To many, that half-hour a day is the most enjoyable, most therapeutic part of your agenda. To others, it's as dreadful as taking out the trash and doing the dishes. Yet, like your household chores, you know it's something you simply must do.

Cardiovascular activity, referred to simply as "cardio," should be as much a part of your body-sculpting endeavors as pulling and pushing those metal plates. As often as you're pumping the iron, you should also be pumping your heart.

Unfortunately, Americans today are more glued to the screen, whether it be the television, Nintendo, or yes, even the Internet. It has been concluded that the majority of Americans have insufficient cardiovascular activity in their daily schedules, thus leading to a cartload of various health problems.

The 30 minutes per day that you should reserve for cardio work should always entail exercises that are enjoyable, manageable, and of course, safe.

So if you're ready to get sweaty, here are a few wise choices:

RUNNING (Outdoors): Believe it or not, this exercise reminds me a lot of Howard Stern. Like the infamous DJ, you either love it or hate it. Beyond question, however, is the simple fact that running is a fantastic way to whip you into shape and provide full cardiovascular fitness. Running is a full-body exercise in which only you channel the motion, resistance, and weight distribution. There are no wheels or cycles doing any of the work for you.

Sometimes, running can actually be too rigorous an exercise and for bodybuilders it's been known to foil some of that hard-earned muscle mass. Also, running can take a considerable toll on your joints, particularly your knees and ankles as well as your abused feet.

TREADMILL: This may seem like the equivalent to a run through the park or the neighborhood, and in a lot of ways, it is. Running is the same vigorous exercise whether done outdoors or in. Yet, the treadmill, because of its smooth rubbery conveyor belt is a lot more merciful on your joints. It doesn't wear and tear your body the way running on the tarred street will. There is no pounding-like effect.

However, the treadmill does not offer the natural variations such as hills and curves which provides for a more rigorous workout on the streets. Also, the fresh air that can fill and expand your lungs is not a benefit from an indoor facility.

STAIRMASTER & STEPPERS: Some people refer to these devices simply as "sweat machines." close by. Stairmasters, whether they're the rotating kind or the step versions, are both excellent methods of losing weight and shedding body fat.

Yet, many fitness experts have concluded that stairs work may be insufficient in your quest to get in shape. For one, the exercise relies solely on lower body movement and tends to abandon the upper torso. Too often, people rest their arms on the bars at their sides, taking some of the resistance (your body weight) out of your legs.

STATIONARY BIKES: When you ride the stationary bike, it feels like you aren't going anywhere. That's because you're not. But whether or not you're making strides with your cardiovascular health is another matter. While these bikes are beneficial in raising the heart level, they also provide far less strain on the knees and back than other methods of cardio and are excellent for toning up the quadriceps.

The workout you'll get from a stationary bike, however, is of the low-impact variety and like the scenery in front of you, it may feel like you're not going anywhere, especially if you've set high fitness goals for yourself.

SWIMMING: Go on and make a splash. This is an excellent cardiovascular activity in that it is a total body exercise and hits the various muscles in the body. The water provides an excellent form of resistance that will get your heart pumping in no time. The benefits for the heart and lungs are endless.

As for the down side? There's only one.

Not every fitness club has a swimming pool.