If you are not an excersise freak, I would sugest you do walking, as you will not give up as easily. It is so easy to find excuses not to go for your run, but it is easier to walk to get the milk, or walk around the park or block and check out what is new. Walking can be a better long-term habit than running, and is easier on the body.

Don't get too involved with fads like 'fat burning zones', go with what you feel comfortable with, and that feels right for you.

Running is just way too hard on your joints. Swimming is the type of aerobic exercise that can work your entire body. Ever seen swimmers? They look about as fit as you can imagine.

Well the thing is everybody's body is different. The main thing is to excersize on a daily basis for 20-30 minutes. I do things with variety. Some days I swim, some I walk, some I do interval training (run and walk), some I play a sport. When our bodies get used to doing the same activity over and over it uses calories more effeciently therefore burning less calories. So do things you like, and change it up every few days. Work on both fat burning and cardio because they are both important and when starting out, don't overdue it, gradually build yourself up. Most of all HAVE FUN

Target heart rate is the key to calorie burning. If you look up any reputable personal trainer, they can help you calculate the target heart rate for your age and identify exactly how high your heart rate should be for how long to burn fat. You can even get this in an initial consultation with a personal trainer for under $100 and avoid a long term commitment or fees. As for the exercise, for fat burning it really does not matter as long as you get your heart rate into the right zone. You just won't realize muscle building or endurance benefits with lower impact (walking) vs. higher impact (running) exercise. Either one will make you a healthier person if done safely and regularly.

Running will burn more calories around 600 an hour. But walking will burn around 350 an hour and you are more likely to stick with it :)

Walking!
And Swimming is the best if you can swim!

Regardless of what some people think; the fat burning zone is there; however you need to realize why some believe it's doesn't exist. When your heart rate get's to a certain point, your body switches to a self preservation mode and stops burning "as much" fat as if you kept your body under that heart rate. Now, just because you are training really hard and keeping an elevated heart rate doesn't mean you won't burn fat and lose weight. It just simply means that your body will be increasing your body's potential to use oxygen in the muscles; building muscle and burning off the 200 carbs humans ingest everyday. The building of muscle and training of the body to use oxygen and burn off carbs will make your body a more effective fat burner and you will start to lose more weight at resting periods like sleeping, work, in the car, etc and you'll hit that fat burning zone when walking; riding a bike or playing a sport of your choice.

Having said all of that, you need to focus on your diet first, then your exercise to be at your maximum fat burning potential. Learn about negative calorie foods.

Well, you know there are as many advices on a subject as many problems you think of. There is no guarantee on taking any weight loss supplement or pill. There is no surety if you take a particular exercise and you would lose weight. Every human being is unique and so as their bodies. Just follow your instincts. When your hand is cut with a knife, no one knows how much pain you are going through. Similarly, you know what would be the best option for you to lose weight. For me, I know I have to walk at least 100 feet to keep my stomach in shape. For you it might be 1000 feet. Exercise should be done regularly; it is always recommended. Diet should be in control; the eating habits should be healthy and you should take balanced diet. Focus on your objectives, think of plans and work on them. I am sure you will be successful.

The absolute truth as I understand it is that exercise makes relatively little difference, compared to eating less. Exercise has benefits for your heart, and may serve as a distraction and an activity to replace eating. But there is no real effect on weight loss directly, once you move more than you do right now.