Core

Mountain climber

Driving your knees towards your chest from a plank — raises your heart rate and works your core.

Intermediate Includes jumping Exercise mat
Movement diagram for Mountain climber: high plank to mountain climber (knee in)
Original diagram — start and finish positions.

How to do it

  1. Start in a high plank with hands under your shoulders.
  2. Drive one knee towards your chest, then return it.
  3. Repeat with the other leg.
  4. Build up speed only as long as your hips stay level.

Form tips

  • Keep your shoulders over your hands.
  • Quick feet, still body.

Common mistakes

  • Bottom bouncing up and down.
  • Hands drifting forward.

Easier and harder

Make it easier

Do it slowly, stepping each foot in and out, or with your hands on a step.

Make it harder

Go faster, or bring the knee across towards the opposite elbow.

Sources

  1. NHS: Your post-pregnancy body — checked 3 Oct 2026

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