Dr.is runnig the best exercise for reducing weight?

One of the best: Running burns more calories per unit time than almost any other form of exercise. It is an excellent habit for good health, and a very effective way to lose weight. Don't forget to eat healthily and weight train, as more muscle will help you to burn extra calories all day long. Hope this helps!

Exercise by: itself has not been shown to be very good at all for losing weight. In Olympic runners, they lose only 600 cal/ hr of very heavy exercise. Added to calorie restriction, yes it is good. BUT, mixed exercise would be advised because with weight loss, unless you do weight lifting or similar, predominantly muscle mass is lost instead of fat.