I know I'll probably catch some flack for this, but I used to always listen the Bury Your Dead's album Cover Your Tracks. It's the perfect workout album, especially for doing cardio. It's heavy, but sort of mid-tempo. It sets a real nice pace for jogging. It's really corny, but there's a part in, I think the 5th track, where the vocalist yells "PICK IT UP!" And the song tempo kicks up about 20bpms and just sounds much heavier. It's quite motivating actually.