Whether or not you join a fitness club and/or class, take coaching from a personal trainer, or just design your own workout plan, it is important that your workout develops tone, strength and stamina, while keeping you flexible and free of injury. A well-designed workout should never leave you feeling exhausted. On the contrary, you should feel energized and ready to tackle the world.

In this article, I will cover the four essential elements that are necessary for a well-balanced workout: a warm-up, an aerobic activity, a toning session and a cool-down with final stretching.

Spend at least ten minutes warming up to start your workout. A lot of people skip this part of the workout, and I even find instructors who speed through this portion because of time restraints. I can't stress enough that before any activity (even playing golf) it is important to start heating up the body and muscles by moving.

The movement can consist of vigorous walking, lifting the legs, moving back and forth, loosening the head and neck, rotating the shoulders and arms, and combining stretching with your movement. This gets the blood moving and the heart beating faster, preparing your body for the work to come.

In this initial stage, I don't recommend deep, static stretches at the beginning of the workout, but stretches that start to prepare the muscles for the workout. For example, try squats, leg lifts for the calves, a runner's lunge with an up-and-down movement for the hip flexors (you'll feel it in the hip all the way up into the pelvic area), and a ham string (back of the leg) stretch while raising and lowering the toe of the foot. Make sure that you watch the placement of your knees. We never want the knee to extend out over the toe. As long as you can see your foot, you are all right. When we avoid proper warming up, we are just asking for an injury.

Spend at least twenty minutes on aerobic activity. Even though many of the activities you will do aerobically are similar to those you performed while warming up, they are different in their level of intensity. The goals of aerobic activity are to burn fat and calories, get your heart and lungs into shape and build endurance.

You shouldn't ever feel like you are overdoing, but you should work at getting your heart and muscles working in what we call our Training Zone for twenty minutes, three to five times a week. The Training Zone is the minimum and the maximum workout intensity for safe and effective exercise.

One indicator of how hard we are working is the Target Heart-Rate Range. To find yours, subtract your age from 220 and then multiply this number by 60 and 85 percent (.6 and .85). Even though this can vary with levels of fitness, this range can let you know how on-target you are for your age.

To take your heart-rate or pulse, use your first two fingers, never your thumb. Press the fingertips lightly on the carotid artery on the neck and stopping the feet, start counting pulse beats at zero for six seconds. Multiply the answer by ten to get your beats per minute (BPM) heart rate.

It used to be that if a student was above the upper number in their Target Heart-Rate Range, we would admonish, "Slow down, pull back." Today, however, if the student feels fine, it is OK to go above the range for one minute out of every four minutes of aerobic activity. You will be burning carbohydrates along with building cardiovascular fitness, but you must feel energized - not drained.

The heart-rate should be checked during the most intense part of the aerobic exercise and then again before going to the floor (stopping and getting the head down below the heart). The warning here is that if you have been working hard, you don't want to do calisthenics before your heart-rate is down to at least 120 BPM or below.

Toning is the meat of your workout. Because I feel that this is one of the most important elements of a proper workout and one that so many people, especially women, tend to ignore, I will be devoting my next article to the many kinds of muscle work, the frequency and importance of toning, and specific ways to work on toning. Working on toning will bring about the real changes in the shape and tone of your body.

When you first start your calisthenics or working with weights and/or machines, I suggest doing from eight to fifteen repetitions of each exercise with good form - the slower, the better. The toning portion of your workout can either precede or follow the aerobic portion. There are different schools of thought on this, but both have their advantages.

I prefer toning before aerobics and having our full energy to expend, but the advantage of the toning following the aerobics is that we have worked up a good sweat and the muscles possibly move more easily.

Don't skip the most important part of the workout - the cool-down and final stretch! Always do three to five minutes of a slow walk, easy jogging or moving after working hard. These gentle, rhythmic body movements act as a pump to get the blood flowing away from your muscles and back to the heart. This will prevent cramping, dizziness, nausea and sudden changes in blood pressure. Once the heart-rate has slowed, you can move into the final stretching. Don't skip out on the stretching. And, at the end of the workout is the best time to stretch because our muscles are warm and pliable.

Stretching not only helps avoid injuries and muscle soreness, it increases our flexibility (we automatically lose about 10 percent of our flexibility every ten years) and stretching helps us look better when we do it consistently: loose, limber muscles allow us to stand long, strong and tall.

That's your workout for today. Just keep it up and do what you can. You are on your way to life-long fitness!

As always, check with your own healtcare professional before undertaking any diet or exercise program.