Relaxing. Not classic, not rock, not rap. Upbeat gets the adrenaline going the smooth music that gets you lost in the music helps to
Has to be motivational. Not Adele or Taylor Swift or Bruno Mars.
Can't make your ears bleed, so no Justin Bieber.
Something along the terms of Eye of the Tiger or Beat it my Michael Jackson. Classical is good too. Primordium, Mozart, Beethoven, etc
Yeah It has to push you to do something
I think I heard somewhere that listening to pop and rock make you unconciously run faster. The beat of the music should be consistent and fast enough to match your pace to.