Thanks for posting your query.
Pain in right side of the chest you have after excercising after a long time seems to be due to muscular strain.
I advice you to stop heavy excercise for few days.
You can take anti inflammatory drug like Motrin
1 tablet with food as and when required (upto 4 tablets daily) for pain and muscle relaxant
to relif the spasm after discussing with your doctor.
Wishing you good health
Dr Saurabh Gupta