Balancing on one leg is a form of resistance training. Every time you take an up elevator, stand on the right leg. Going down, stand on the left. You're forcing the supporting muscles—the quadriceps, the hamstrings and the gluteus maximus [butt]—to work harder, because they are used to doing only 50 percent of the work. Once that becomes easy, bend the standing knee slightly to better challenge the muscles.
Tuck in your abdominal muscles every time you hit the brakes of your car. Hold the contraction until you start moving again. (Hope for fast-changing signals.)
Place a huge Post-it note on your computer monitor: shoulders back! This will help improve your posture, reduce back pain and stress, and take pressure off your neck.
On a roll
I love Resist-A-Balls, those big beach balls you use for exercise. If you have to be at a desk for long stretches, sitting on the ball instead of a chair really helps promote good posture and works your entire core, your abdomen and lower back.
The moment you hit an escalator, tense up your rear end for the whole ride. The glutes are the largest muscles in your body—I know, you already thought that—so squeeze as hard as you can. Just don't make a face.
Get in and out of chairs as slowly as possible. Try for four counts up and four counts down. This works the front of the legs. Ideally, you should tuck in your abs, pull your shoulders back, and tuck your glutes under with a slight forward pelvic tilt. The longer you take, the more you work your leg muscles. Use your hands only if you have to.