner · calves, deltoids, and pectorals
  • InchwormIntermediate · abs, hamstrings, obliques, pectorals, and trapezius
  • Parsva Balasana Yoga PoseBeginner · abs, erector spinae, lats, obliques, pectorals, 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.

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