Three Types of Exercises

There are stretching exercises, strengthening exercises, and aerobic (or endurance) exercises. You need to know the difference.

Strengthening exercises are the least important, and you can do them or not. These are “body-building” exercises, which are often performed just for cosmetic results. They build more bulky muscles. Squeezing balls, lifting weights, and doing push-ups or pull-ups are examples of strengthening exercises. These exercises can be very helpful in improving function in a particular body part after surgery (for example, knee surgery) where it is necessary to rebuild strength. Otherwise, do them only if you want to increase your strength. It should go without saying, but you should never use steroids as part of a strengthening program; by so doing, you will damage your future health.

Stretching exercises are designed to keep you loose. These are a bit more important; everyone should do some of them, but they don’t have many direct effects on health. As you age, you want to be careful not to overdo these exercises. Toe-touching exercises, for example, should be done gently. Do not bounce. Stretching should be done relatively slowly, to the point of early discomfort and just a little bit beyond.

Stretching exercises, however, can be therapeutic in certain situations. If you have a joint that is stiff because of arthritis or injury, if you have just had surgery on a joint, or if you have a disease condition that results in stiffness, then stretching is usually an important part of the therapeutic solution. Remember that there is nothing mysterious about the stretching process. Any body part that you cannot move through its full, normal range of motion needs to be repeatedly stretched. This enables you to slowly, often over weeks or months, regain motion of that part.

For most people, however, stretching exercises are useful mainly as a warm-up for aerobic (endurance) exercise activity. Gently stretching before you begin endurance exercise is important for three reasons: (1) It warms up the muscles, (2) it makes them looser, and (3) it decreases the chances of injury. Stretching afterward can help prevent stiffness.

Aerobic (endurance) is the key to fitness. This is the most important kind of exercise. The word “aerobic” means that during the exercise period, the oxygen (air) that you breathe in balances the oxygen that you use up. During aerobic exercise, a number of body mechanisms come into play. Your heart speeds up to pump larger amounts of blood. You breathe more frequently and more deeply to increase the oxygen transfer from the lungs to the blood. Your body develops increased heat and competencies by sweating to keep your temperature normal. You build endurance.

During endurance exercise periods, the cells of the body develop the ability to extract a larger amount of oxygen from the blood. This increases function at the cellular level. As you become more fit, these affects persist. The heart become larger and stronger and can pump blood with each stroke. The cells can take up oxygen more rapidly. As a result, your heart rate when you are resting doesn’t need to be as rapid. This allows more time for the heart to repair itself between beats.