my dad died for smoking very painful dead, and i quited 17 years ago and start to develop healthy habits, ive been running for 10 years, i ve lost a lot of weight 20 pounds at least, i use my bike to go to work all days close to 6 miles and run every time i can in my days off 3 miles. but i remember i started walking fast for 2 weeks an then start to run for 1/4 mile, and progressively i went to, 1-2 and later 3-4-5-6 miles in a year , the pain in your legs will be heavy for 2 weeks but later will disappear, it is easy built muscles in a gym than get your hearth right a running…and since your hearth is going right your whole live go right as well !! is hard every time i do it running is not easy even if you have do it for years, but every time i finished i know from my hearth to the last cell in my body will be better !!