answer:Number 2 is most likely just a muscle cramp in the chest. No big deal (if I am right). For some reason I think it is more common in young people, but my memory is not for sure on that. Number 1 is a little odd. Do you have any sort of post nasal drip, runny nose type of thing daily? Or, wake up with a stuffy nose? That sort of thing is more likely to be a problem when sleeping flat on your back, and can slow your breathing. Also, laying on your back exacerbates sleep apnea, which would inhibit breathing, and could result in feeling heavy in your chest, but it being painful is what makes that a little odd. Is the pain the same in both circumstances? Also, do you lift a lot during the day?