Our heart pumps blood to the whole body therefore it is essential that we keep our heart healthy. It should work at its maximum capacity for at least 20-30 minutes every day. Do anything that totally exhausts you for 20 minutes. You can brisk walk, run or climb stairs instead of taking an elevator. Exhausting your heart for 20-30 minutes per day keeps your energy level high all day.
Join a gym or any other exercise program which you can follow regularly. Working out daily or at least 4 times a week not only keep you physically fit but also frees you of stress and tension.
If joining a gym or going to gym is not possible regularly, buy fitness equipments and exercise at home whenever you get time. Moderate exercise can be done anytime of the day. Treadmills or exercise bikes and many other types of equipment are quite effective in keeping you fit. Investing on fitness equipments is always better than to spend money on treatments later.
Make exercise your part of life, like using stairs instead of elevator or parking your car some distance away so that you need to walk to reach it (of course if you are not in a hurry ).
Yoga is a good way to remain fit physically as well as mentally, but it requires some degree of regularity and discipline to achieve maximum gains.