Optimum onset period for training based on maximum peak velocity of height by wavelet interpolation method in Japanese high school athletes.

The Wavelet Interpolation Method (WIM) was applied to the longitudinal records of individuals' heights and weights from 6 to 17 years of age (1983 to 1994) in an athlete group (male: 45, female: 50) and a control group (male: 85, female: 85). The criterion of maturity was derived from age at Maximum Peak Velocity (MPV) of height in the control group. Ages at MPV of height and weight were compared between the athletes and control subjects. The WIM was also applied to mean heights from 6.5 to 17.5 years of all the subjects classified by maturation rate in order to derive a model of growth velocity types. Among the athletes, the males were early-maturing and the females tended to be late-maturing. The difference between the ages at MPV of height and weight in males and females was less in the athletes group than in the control group. For the growth velocity model, in the athlete group, three types could be confirmed among the males, and five among the females. By making use of the type models, it was possible to clarify the spans of adolescence as classified by maturation rates, and it was concluded that the period following the age at MPV seems appropriate for the introduction of regular athletic training for each level of maturity.