Slideshow: The 30-Minute Workout Routine

Think you don't have time to work out? You do. It's the intensity of your workout that's key. A short–burst, high–intensity workout boosts your metabolism and tones muscles. Get moving with this 30–minute "quickie" routine that includes cardio and resistance training.

If you're new to exercise, a man over age 45 or a woman over age 55, or have a health problem, check with your doctor before starting a fitness program.

If you're new at this, get started with a beginner version of squats using an exercise ball. Stand against a wall with the ball at your lower back, feet hip–width apart and out in front. Keeping your body upright, slowly lower your body by bending at the hips and knees, dropping glutes toward the floor; slowly move back to the starting position. Do 10 times.

Once you're ready, try squats without an exercise ball. For good form: Keep your feet shoulder-width apart and your back straight. Bend your knees and lower your rear as if you were sitting down, keeping your knees over your ankles. In the "wrong" picture, notice how the knees are too far forward. To target more muscle groups in less time, add an overhead press at the same time. With a dumbbell in each hand, rise from the squat position and push weights overhead, palms out. Do 10 times.

Standing with feet hip–width apart, take a big step forward with one leg, then lower your body toward the floor, front knee aligned with ankle, back knee pointing to the floor. Return to the starting position, and repeat by stepping forward with the other leg. For more challenge, hold a free weight in both hands and complete the lunge with a rotation in the torso, twisting the body toward the forward leg. Do 10 times on each side.

To do a deadlift holding a bar or free weights, stand up straight with feet hip–width apart. Bend at your hips, moving the hips backward as you lower your upper body parallel to the floor. Keep your legs straight without locking the knees, and keep the back level and the spine in neutral. Lower the weight to just below your knees, then slowly return to the starting position. Do 10 times.

The bridge works the glutes (butt), hamstrings, and core. Lying on your back with knees bent and feet hip-width apart, peel your spine off the floor, starting at the tailbone, forming a diagonal line from knees down to shoulders. Slowly return to the starting position. For an extra challenge: Target your triceps by holding light weights, lifting your arms toward the ceiling as you raise your hips. Bend your elbows to lower the weights towards the floor. Do 10 times.

Let's move to the upper body. Push-ups strengthen the chest, shoulders, triceps, and core muscles. Starting on all fours, place hands a bit wider than your shoulders. Place toes on the floor, creating a smooth line from shoulders to feet. Keeping core muscles engaged, lower and lift your body by bending and straightening your elbows. Too hard? Place knees on the floor instead of toes. To boost the workout, add an exercise ball under the hips, knees, or feet. Do 10 times.

For a less demanding exercise than push-ups to help build and tone your chest muscles, you can try the chest press with weights. Lie face-up on a bench, with knees bent and feet on the floor, spine relaxed. Press a bar or dumbbells from your chest toward the ceiling. Extend your arms but don’t lock the elbows, and move slowly in both directions, keeping shoulder blades on the bench. For an extra challenge, do the chest press with your head and upper back on an exercise ball. Do 10 times. 

The bent-over row works all the major muscles of the upper back as well as the biceps. Begin the exercise in a bent-over position with your back flat, one knee and one hand on the same side of the body braced on a bench. Hold a free weight in the other hand with arm extended. Lift the weight toward the hip until the upper arm is just beyond horizontal, see right. Then slowly lower weight to the starting position. Do 10 times.

A shoulder press works the shoulder muscles and can be performed standing or seated. For extra back support, use a bench with a back rest. Begin with elbows bent and weights at shoulders. Slowly reach toward the ceiling, keeping the elbows under the hands and the shoulders away from the ears; slowly lower back to the starting position. Do 10 times.

For the last upper body exercise, do the cable pull down, which works the upper back. Using a cable machine, sitting straight with a neutral spine, grasp the bar with arms extended. Slowly pull the bar down past the face and toward the chest. Only go as far as you can without leaning back, and control the weight on the way back up. Do 10 times.

Lying on your back on the floor, fold knees toward the chest and curl the upper body off the floor. With hands behind head, slowly rotate upper body to the right while drawing the right knee in and reaching the left leg out. Then rotate left and pull the left knee in and extend right leg out. Focus on bringing the shoulder toward the hip (rather than the elbow to the knee), and keep the opposite shoulder off the floor. Do 10 times.

For another abdominal alternative, lie on your side with a bent elbow directly under your shoulder, and use your torso muscles to lift the body up into a side plank. Then lift the hips higher, then back to the plank, then lower. Do as many as you can with proper form, then repeat on the other side. If this exercise hurts your shoulder or neck, lift only your legs, keeping the hips stacked. Your head will rest on your bent arm. 

Before moving on to the cardio portion of the workout, be sure you've completed 20 minutes of resistance training. If you have, now's a good time for a water break to keep your body well-hydrated. If you haven't, go back and start the circuit over again until you reach the 20 minute goal.

Vary the intensity during your cardio workout. Use intervals, taking about a minute to get from moderate speed to intense. Whether you're on the stair-stepper, the elliptical trainer, or the treadmill, do:

• 30 seconds of the highest speed you can tolerate, then 30 seconds of normal speed.
• Then 30 seconds of the stiffest resistance you can handle, then 30 seconds of normal.

Keep moving back and forth between speed and resistance until you've completed 10 minutes.

Do this 30-minute workout routine every other day, or do it two days in a row if that's better for your schedule. These are not hard-core exercises where you need more rest to recover.