I have recently started working with a trainer and I am in the same shape as you describe. He said the headaches are likely from high cholesterol. I haven't researched this yet but will. I am a nurse and suspect it is high blood pressure, but it would make sense that high cholesterol is the cause of high blood pressure. If it doesn't improve in a week I would go to a pharmacy that has a blood pressure machine and check it before and after class.if it is high you may need medicine until it comes down.
Hi,
You said you were not been an active person apart from walking what you do.
The cause of headache in your case could be due to Hypoglycemia or related to Arterial hypertension.
I feel it is hypoglycemia as the body store of glucose comes after doing exercises and if you don’t have enough stores then it can cause various symptoms including headaches.
I think you should be meeting a physician and get yourself evaluated for Glucose intolerance and hypertension check.
Keep me informed if you have any queries.
Bye.