I can only speak from my personal experience and pass along my opinion on the excellent points made so far. I agree with just about everything said up to now.

I definitely agree that an exercise regime you do not enjoy is a regime you probably won't stick to. I love to hike and enjoy walking more than any other exercise. That's why I do it. If I had to get my exercise in a gym, I'd hate it and never get any.

Walking is a low impact exercise. This makes it very easy to start and very hard to overdo. It also means that in order to get the real benefits of walking you should do it every day -- or as close to every day as you can get. It takes longer to see results from walking, but those results tend to be every bit as effective over time as high impact exercise, but with fewer injuries.

I also agree strongly with wandering daisy that a good diet and avoiding overeating are absolutely essential to achieving an optimal weight and fitness. Habits are extremely powerful. Breaking bad habits takes effort and commitment. Because eating is so big a part of life, eating habits are especially deeply ingrained and difficult to change. The good news is that once you acquire good habits that same powerful force is operating for you, not against you. It is an accomplishment that can last a lifetime.

Good luck!