Welcome to HCM
Headache after work out may occur due to a lot of reasons and most common reason is Hypoglycemia
or decreased glucose
in blood so taking glucose just before exercise will help. You can take bananas, biscuits etc.
Other possible reason may be Dehydration
One other reason is exercise cause vasodilatation or increased blood flow so over all pressure in brain increases and this may cause headache. Though your blood pressure in higher normal range as per your age but most probably while exercise its going to higher levels.
You can take Aspirin
for this but there are many side effects of aspirin on chronic basis as gastritis
or development of ulcers in stomach. So as per my opinion kindly visit a doctor and take advise for High BP and once your BP will be in normal range you will see improvement.
Hope I cleared your doubt.