Researchers have known for a long time that regular aerobic exercises like walking, jogging or cycling help to lower high blood pressure and also help to 
prevent strokes and heart attacks (Arq Bras Cardiol, 2016 May; 106(5): 422–433). However, there is data to show that a person can suffer a stroke or heart attack while lifting heavy weights because during heavy lifting, high blood pressure rises even higher. Many doctors recommend resistance exercises to help treat high blood pressure, but people with high blood pressure need to be very careful if they try to lift heavy weights. Instead, they should lift lighter weights with more repetitions and stop doing a lift if they feel pain.
A review of 14 studies of 253 people with high blood pressure, average age 60, found that lifting weights for eight weeks or longer lowered high blood pressure by the twentieth training session, and the blood pressure stayed lower for 14 weeks after the people stopped lifting weights (Scientific Reports, January 2023;13(1):201). Eight to ten weeks of strength training led to a reduction of 10 mmHg in systolic pressure and 4.8 mmHg in diastolic pressure, and was more effective in lowering high blood pressure in men younger than 50 compared to those older than 50. Strength training was most effective in lowering high blood pressure when people lifted more than 60 percent of the maximum weight that they could lift (one rep max), and they lifted at least twice a week for at least eight weeks.
High Bood pressure is common
High blood pressure is associated with smoking, drinking alcohol, obesity, an unhealthy diet, and a sedentary lifestyle. According to the Centers for Disease Control and Prevention (CDC), more than 116 million North American adults have high blood pressure, and fewer than 24 percent are able to get their blood pressures to a safer level below 140/90. Furthermore, 19 percent of adults have hypertension that cannot be brought to normal with any combination of medications (Hypertension, 2019;73(2):424–431).
How Can Lifting Weights Help to Lower Blood Pressure?
Exercising temporarily increases blood pressure and heart rate, widens blood vessels and increases blood flow. It increases blood flow by significantly widening blood vessels by relaxing the autonomic nervous system (Circ Res, 2017, Jan 20; 120(2): 249–251) and increasing production of nitric oxide that widens blood vessels. Nitric oxide remains elevated after exercising, and blood pressure is usually lower for a while after you finish exercising. This applies to both aerobic and resistance exercises. Any exercise strengthens heart muscles and blood vessels, so blood vessels can remain relaxed to continue at a lowered blood pressure (Curr Hypertens Rep, 2015;17(10):77)