High physical activity/aerobic fitness predicts low morbidity and mortality. Our aim was to identify the most up-regulated gene sets related to long-term physical activity vs. inactivity in skeletal muscle and adipose tissues and to obtain further information about their link with cardio-metabolic risk factors. We studied ten same-sex twin pairs (age range 50–74 years) who had been discordant for leisure-time physical activity for 30 years. The examinations included biopsies from m. vastus lateralis and abdominal subcutaneous adipose tissue. RNA was analyzed with the genome-wide Illumina Human WG-6 v3.0 Expression BeadChip. For pathway analysis we used Gene Set Enrichment Analysis utilizing active vs. inactive co-twin gene expression ratios. Our findings showed that among the physically active members of twin pairs, as compared to their inactive co-twins, gene expression in the muscle tissue samples was chronically up-regulated for the central pathways related to energy metabolism, including oxidative phosphorylation, lipid metabolism and supportive metabolic pathways. Up-regulation of these pathways was associated in particular with aerobic fitness and high HDL cholesterol levels. In fat tissue we found physical activity-associated increases in the expression of polyunsaturated fatty acid metabolism and branched-chain amino acid degradation gene sets both of which associated with decreased ‘high-risk’ ectopic body fat and plasma glucose levels. Consistent with other findings, plasma lipidomics analysis showed up-regulation of the triacylglycerols containing the polyunsaturated fatty acids. Our findings identified skeletal muscle and fat tissue pathways which are associated with the long-term physical activity and reduced cardio-metabolic disease risk, including increased aerobic fitness. In particular, improved skeletal muscle oxidative energy and lipid metabolism as well as changes in adipocyte function and redistribution of body fat are associated with reduced cardio-metabolic risk.

Objective: To determine the association between long-term leisure-time physical activity/inactivity and eating behaviours in twin pairs discordant for physical activity for 30 years. Design: Co-twin control design with cross-sectional data collection using questionnaire on eating habits and 5 d food diary. Differences in eating behaviours between physically active and inactive co-twins were analysed with pairwise tests. Setting: Finland. Subjects: Sixteen same-sex twin pairs (seven monozygotic and nine dizygotic, mean age 60 years) discordant for physical activity, selected from the Finnish Twin Cohort on the basis of physical activity discordance for 30 years, blinded to their possible differences in eating behaviours. Results: The eating habits questionnaire revealed that physically active co-twins more frequently reported that it is easy to eat according to need, whereas overeating and/ or restrictive eating was more common among the inactive co-twins (P 5 0?035). Avoiding calories was more common among the active than inactive co-twins (P 5 0?034). Based on food diaries the physically active co-twins had daily energy intake on average 15?5 kJ/kg higher than their inactive co-twins (P 5 0?030). The active co-twins also had a higher intake of vitamin C (P 5 0?004), total water (P 5 0?044), legumes and nuts (P 5 0?015) and sweets (P 5 0?036), as well as a lower energy-adjusted intake of meat (P 5 0?013). Conclusions: The physically active persons seem to eat more but not necessarily healthier food. However, habitual physical activity may help in eating according to need and in reaching and maintaining a healthy body composition. Therefore, it is necessary to incorporate both dietary and physical activity advice into health counselling.