Science Friday: exercise and DNA

A segment on Science Friday discussed the effect of exercise on DNA. The headline is a little misleading -- DNA itself is not changed; rather, DNA methylation changes. Says Dr. Juleen Zierath:

[W]e found that 35 minutes of high-intensity exercise was sufficient to have a removal of these methyl groups from the DNA and a production of proteins which would support the metabolism of sugar and fat after exercise. So it's not just to exercise. In this case, you needed to do an exercise bout which would be at the level of where you might not be able to comfortably talk if you're running with a running partner. It's not like walking. Running or biking at a level of exertion where it's hard to carry on a conversation for about 35 minutes.

I've been deliberately avoiding high-intensity running lately, but I'm about to introduce some interval training in the next week or two. I have nine weeks until my half marathon.