With this script you can download all your activities from www.runtastic.com in .gpx format. Runtastic restricted these exports to 5 per hour. That's why I adapted a little bit christianewald's script.
❗ Only tested in Google Chrome 41.0+
Login to your runtastic account and go to the page where all your activities are listed.
Then open the developer tools of Chrome with CMD + OPTION + I
and go to the console tab. Now copy and paste the following script in the console line and press enter. The usually content should disapear and the downloads should start.