We all know that aerobic exercise burns fat. But plain ordinary aerobics can get very boring. Add a new component and work in 30-45 second intervals. You just don't stop; move on to the next exercise. Not only do you burn fat from your overall body, but you can sculpt and shape specific body parts. But it takes working out a certain way.

The good news is you don't need any equipment. Here's an example of how interval aerobics works for three favourite body parts that usually need extra work: Hip, bum, thighs and stomach.

Try it and see! Do the following three exercises without stopping, 15 repetitions each. (This will take about 30-45 seconds, maybe slightly more. Work at your own pace.) Then repeat two more times without resting.

What have you done? You've helped tone your hips, bum, thighs and abs in less than three minutes.

HIP-BUM: Reverse lunge lift - tightens your entire hip-butt area.

Start: Stand with your left leg forward and right leg back, toes facing front, legs about 18 inches apart, arms straight at your side.

Movement: Leaving your left leg in place, and moving your right arm and right leg together, move your right leg forward and raise your right knee as high as possible. At the same time your right elbow is bent and your right hand is facing you about in line with your chest in a salute.

Return to start position and flex your hip-butt area as hard as possible. Repeat until you have done 15 repetitions and then repeat for the other side of your body. Without resting, move to the next exercise.

THIGHS: Standing leg extension - tightens your entire hip-butt area.

Start: Stand with your right knee raised so that your thigh is about parallel to the floor. You may hold onto a chair for balance with your left arm.

Movement: Extend your right foot out as far as possible so that your entire right leg is now parallel to the floor. Flex your right thigh as hard as possible and return to the start position. (Remember start with your right knee still raised.) Repeat the movement until you have done 15 repetitions. Repeat for the other leg and without resting, move to the next exercise.

STOMACH: Bicycle - tightens your entire abdominal area with a side effect of toning the lower butt.

Start: Lie flat on your back with your right leg bent and your left leg nearly straight up.

Movement: Do a bicycle-like movement, keeping your back flat to the mat. But, flex your stomach muscles as hard as possible throughout the movement. Do 15 repetitions for each leg –- a full repetition will include both legs. Without resting, repeat all three of these exercises two more times.