An athlete’s heredity characteristics are those genetically inherited from their parents, including gender, race, muscle type and somatotype (body type).

Gender is heredity and affects levels of hormones, particularly testosterone, responsible for muscle growth and development. As such, males tend to be more muscular, stronger and more powerful than females. This difference has caused the labelling of some sports as “male” or “female”, though these labels are not justified. Gender tends to have little affect on competition as sports are normally gender specific, but it does affect performance, with males performing better in sports requiring speed, power and strength such as swimming and rugby league.

Race is also heredity and particular races can have specific genes that make them more suited to particular sports. Often dark ethnic groups have higher percentages of fast twitch muscle fibres and are taller than other lighter races (though this is not always the case). An example of this is the domination of dark people in the 100m finals, and basketball. Though obviously darker ethnic groups can also be suited to other sports such as long distance running. In comparison, white Caucasian ethnic groups tend to be more suited for sports such as, swimming and hockey. Though this can also be a product of social upbringing, like South America and soccer.

Muscle type is heredity and cannot be changed. The relative balance or percentage of each type of muscle fibre will suit athletes to particular sports. Athletes with high levels of type II, fast twitch fibres are more suited to fast, powerful sports, such as: 100m sprint, rugby league or shot-put. Athletes with high levels of type I, slow twitch fibres on the other hand, are more suited to longer more enduring sports, such as: marathon running or cross-country skiing. There are other sports that require a balance of both and suit athletes who have a good number of both types of fibres, these include: soccer and Australian Rules Football.

Similarly somatotype can help determine an athlete’s suitability for particular sports. Endomorphs, carry more weight and tend to hold the weight lower have advantages in sports such as rugby union or blocking in American Football. Mesomorphs tend to be very muscular and have low body fat and are best suited to sports such as Australian Rules Football, bodybuilding and rowing. Ectomorphs are skinny and are best suited for sports such as long distance running, high-jump and horse racing. Differences in height will also affect which sports the athlete is best suited to. Tall athletes tend to suit sports such as netball, basketball or volleyball, while shorter athletes are more suited for horse racing, gymnastics, and bike riding.

People can acquire skills quickly and perform them well, while not being suited for the sport, such as a short high-jumper who performs the skill well, but does not jump as high as a taller person, more suited to the sport.