Twin Studies in Sport and Physical Performance

Abstract

In his recent book Dr. Roy J. Schepherd states that:“Further information of genetic effects is likely to be derived from comparisons of identical (monozygotic) and fraternal (dizygotic) twins. Gedda (1961) has already shown that identical twins are more likely to have a similar interest in sports than are fraternal twins. It would be interesting to carry out comparisons of maximum oxygen intake and other objective measurements of endurance fitness on the two classes of twins, but this crucial experiment has yet to be completed”.We are very glad to be able to announce here that Dr. Schepherd's wish is being fulfilled within the scope of a wider research project undertaken jointly by the Gregor Mendel Institute for Medical Genetics and Twin Research and the Italian Olympic Committee's Institute of Sports Medicine under the auspices of the Italian Sports Medicine Federation.The studies we have undertaken aim to assess the respective roles of genetic and environmental factors as related to selection and training in sports and physical education.The twin method affords, through a comparison of MZ and DZ within-pair concordances, an assessment of the degree of genetic conditioning in any individual trait.It is quite obvious that the possible influence of training on any given trait is inversely proportional to the degree of genetic conditioning of the same trait.If a given trait, required for a certain type of activity, is completely or almost completely conditioned by the genotype, we should seek those who have inherited it from their parents without wasting time and effort in useless training sessions.As we can see, the scientific information we are seeking has great practical importance in the selection and training of athletes in every single field of sports and physical education.

Genetic Influences on Muscle Strength, Lean Body Mass, and Bone Mineral Density: A Twin Study

“…Although muscle fiber composition apparently has a major genetic component, muscle fiber area is related to training at all ages,28 and muscle strength will therefore be defined by a combination of genetic and environmental factors. Our heritability estimate for grip strength of 0.30 is consistent with results of smaller twin studies in adult men and in children 16 , 29…”

Advances in selected areas of human work physiology

“…Vital capacity and total lung capacity in humans are highly related to body size. Several twin studies have suggested that there is significantly more variation between dizygotic twins (DZ) than between monozygotic twins (MZ) for vital capacity (Venerando and Milani-Comparetti, 1970;Arkinstall et al, 1974;Pirnay et al, 1975;Man and Zamel, 1976). This is generally interpreted as a significant genetic effect for the measured phenotype.…”

Heritability estimates of muscle strength‐related phenotypes: A systematic review and meta‐analysis

“…[18][19][20][21] Heredity of muscle strength-related phenotypes was first examined in 1970. 22 In the 1970s, early twins studies calculated heritability estimates based on difference monozygotic (MZ) and dizygotic (DZ) twins for the correlation coefficient of muscle strength-related phenotypes. 14,15 This is based on the premise that MZ twins are ascribed equal genetic information; meanwhile, the genetic information between DZ twins is the same as that between siblings; that is, on average, they share about 50% of their genetic information.…”