To transfer your activities from MapMyRide to Strava, you'll need to export individual activities from MapMyRide and upload them to Strava from our upload page.
Go to one of your activities on MapMyRide.
Click the ellipses on the right side of your activity page and then select Download as TCX.
Follow the instructions on the page, which will produce a GPX file, and the file will be downloaded to your download folder.
Repeat step 3 for all activities you'd like to export and upload to Strava.
Log in to your account on Strava.
Click Upload from the top right of any page and then "From File" and browse to select the file(s) you downloaded. NOTE: files can be bulk uploaded to Strava in groups of up to 25.
Name your activities, and adjust the activity types as necessary.