What I found, and what was one of the most deeply satisfying experiences on the Camino for me, is that your body's circadian rhythms will begin to coincide with those of the earth. After a few days of the Camino routine, it will become plain old "natural" to wake up before the dawn (with or without the bag rustlers), and get out on the road so you can make time and distance before the sun gets high and oppressive. Then you'll eat a small meal, find a place to take a siesta (what else are you going to do in the midday heat?), and then walk some more in the afternoon as the earth starts to cool. Farmers have been living this way for eons- modern day peregrinos are relearning the practice.
Out in the manmade world we constantly mask the earth's rhythms with lights, alarm clocks, air conditioning, etc. On the Camino, you'll find your personal rhythms will synch with those of the earth and nature- I found it was a profound feeling to experience.
So, I wouldn't even bring the alarm...