Physique characteristics of world class male and female african long distance runners

Introduction

It is becoming more important for sport scientists from Africa, who are world leaders in their own field, to do research on the sportsmen and women from Africa. Such research has an impact on scientific coaching, development and assistance for athletes from the African continent. Africa will also be able to develop and elevate itself on the terrain of sport science [1]. The purposes of the study were to describe the physique characteristics (body composition and somatotypes) of world class male and female long distance (LD) runners and to determine by means of a discriminant analysis which variables best discriminated among the male and female LD runners.

Methods

Anthropometric data were collected on 21 male (mean age 24.5  5.52 years) and 19 female (mean age 22.1  3.38 years) LD runners. The subjects were part of the athletes who were measured during the 6th All Africa Games held in Harare, Zimbabwe in 1995 (16 males and 15 females) and at the 8th All Africa Games held in Abuja, Nigeria in 2003 (5 males and 4 females). The anthropometric variables and techniques selected were those described in Norton & Olds [2]. Data analysis was performed using Statistica 6 (StatSoft, Inc., 1984-2003). A forward stepwise discriminant analysis was applied to determine which variables best discriminated among the male and female LD runners. The discriminatory power of the classification functions was established using the jack-knifed classification matrix.

Results

The male runners were significantly (p<.05) heavier and taller than the female runners. As far as body composition is concerned, the male runners (M=7.3%  2.62) had significantly less percentage body fat than the female runners (F=12.8%  1.59), but the males had significantly more muscle mass (M=30.0kg  4.53; F=25.3kg  4.15) as well as skeleton mass (M=7.9kg  0.88; F=6.7kg  0.84) than the female runners. The male LD runners had a mean somatotype of 1.6-2.7-4.2 (mesomorphic ectomorph) and the female LD runners a mean somatotype of 2.0-2.7-4.0 (ectomorph mesomorphy). The only significant difference (p<.05) concerning the somatotypes was between the means of the endomorphic component, where the males were smaller in endomorphy than the females (M=1.6  0.65; F=2.0  0.48). Percentage body fat, sum of 6 skinfolds, percentage muscle mass and mesomorphy were the variables that discriminated best between the male and female LD runners. With the post-hoc analysis 100% of the male LD runners and 100% of the female LD runners were re-classified back into their gender groups.

Discussion/Conclusions

It is concluded that the differences in the physique characteristics of elite African male and female LD runners are likely due to gender and that the comparison of the body composition and somatotypes of the 2 groups of runners clearly show sexual dimorphism. The question arises as to whether or not the sexual dimorphism becomes insignificant when comparing the male and female LD runners by means of proportionality profiles [3], but this will be done in a follow-up study.
Acknowledgement: The contribution of all the research assistants in these studies is publicly acknowledged

References

[1] De Ridder, J.H. et al. (2000). Kinanthropometry in African sports: Body composition and somatotypes of world class male African middle, long distance and marathon runners. (In K. Norton, T. Olds, J. Dollman eds. Kinanthropometry VI. Proceedings of the Sixth Scientific Conference of the International Society for the Advancement of Kinanthropometry. Adelaide, Australia, October 13-16, 1998. Underdale, Australia: ISAK.)
[2] Norton, K. & Olds, T. (1996). Anthropometrica: A textbook of body measurement for sport and health courses. Sydney: University of New South Wales Press. 411p.
[3] De Ridder, J.H. et al. (2003). Sexual dimorphism in elite middle-distance runners: 1995 All-Africa Games (Project HAAGKiP). (In J.H. de Ridder & T. Olds eds. Kinanthropometry VII. Proceedings of the Seventh Scientific Conference of the International Society for the Advancement of Kinanthropometry. Brisbane, Australia, September 7-12, 1998. Potchefstroom, South Africa: ISAK.)