While desire and dedication are critical components of athletic success, it is unrealistic to think that physiological factors are not equally essential for elite performance.
If you watched some of the Olympic Games coverage, you may have observed a commercial that proclaimed desire and dedication are the keys to becoming a champion athlete. While desire and dedication are critical components of athletic success, it is unrealistic to think that physiological factors are not equally essential for elite performance. Let's examine the evidence on what limits and what enhances athletic ability, beginning with inherited physical characteristics. Somatotype Two key components of our body type (called somatotype) are muscle and fat. We are born with a specific number of muscles cells (called muscle fibers) and fat cells. The number of muscle cells does not change, but we can increase the size of our muscle cells through progressive strength training. The number of fat cells does not decrease, but we can increase them with high caloric intakes, especially during the pubertal years. Fat cells become larger or smaller depending on how much fat is stored within them. Some people are born with relatively small numbers of muscle cells and fat cells. Known as ectomorphs, these are typically thin individuals such as those you see in the distance events of track and field (e.g., marathon runners). Other people are born with relatively large numbers of muscle cells and fat cells. Known as endomorphs, these are typically stocky individuals, such as those you see in the throwing events of track and field (e.g., shot putters). Still others are born with a relatively large number of muscle cells and a relatively small number of fat cells. Called mesomorphs, these are the well-defined muscular individuals such as those you see in the sprinting events of track and field (e.g., 100 meter sprinters). Although strength training can increase the size of your muscle cells, it cannot increase the number of your muscle cells. Consequently, your inherited somatotype influences the type of athletic activities for which you are best suited physically. Muscle fiber type We possess two general types of muscle fibers, classified as fast-twitch and slow-twitch. Fast-twitch muscle fibers are larger, stronger and faster than slow-twitch muscle fibers, but they fatigue much more quickly than their slower-contracting counterparts. Olympic athletes in the 100-meter sprint were born with more than 80 percent fast-twitch fibers in their thigh muscles, whereas Olympic competitors in the marathon race were born with more than 80 percent slow-twitch fibers in their thigh muscles. Because most of us were born with about a 50-50 mix of fast- and slow-twitch fibers in our thigh muscles, and because muscle-fiber type is not changed significantly throughout training, it is unlikely that we could ever make the Olympic team in these events. Although training is essential to maximize one's athletic abilities, great sprinters are born with a much higher percentage of power-type muscle fibers, and great distance runners are born with a much higher percentage of endurance-type muscle fibers, giving them a significant advantage for success in these activities. Body biomechanics We can easily observe that Olympic gymnasts are relatively short and Olympic basketball players are relatively tall. However, there are less visible structural factors that impact our mechanical efficiency and force-producing ability. One of these is limb length. Shorter limbs provide a leverage advantage for strength events (such as weight lifting), whereas longer limbs provide a leverage advantage for speed production (such as discus throwing). Another important biomechanical factor is where your muscles attach to your bones. The farther the muscle attachment is from the joint, the greater the strength advantage. For example, your biceps muscle could lift a 50-percent larger dumbbell if it attached to your forearm 1.5 inches rather than 1 inch from your elbow joint. Our genetic characteristics related to muscles and movement mechanics have great influence our athletic performance. However, our inherited cardiovascular capacity is an equally important determinant of our ability to do aerobic activities. It is estimated that endurance exercise training can increase our cardiovascular capacity by about 25 percent, so people born with a higher initial aerobic ability definitely have an advantage in this area. Personal psychological Clearly, genetically determined physical factors have a major influence on athletic performance. However, it seems that an individual's psychological make-up may play an equally important role in athletic success. One of our distance runners at Penn State did not score very well on the physiological assessments, but through great desire and high effort, that runner won the national championship in the 10,000-meter race over more naturally gifted competitors. It is hard to make the Olympic team without specific physiological characteristics, but it is much more difficult to become an Olympic champion without incredible commitment and hard work. Wayne L. Westcott, Ph.D., teaches exercise science at Quincy (Mass.) College and consults for the South Shore YMCA. He has written 24 books on strength training and physical fitness.