The relative contributions of genetic and environmental components in the variability of anthropometric measurements were studied in 54 twin pairs. Thirty pairs of monozygotic (MZ) and 24 pairs of dizygotic (DZ) twins were investigated to estimate the role of genetic, environmental and hereditary factors determining anthropometric measurements comprising body weight, standing height, sitting height, knee height, arm span, chest circumference and biiliac diameter. Within-pair variance for all the measurements were significantly smaller (p < 0.05-0.01) in MZ twins than in DZ twins of both-sex twin group. Within-pair correlations for those measurements were higher (p < 0.01) in both MZ and DZ twins. Correlation values were, apparently, higher more in MZ than in DZ twins. Besides, all the measurements are highly heritable components and heritability estimates ranged 40%-91%. When both MZ and DZ twin pairs of both-sex population were classified, based on age and sex, into different sub-groups interindividual variabilities were altered to a certain degrees. These data state that anthropometric measurements are influenced by genetic factors than environmental factors and besides, age and sex are possibly associated, to some extent, with the genetic influence upon anthropometric measurements.

Thirty pairs of monozygotic (MZ) and 20 pairs of dizygotic (DZ) twins, of both sexes, were studied to estimate the role of genetic and environmental factors determining fitness measurements comprising vital capacity (VC), vertical jump, flexibility, agility, and PFI score. Intra-pair variances for VC, vertical jump, and heart rate were significantly smaller (p < 0.05-0.01) in MZ than in DZ twins, where values for flexibility, agility, and PFI were insignificant. Intra-pair correlations for VC, vertical jump, and heart rate were higher (p < 0.01) in MZ than in DZ twins where the opposite was found in the case of flexibility and agility. The correlation value for PFI was higher in both MZ and DZ twins. Following adjustment for physical characteristics including age, weight, and height, none of the results of all the residual fitness measurements were similar to the unadjusted values. Both unadjusted and residual variables with smaller intra-pair variances showed higher heritability estimates. These results suggest that VC, vertical jump, and heart rate are influenced more by genetic factors than environmental factors where the inverse is true of flexibility, agility, and PFI. Thus, the genetic and environmental influence of all the fitness measurements, except VC, more or less depend upon physical characteristics in this study.