After a long day I decided to do a hard effort for 35 minutes on the bike trainer then follow it with a 2 mile run. Trainer sessions are boring but a good show or music can make it a tad bit more enjoyable. Benefits of trainer sessions is it will discipline you to not stop pedalling but instead to change gears as needed. Trainer sessions also allow for uninterrupted cycling, not having stop at red lights or in traffic. Following up a trainer session with a run is quicker and easier than trying to go out for a ride then come back and go back out in a decent time.