Many thanks for your comments Greg & Donald your advice is already helping especially 'hugging myself'
Greg excuse my being vague, I think you are spot on re having a stiff thoracic spine, my description would be that it is more of a discomfort around the T5 area than outright pain which occurs towards the evening and not during training. I train every morning 0630 alternating between resistance and cardio have never experienced this discomfort during training. The first time i noticed the discomfort was around a year ago strangely enough during an evening session of yoga. I have also noticed that the more I stretch the more pronounced the discomfort becomes.
As a note I have never being flexible as a person no matter how much I stretch.
Many thanks once again