There are many Android alarm clock apps but I couldn't find one that started a video file when the alarm is triggered.
This app is an add-on app to alarm applications (like Alarm Clock Plus) that can launch an application when the alarm rings.
Once you have an alarm application and you install this app do the following:
Just select the app 'WakeUp alarm add on' from your alarm application.
Select the video/music file on your mobile that you want to play when the alarm rings.
The next time the alarm rings it will fire your video.
How about have a video clip of push-ups or Rocky's training video to get you kick started out from bed?