I was a fat a$$ who smoked two packs of cigs a day and ate at Mcdonalds at least twice a day, sat on my rear at night drinking beer and watching TV. I could not walk up a flight of stairs without breaking a sweat and losing my breath. My doctor gave me a choice one year during my annual physical, (2008 I believe it was), lose weight and get in shape, or go on medication for diabetes, high blood pressure, high colesterol, etc Said once I started on this medication, I would be on it forever. I opted for the other route cause I was sick and tired of being fat and tired........I started by walking every day, slowly adding a bit of jogging as the weight came off, quit smoking and started eating healthier. I lost almost 80 lbs, been smoke free for 7 years now and run at least 2.5 miles 4-5 times a week. I run 5k races once or twice a month. Just turned 51 last December, probably in the best cardio shape of my life. Still struggle with weight....manage to maintain with +/- 5-7 lbs, but man, it's like it takes me a month to lose 5 lbs and a weekend to gain it back....
Sometimes though, it's genetics. If high blood pressure runs in your family, maybe not much you can do about it.