If you have one minute...drop and do 10 push-ups (or 20, or 5).
There's a reason that push-ups are every trainer's favorite exercise: They engage muscle groups in the arms, chest, abdomen, hips and legs; they don't require any equipment; they're endlessly adaptable (you can work them into a yoga routine; add jumps to turn them into a cardio move; change your hand position to make them a triceps toner). More important to most of us is the fact that these intense moves get results. "Female clients have told me that they've seen noticeable differences in their arms after doing daily push-ups against a wall or on the edge of a sink," says Shirley Archer, a certified fitness expert and a co-author of Weight Training for Dummies. In as little as two weeks, the exercise should feel easier (no more soreness!), says Archer, and you may see a visible difference in muscle tone after four to eight weeks, depending on your age and your exercise history. Here's how to do push-ups correctly.