Meh, the summary doesn't bring up any of the new stuff.
We *know* that exercise has an effect on the body. We *know* that exercising increases concentrations of growth hormones, anti-inflammatory responses, and metabolic rate adjusting factors. We *know* these adjustments are made through methylation patterns over enhancers/promoters.
Furthermore, there is no *change* in the DNA. Any alterations that occur do so on the back-chain of the DNA, which is normal behavior as the backchain is modified by ALOT of different factors. No nucleotides are being mutated or swapped by exercising (unless you imbibe strange and unhealthy body building substances).
Last, the adjustments made to the exercised cells are in *response* to the exercise rather than proactive as the summary suggests. It would after all be really freaky if your body started building up muscles *before* you started working out. That would actually freak me the hell out.