Genetic and Environmental Influences on Physical Activity Behavior

Physical activity behaviour emerges from a complex interplay between inherited genetic factors and a spectrum of environmental influences. Twin and family studies have consistently demonstrated moderate to high heritability estimates for habitual exercise and sedentary patterns, indicating that up to half of individual differences in activity levels may be explained by genetic variation. Genome‐wide association studies reveal a polygenic architecture, with dozens of loci each exerting small effects on predisposition to movement or rest. Environmental determinants range from early motor milestones and family climate to socioeconomic status, education and the built environment. Epigenetic modifications, such as DNA methylation in response to exercise exposure, further mediate gene–environment interactions across the lifespan. Mendelian randomisation analyses have begun to disentangle causal pathways, for example demonstrating that higher levels of moderate-to-vigorous activity can reduce body mass index, whereas increased adiposity drives sedentary behaviour. Developmental studies show that the influence of shared environment wanes from childhood to adolescence as genetic factors gain prominence. Understanding these mechanisms has global significance for designing personalised interventions and public‐health strategies that account for both inherited propensity and modifiable contexts.

Research from Nature Portfolio

Recent Mendelian randomisation studies using genetic instruments for leisure-time moderate-to-vigorous activity and screen time have clarified bidirectional relationships with body mass index. Multivariable analyses that incorporate years of schooling reveal that increased physical activity causally lowers BMI, whereas higher BMI drives more sedentary time, and that educational attainment enhances activity levels and mitigates obesity risk. A large multi-ancestry meta-analysis of genome-wide association data, encompassing over 700,000 individuals, identified nearly one hundred genetic loci linked to self-reported activity intensity and sedentary traits. Enrichment analyses point to pathways in the central nervous system and skeletal muscle, including variants in the ACTN3 gene that affect muscle fibre properties. Mendelian randomisation within this framework underscores that the health benefits of lower screen time and higher activity are mediated or confounded by BMI, offering insights into disease prevention mechanisms.

Genetic and Environmental Influences on Physical Activity Behavior publication trend

The graph below shows the total number of articles in genetic and environmental influences on physical activity behavior across all publications each year (not limited to Nature Index journals).

Technical terms

Heritability: Proportion of observed variance in a trait that is attributable to genetic differences among individuals in a population.

Genome-wide association study (GWAS): Unbiased scan of common genetic variants across the genome to identify those associated with a particular trait.

Mendelian randomisation: Analytical method that uses genetic variants as proxies for modifiable exposures to assess causal effects on health outcomes.

Epigenetics: Study of reversible and heritable changes in gene expression that occur without alterations in DNA sequence, often via DNA methylation or histone modification.

Polygenic: Describing a trait that is influenced by many genetic loci, each contributing a small effect to overall variation.

References

1. Distilling causality between physical activity traits and obesity via Mendelian randomization. Communications Medicine (2023).
2. Genetic confounding in the association of early motor development with childhood and adolescent exercise behavior. International Journal of Behavioral Nutrition and Physical Activity (2024).
3. Epigenetic Analysis of the Dopamine Transporter Gene DAT1 with a Focus on Personality Traits in Athletes. International Journal of Molecular Sciences (2023).
4. Genome-wide association analyses of physical activity and sedentary behavior provide insights into underlying mechanisms and roles in disease prevention. Nature Genetics (2022).
5. Mendelian randomization suggests a bidirectional, causal relationship between physical inactivity and adiposity. eLife (2022).