Thank you for your query.
When you ask what the maximum blood pressure can be I suspect you are asking when the reading is no longer normal. Any reading above 140/90 is per definition high blood pressure
. A persons top reading can rise up to 220, with a huge risk of suffering a stroke
. When exercising , you should exercise to 80% of your target heart rate
and then rest. At your age that is 122. Treating hypertension
without medication consists of keeping a normal body weight, cardio vascular exercise and reducing your salt intake. I trust you find this helpful.