This exercise is an easy way to strengthen your core — the muscles around your stomach and back.
1. Get into the push-up position.
2. Bend your elbows 90 degrees, resting your weight on your forearms and keeping your elbows beneath your shoulders.
3. Form a straight line from your head to your feet.
4. Tighten your abs, lower back and quads to engage your core muscles.
5. Stay in that position for 15 seconds. Over time, try extending the exercise as long as you can. Stop if you feel pain.