SEXUAL DIMORPHISM IN PHYSICAL FITNESS. A MULTIVARIATE STUDY

Abstract

875a The purposes of this study are twofold: (1) to study the impact of body size in the sexual dimorphism of physical fitness (PF) viewed as a whole, a multidimensional trait of the subject, and (2) to identify if the map of differences in fitness of both genders changes along different age groups. The sample size comprises boys (M) and girls (F) from Maputo, Mozambique. The samples per age groups are as follows: 11 years, nM=44, nF=38; 12 years, nM=28, nF=35; 13 years, nM=42, nF=41; 14 years, nM=37, nF=19. Besides height and weight, physical fitness was assessed according to the following tests: agility run, endurance run (12′), handgrip, sit-up, sit and reach. Statistical analysis to test for differences in PF adjusted for body size was multivariate analysis of covariance (MANCOVA) followed by discriminant analysis done in SPSS. In all age groups there were differences in body weight. Exception made for 12 year olds, in all other age groups the multivariate tests showed that after adjustment for body size there are differences in PF (11years, Wilks A=0.66, F=5.44, p=0.00; 13 years, Wilks A=0.52, F=15.71, p=0.00; 14 years, Wilks A =0.52, F=16.73, p=0.00). In 12 year olds and after adjustment for body height and weight there was no significant effect of gender in PF. The mapping of gender differences over this age group is not very different as pinpointed by structural coefficients. In 11 years the importance goes for endurance run and sit-ups; in 13 years is agility run, endurance run and sit-ups; in 14 years is agility run and sit-ups. In conclusion: (1) body weight is a major determinant of gender differences in PF viewed as a whole trait of the subject; (2) adjustments for body weight marked in a similar fashion the sexual dimorphism in the age group of 11 to 14 years;(3) there was no impact of strength (handgrip) in the different mapping of PF in boys and girls; (4) in the 12 year old subjects no dimorphism was evident after size adjustment.