**Exercise**

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Programmed Ability


But even if you train hard every day, you still might not be able to make your muscles perform as well as another person's. Athletes are not just made; they are born, too.

Strength, power and endurance may be due in part to the distribution of fiber types within an individual's muscles. Muscles have a mixture of two basic types of fibers, fast twitch and slow twitch. Fast-twitch fibers are capable of developing greater forces and contacting faster and have greater anaerobic capacity.

In contrast, slow-twitch fibers develop force slowly, can maintain contractions longer and have higher aerobic capacity. Your genes largely determine whether you have more of one kind of muscle fiber or another. Sprinters tend to have more fast twitch fibers.

Marathon runners tend to have more slow twitch fibers. And the rest of us tend to have an equal distribution of both fiber types. It is not clear whether training can change the distribution of fiber types within an individual.


The training to improve strength, power and endurance of muscle performance is called resistance training (for example, free weights, jump-training and isometric training). Resistance training mostly increases the size of muscle fibers (hypertrophy).

It is not clear whether training can increase the number of muscle fibers (hyperplasia). Muscle fibers get bigger by having more muscle protein content, and that is achieved by making new protein and decreasing the rate at which existing proteins are broken down.

These proteins include contractile proteins as well as the enzymes that are involved in various metabolic reactions. By increasing the strength of muscles, resistance training can also increase the power of muscles. Increases in strength, diet and improved cardiovascular performance can increase muscle endurance.

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Finding the Right Diet


You can help your body to exercise better by eating the right foods. You know that muscle metabolism involves the phosphagen system, glycogen-lactic acid system and aerobic respiration.

The major fuels used are glucose and glycogen. So, if you want to do well, whether you are competing or just exercising for well-being, you should try to increase the stores of glycogen in your liver and your muscles.

Athletes eat solid, high-carbohydrate diets (breads, pasta) the night before competition, and liquid, high-glucose diets in the morning before competition. Sports drinks containing glucose are good to drink during competition to replace fluid and help to maintain blood glucose levels.

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Getting More Oxygen Quickly


To become a world-class athlete or to get the most out of your exercise, you want your muscles to get the oxygen they need most efficiently.

To do that you need to increase:

cardiac output
respiration
the amount of oxygen carried by the blood


You can do this by resistance training, possibly in combination with cross-training, training for more than one sport at a time or for multiple fitness components (strength, endurance and flexibility) at the same time.

The main effects of training on the cardiac output appear to be an increase in stroke volume (that is, a larger heart) and a decrease in the resting heart rate. The increased stroke volume allows the heart to pump more blood with each beat. Because there is a limit to the maximum heart rate (180-190 beats/min), then a slower resting heart rate (50-60 beats/min in the trained athlete vs. the normal 70-80 beats/min) allows the heart to have a greater increase in heart rate during exercise.

The greater increase in heart rate during exercise along with the larger volume increases cardiac output and blood flow to working muscle.

Training can help the respiratory system by decreasing the resting rate of breathing, increasing the respiration rate during exercise and increasing the volume of air exchanged with each breath (tidal volume).

These changes allow the lungs to take in more air during exercise. Training can also boost the amount of oxygen that the working muscles take from the blood, which probably reflects the increases in metabolic enzymes.

You have probably heard about runners or cyclists who train in the mountains. This kind of training can actually increase the amount of oxygen carried by the blood forcing the body to develop more hemoglobin in the blood.

Because there is less oxygen in high altitudes, the body responds by producing a hormone called erythropoietin (EPO), which causes the bone marrow to produce more red blood cells and more hemoglobin. Some athletes try to take a shortcut by injecting EPO directly into the bloodstream, but this is a dangerous practice.

The International Olympic Committee has banned the use of EPO because it increases the thickness of the blood, which can lead to circulatory problems such as a heart attack or stroke.

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Train Where You'll Exercise


If you are an athlete and you'll be competing in a place at a high altitude, as during the 1968 Olympics in Mexico City, then training at high altitudes would be helpful.

If the competition is in a hot climate, then gradual periods of training in hot weather can allow the body to increase its efficiency in eliminating heat (increasing sweat production in the most-exposed areas of the body).


The body's reaction to exercise is a carefully orchestrated response of various systems (muscle, heart, blood vessels, lungs, nervous system and skin) designed to meet the needs of working muscles. These systems can be improved by training, thereby improving athletic performance.