Jimmy was a very fat boy. He always used to be sad because of his obesity. So, he decided to consult a doctor. He said to the doctor, "How can I reduce my weight? Everybody teases me at the school."
The doctor advised him to exercise daily. After few days, he again went to the doctor and complained that despite of exercising, he couldn't reduce his weight rather, putting on weight.
The doctor asked him what exercise he was doing. Jimmy replied, "I go for horse riding everyday. The result is that I gained weight while the horse lost weight."
The doctor laughed and showed him how to exercise.