thanks for the query.
this would be absolutely because of hypoglycemia
it would have been better if you have mentioned your age and work.
most of the people with low levels of glucose
would like to stretch muscles for lysis of glycogen
are you built thin?
your giddiness is due to decrease oxygen
to the brain .
i think u should go for blood sugar levels to rule out my cause of u r symptoms if not consult u r physician.