Rotating Mountain Climber.

Make every rep count.

1. 01

   Start in a strong high plank: hands directly under shoulders, legs long, core braced, and body in a straight line from head to heels.

2. 02

   Keeping your hips as level as possible, bring one knee across your body toward the opposite elbow, letting your hip flex to about 90°.

3. 03

   Pause briefly under control, then slowly extend the leg back to the plank without letting your lower back sag.

4. 04

   Alternate sides (or complete all reps on one side), maintaining steady breathing and controlled tempo throughout.