What are the main reasons why excess weight affects physical fitness? the heart has to pump harder. it is more difficult to exercise. the person sweats more. the person does not see results from the exercise. a heavy person gets more tired during exercise.

After looking at all the options available the main reasons why excess weight affects physical fitness are the following:  

The heart has to pump harder.
It is more difficult to exercise.
A heavy person gets more tired during exercise. 

All of this reasons come from the individual's excess weight. It sometimes gets to the point where the bones on the feet can’t take the weight.  

I hope it helps, Regards.