This is an excerpt from Long-Term Athlete Development.
Although growth and development are natural processes, the tempo of the maturation process can vary greatly: “A child with a chronological age of 12 years may possess a biological age between nine and fifteen years” (Borms, 1986, p. 5). The biological differences between a 9-year-old and a 15-year-old are huge, and yet in spite of these biological differences, athletes of the same chronological age are often trained the same way at every age and participate in age group competitions.
When designing a training, competition, and recovery program for an athlete, a coach must take into consideration the age of the athlete. However, other factors that must be taken into consideration require more than just checking the athlete's date of birth. Following are age categories that coaches need to consider when designing sport programs:
- Chronological age refers to the number of years and days that have elapsed since birth. Children of the same chronological age can differ by several years in their level of biological maturation.
- Skeletal age refers to the maturity of the skeleton, which is determined by the degree of ossification of the bone structure. It takes into consideration how far bones have progressed, in size and density, toward maturity.
- Relative age refers to the age variation among children in the same age group, resulting from their different birth dates. Thus, if a grade 1 class is composed of children who will turn 6 years old between September 1 of the school year and August 31 of the following year, then the children with September birth dates will have an approximate one-year relative age advantage over the children born in August of the following year. Conversely, the children with August birth dates will have about a one-year developmental disadvantage relative to their September-born peers. Therefore, the 5 1/2-year-old child going to school with 6 1/2 -year-olds has an 18 percent maturational disadvantage. The relationship of relative age to a variety of performance indicators has been the subject of a number of research reports (Barnsley, Thompson, & Barnsley, 1985; Morris & Nevill, 2006). A participant who is 18 percent smarter, faster, bigger, and stronger than another has a significant advantage in sport.
- Developmental age refers to the degree of physical, mental, cognitive, and emotional maturity. Physical developmental age can be determined by skeletal maturity or bone age. Mental, cognitive, and emotional maturity are then considered to determine developmental age.
- General training age refers to the number of years the person has spent in training and participating in various sports.
- Sport-specific training age refers to the number of years that an athlete has specialized in one particular sport.
With the exception of relative age and developmental age, age definitions and concepts are simple and straightforward. For this reason, this chapter focuses on relative age and developmental age.
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