triathlons do not allow music. you cannot race with music - therefore you cannot train with music. you cannot do anything during training that you cannot do during the race.
training in silence - you hear the sounds of your feet on the pavement, the changing of the gears on the bike, the crunch of leaves under your feet, the sound of your breathing; not only do you feel your heart pounding, but you hear it.
painful at first - the focus is not on the music to motivate your energy anymore, the focus is on you. your energy, your motivation, your momentum, your drive. initially, that transition is almost paralyzing - you cannot imagine how you will possible get through the run or ride - but you do. and it is amazingly inspiring. mental focus, and mental non-focus. your mind can go anywhere or no where. it is up to you, nothing to distract you, it provides an amazing sense of inner peace.
today - 2o mile ride, 1 hour 2o minutes of powerful silence