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Genetic factors in physical activity levels: a twin study
José A R Maia1, Martine Thomis, Gaston Beunen
1Faculty of Sport Sciences and Physical Education, University of Porto, Portugal. jmaia@fcdef.up.pt
American Journal of Preventive Medicine
|July 23, 2002
Summary
Genetic factors significantly influence youth sports participation and physical activity, with a stronger genetic component observed in males. Environmental factors play a more prominent role in females.
Area of Science:
- Behavioral genetics
- Youth physical activity
- Sports science
Background:
- Interindividual variation in youth sports participation and physical activity is substantial.
- Understanding the etiological factors (genetic vs. environmental) is crucial for promoting activity.
Purpose of the Study:
- To estimate the relative contributions of genes, shared environment, and unique environment to sports participation index (SPI) and leisure-time physical activity (LTPA) in youth.
- To investigate sex differences in these etiological factors.
Main Methods:
- A quantitative genetic modeling approach was applied to 411 Portuguese twin pairs (aged 12-25 years).
- Variance components analysis (additive genetics, shared environment, unique environment) was used.
- Sports Participation Index and Leisure-Time Physical Activity were assessed using the Baecke questionnaire.
Main Results:
- Sex-specific genetic and environmental influences were identified for both SPI and LTPA.
- In males, genetic factors explained 68.4% of SPI variance and 63% of LTPA variance.
- In females, genetic factors explained 39.8% of SPI variance and 32% of LTPA variance, with significant contributions from shared (28.4% SPI, 38% LTPA) and unique environments (31.8% SPI, 30% LTPA).
Conclusions:
- Genetic effects significantly contribute to variation in sports participation and physical activity, with greater influence in males.
- Shared and unique environmental factors are particularly important for explaining sports participation and physical activity variation in females.
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