My dad is also hypertensive. In fact, he already had his first heart-attack. Thank God he was given another chance at life.
Nasabi na ata lahat rito e. Magpatingin sa doktor, uminom ng gamot na pang maintenance, kumain ng low-sodium diets, bawang, less stress, getting adequate sleep, etc.
Pero masasabi ko na makakatulong talaga ang regular exercise. And by this, I mean a balance of aerobic and anaerobic exercises. Diets and drugs just aren't enough when you already have a chronic disease like hypertension. You have to couple it with a healthy lifestyle.
You can encourage your dad to join a local sportsclub, like maybe badminton. My dad, since his first heart attack, has taken up table tennis and lawn tennis. Or take up jogging every once in a while with a friend. Ang kagandahan kasi ng nasa sports club nakaka-enganyo kasi marami kang kasama, plus you make new friends. So far, my dad is doing good. Of course he still takes his medication and cooks his own meals (so he has good control of the sodium and calories) importante pa rin yun.
It is also well to consult with a physician to get the all-clear before your dad can get into such activities. Start light, then you can pick up your pace from there.