Medicine-Ball Mountain-Climber

1. Start in a high plank position with both hands on a medicine ball beneath your chest. Your arms should be straight, and your body should form a straight line from your head to your heels.

2. Engage your core, ensuring your back is flat and not arched or sagging.

3. Start the movement by driving one knee in towards your chest, with the toe just off the ground.

4. Return that leg back to the starting position while simultaneously driving the opposite knee in towards your chest.

5. Continue alternating legs at a rapid pace, like running in place while maintaining your hands on the medicine ball.

6. Breathe steadily throughout the exercise, and keep the core engaged to prevent the hips from bouncing up and down.

The medicine ball adds an element of instability to the mountain climber, requiring additional work from the core muscles to stabilize the body throughout the movement. It can be performed as a timed exercise (e.g., 30-60 seconds) or in sets of a certain number of repetitions per leg.

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