Even everyday activities require upper body strength, especially in the biceps (which help bend the arms), the triceps (which straighten the arms) and the deltoids (which lift the arms). The traditional push-up is an excellent way to strengthen all these muscles at once. And for an extra challenge, try doing it with a yoga block.

1 Start on all fours, positioning a yoga block just beneath your frontal hip bones. Now place your hands directly below your shoulders. Curl your toes under and straighten your knees. Reach back strongly through your heels and reach forward with the crown of your head. Think of forming a straight line with your whole body.

2 Keeping your elbows close to your ribs, slowly bend your elbows until your upper arms are parallel to the floor and your hips are just touching the block. Don't let your shoulders creep up toward your ears. Keep your abdominals pulled in to support your back. Hold for a few breaths then push back up. Repeat 3 to 4 times.

This article originally appeared in the Los Angeles Times in the "Good Form" feature of the Health Section. "Good Form" is updated with a new Karen Voight article each Monday.