To transfer your activities from MapMyRun to Strava, you'll need to export individual activities from MapMyRun and upload them to Strava in groups of 25 from our upload page. Athletes who are not subscribed to Strava can upload in groups of 15.
Go to one of your activities on MapMyRun.
Click the ellipses on the right side of your activity page and then select Download as TCX.
Follow the instructions on the page to produce a GPX file, which will be downloaded to your downloads folder.
Repeat step 3 for all activities you'd like to export and upload to Strava.
Log in to your Strava account.
Click Upload from the top right of any page and then From File and browse to select the file(s) from the unzipped file.
Name your activities, and adjust the activity types as necessary.