Aiming to contribute to a better understanding of the nature and characteristics of sport participation and of the factors underlying human performance and adaptation to physical exercise, this study involved (a) the establishment of a specialized twin registry, (b) a questionnaire study, and (c) testing sessions of top level athletes. The general design and procedures of the project are described. A Registry of Italian Twin Athletes (RITA) was developed through a collaborative effort involving 25 sports federations of the Italian National Olympic Committee (CONI). Out of a total of over 1,500,000 registered athletes, some 5,000 pairs of twins practicing sports such as track and field, swimming, tennis, fencing, and cycling, were tentatively identified. A basic questionnaire was devised to address general aspects as well as specific items related to the respondent's respective discipline, and a specific questionnaire was developed for each sport. As a basis for future studies, an application was conducted on the twins registered with the Swimming Federation. The data collected from the completed questionnaires of about 200 twin swimmers indicated a strong zygosity and sex effect on sport selection, with higher prevalence values for identical pairs and for males. The twins appeared to be taller than their counterparts in the general population, as appears to be true for swimmers in general. Both for anthropometry and basic swimming performance analysis, no zygosity effects were found, individual differences being presumably minimized by basic athletic selection factors. For possible genetic effects to be detected, specific and direct testing sessions on high-level performers should be undertaken.
Key Points:• Twin research can substantially contribute to clarify the issue of genetic versus environmental determinants of the individual variability in physical exercise, adaptation, and performance, but large and representative samples are needed.• A population-based registry has been developed, involving over 4000 pairs of twin athletes from 25 sports federations. A questionnaire study has been designed to address general and specific items for each sport, and a first application has been conducted on 200 twin swimmers. Downloaded by [George Mason University] at 00:30 27 December 2014• The data indicate a strong zygosity and sex effect on sport selection, with higher prevalence values for identical pairs and males among the twin swimmers.• With respect to anthropometry, twin swimmers as a group are taller than their counterparts in the general population, as are swimmers in general. Possible zygosity effects are apparently minimized by the common athletic condition. • Individual differences in swimming performance and anthropometry being minimized by basic athletic selection factors, possible genetic effects may only be detected by specific and direct testing on high-level performers.
IntroductionNotwithstanding remarkable progress in various areas of human and sports biology, relatively little is known about the res...