It’s well established that performing both cardio- and resistance training in the same session is decidedly better than doing them separately, but does the order matter?
A study involving men aged 18-40, who performed either supervised cardio- immediately followed by strength training, or vice versa, for 24 weeks (2-3 combined cardio- and resistance sessions per week), has found that over the 6 months, the order didn’t matter. However, the group starting with cardio did show slower recovery in the beginning.
http://www.eurekalert.org/pub_releases/2014-03/aof-pca031314.php