I have a playlist for my bike rides. I change it up every couple weeks to adjust to my shifts in musical taste/attitude. When I first started, I had the heaviest/most aggressive songs in my library on the workout list; artists like Five Finger Death Punch, Blood Stain Child, The Unguided and Trivium, along with the heaviest songs from Sevendust, Evergrey, and Amaranthe. I'm a "melodic" music fan, though. I love almost anything that has big anthemic melodies, solid beats/grooves, and that sort of thing. So gradually, my playlist has adapted from the aggressive workout list to stuff that keeps me going. Evergrey & Amaranthe proved to be great for my Biking, so Mercenary, Stratovarius and Symphony X have replaced all the aforementioned artists with The Unguided being the exception because they're pretty melodic as well. I just put my favorite groove based songs in a playlist on shuffle and ride for about 40 minutes to an hour and the music keeps me going.