Agree with Tossucks. Pre-TOS, I would drink about 2 cups of espresso coffee and be a Diet Coke addict for the rest of the day. Overtime, I have lost interest in Diet Coke, for whatever reason, and maybe drink one every other day. I usually drink 1-1 1/2 cups of coffee in the AM (especially good with a marshmallow on top). NO reduction in muscle tension has been felt!
Some of us, including me, have breathing problems with TOS. There are a number of studies out there which state caffeine is a bronchodilator. It hasn't helped me breathe either.
The only thing it helps me do is start my day and everyone with TOS looks forward to a new day full of surprises

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Eat, drink and be merry -
Anne