Try this weighted plank

The weighted plank on the BOSU is the final stretch in the abs race. This isometric move will have your entire body shaking after 30 seconds.

To assume the plank position, get down on your hands and feet and place a small weight plate on your lower back. Then, place your hands shoulder-width apart on the BOSU, flat side up. Your elbows will be directly below your chest. Next, carefully and deliberately raise your hips and extend your legs so that your toes are down on the floor.

While in position, tightly contract your abdominals and breathe normally for 30 to 60 seconds.

Tip: If you concentrate on tightening your abs, lower back and glutes, you'll dissuade your hips from dipping and hold the position longer.

Not challenging enough? Lift one leg for 30 seconds and then switch to the other leg for 30 seconds without losing the position. If you're a beginner, stick to the traditional plank on the floor without resistance until it's no longer challenging.

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