Which sports promote growth in height? Do naturally tall youths choose to play basketball or volleyball, which are sports where taller players have an advantage? Or conversely, do these sports promote their physical growth, resulting in them becoming taller athletes?
There have been countless reports on the relationship between growth and sports. However, to clarify this issue, it is necessary to collect a sufficient quantity of longitudinal data on the physiques of athletes and an appropriate method of analyzing them, but such an attempt has not yet been undertaken. In light of this, we endeavored to provide a clue to solving this issue by employing the longitudinal data of the 3,421 Japanese athletes and proposing a simple, clear methodology.
The analysis method is to calculate the total growth (height at age 17 minus height at age 6) individually and to analyze the data in terms of gender and sport type. For each player, total growth is plotted against the age‒6 height in a two‒dimensional Cartesian coordinate system, and the distribution of this bivariate data can be used to evaluate the characteristics of each sport. In other words, the height at the time of starting a sport at a young age and the total growth thereafter can be evaluated simultaneously to give an overall view of the effect of that sport on physical growth. Ohsawa (2003) tentatively named this methodology the Growth Grid Method and demonstrated that it can simply and clearly evaluate the physical growth of all races in the world.
The analysis results are as shown in Figures 1 and 2.
1. In the growth of athlete, Height at age 6, boys are 1.9 cm taller than girls, and the difference in the total growth is about 11 cm, whereby boys grow much more than girls. However, gender differences are significantly smaller than in ordinary children.
2. The gender differences of athlete, are clearer when observing various types of sports.
3. Height at the age 6, athletes are already 3.2 cm larger for boys and 2.1 cm for girls than ordinary Japanese children. In boys, the total growth is about the same as that of ordinary Japanese children. Furthermore, in girls, the total growth is larger than that of ordinary Japanese children, and therefore, in girls, the effect of sports on height growth is greater than that of boys.
With regard to boys:
(1) Those in the basketball and volleyball group (Group a) were already ≧121 cm tall at age 6, and the growth was large thereafter also. These sports were chosen by tall boys at age 6, and their growth from that point was significant, as well.
(2) The heights at age 17 were taller, in descending order, for those playing handball, outdoor sports, track and field, swimming, or rugby. This group (Group b) represents sports chosen by relatively tall players both at age 6 and in terms of total growth thereafter (about 55 cm), following the group of basketball players, etc.
(3) Tennis, kyudo, or table tennis was chosen by those who were not so tall at age 6 (≤116 cm tall), but who underwent a large total growth of 55 cm (Group c). It can be inferred that sport has a large effect on growth in this group.
(4) Those who played football or baseball were 117.9～118.8 cm tall at age 6, and their total growth was about 54 cm, positioning them a little shorter than the average among the athletes (Group d).
(5) The judo and kendo group were of average height at age 6, but growth thereafter was not so large (Group e).
(6) Those who chose skiing or badminton were of average height at age 6 but experienced smaller total growth, thus their attained height was smaller (Group f).
(7) Artistic gymnastics (Group g) is a sport played by the shortest, both at age 6 (113 cm) and with the smallest total growth (53 cm). In other words, they were short when they started, and their growth was small, as well.
With regard to girls:
(1) The group of volleyball players (Group a′) was already ≧119 cm tall at age 6,
