Exercise, even in small doses, can change the expression (activated vs non-activated) of your DNA. Research from Lund University in Sweden has described for the first time what happens on an epigenetic (i.e. non-genetic influenced) level in fat cells when we undertake physical activity.
This study showed exercise affects the genes that affect fat storage. Specifically this 6-month study included 23 slightly overweight people who hadn’t exercised regularly but now were asked to engage in physical activity.
The results of the study showed changes in around 7,000 of the 20-25,000 total genes of the subjects.
Read more at: http://scitechdaily.com/regular-exercise-induces-changes-in-dna/ or the full publication: Tina Rönn, et al., “A Six Months Exercise Intervention Influences the Genome-wide DNA Methylation Pattern in Human Adipose Tissue,” PLoS Genet. 2013 June; 9(6): e1003572; doi: 10.1371/journal.pgen.1003572