1, if your legs are thick because of obesity, then going to the gym for running is a very good way to lose weight. Losing fat as soon as possible can reduce the size of the legs.

2. If you are not fat, but your legs are thick because of living habits, work or natural reasons, you can only force your body to consume muscles through negative calorie metabolism, thus effectively reducing the dimension of your body. It is difficult to reduce the local roughness of muscle types. In other words, controlling the calorie intake in the diet forces the body to lose muscle. Running alone will not have a good effect.