You know exercise burns calories, improves your mood and can help your heart … but did you know it can actually change your genetic makeup? New research published in the journal Cell Metabolism shows that subtle shifts in D-N-A start taking place soon after we make the move from couch to treadmill.

Researchers from the Karolinska Institute in Stockholm put 14 relatively sedentary young men and women on an exercise bike and took a biopsy of muscle cells from their quadriceps before and after twenty minutes of exercise. They found that more genes were activated after exercise and that their D-N-A displayed less methylation. Methylation is a process in which chemicals called methyl groups clog the D-N-A and limit the cell’s ability to switch on certain genes. Methylation dictates whether a cell develops into an eye or a lung, for example, but it also primes muscles for more efficient work.

The more intense the sweat session, the more methyl action in muscles and the better the participants worked. They also found that caffeine mimicked the muscle morph, but your daily cup of joe is no excuse for a date with the gym. You would have to drink almost 50 cups of coffee a day, way too much for even the most avid java junkie, to get the same effect afforded by exercise.

The study discounts the previous belief that adult cells don’t change their D-N-A methylation. It just goes to show that if you don’t use it, you lose it — but you can certainly get it back by putting in a little sweat equity.

If you’ve fallen off the workout wagon, start slowly to get yourself back into shape, and be sure to check in with your doctor before starting a new regimen. Too much too soon can cause quick burnout.

It’s not too late to adapt your D-N-A for the better.