Answer:
It helps you stay alive and more productive. I'd go with the other person but ill share my answer. If your laying in a bed scrolling through pictures of people. People that looks way ''better'' than you, you might feel sad. However, when your exercising the only focus is to exercise. Nothing else, while your exercising you'll feel good about the outcome and then you won't stay to gloomy.
I hope this doesn't offend anyone, my answer is not made to make people mad. My answer is only education purpose.
heres a banana :D