That's a really silly stereotype. Oh well, some people will always be ignorant. One afternoon at your local park will find dozens of people jogging with their dogs.

I'm a huge cat lover. And, I'm not the "little old lady with cats" nor am I overweight. In fact, fitness is my favorite pastime. This cat lover could run circles around your friend and I'll bet $50 my BMI is much lower- unless he or she is prepubescent.