I am a freshly diagnosed apnea person. My sleep study showed over 110 apnea episodes per hour over 15 seconds on average during a eight hour sleep study.. (max was 150 episodes/hr) I am told that is pretty high.
I spoke to my uncle who is a neurologist and been a doctor in sweden for years and he did some extensive checking for me and I learned something interesting that I wanted to pass on regarding the weight / work out correlation to apnea.
Here is the quick and dirty...
If you work out and intentionally or unintentionally increase your neck mass from the process (as I did, neck went to 21 inches) you actually make your apnea WORSE, MUCH WORSE !! not better. The added mass, though muscle, can further restrict the airway when you try to sleep.
I also read that sleep apnea was a factor in the death of football player Reggie White, here is one of many articles about it
http://www.kevinmd.com/blog/2004/12/reggie-white-sleep-apnea-and-cardiac.html
===> my case..
In my case, I was in the military during desert storm, I was a buff 5' 11" 210lbs, 21" biceps, 20.5" neck, 52" chest.. but I had a harder and harder time keeping off weight and getting a good night's sleep. The apnea went undiagnosed by the VA doctors, and at the time, without the current internet resources, i had never heard of apnea and thought that my gasping in my sleep was just due to enlarged tonsils.
So it got to a point where if I wasnt high on coffee or totally engaged in something WHAM i was asleep regardless of where, when, or what position I was in, including sitting straight up. So the end result, I put on a ton of weight over the past 13 years, mostly due to not having any energy and being totally exhausted all the time. (And my food intake actually decreased dramatically during this period).
LUCKY for me, i went on a road trip with some relatives and feel asleep in the mini-van, i had the typical apnea episodes during the 1.5 hour drive and my cousin the nurse gave me the 3rd degree about getting a sleep study and checking out this thing they call sleep apnea. I am glad the word is finally getting out to people about this.
I just hope the bi-pap treatment gets me some decent sleep :)
any weight loss from the increased energy and activities derived from that ... BONUS. well keep you posted.

