MyDepressionList

I think exercising solely to get tired isn't the best motivation. It makes sense to exercise because you enjoy a particular type of physical activity, want to achieve some results, even if just for yourself, improve your health with a more active lifestyle, or simply bulk up/lose weight for the summer. If you have nothing else to do and you exhaust yourself just to escape reality for a while, you should ask yourself why you don't want to be in reality. And address that issue. Solve the problem, and you won't need to suppress the symptoms.
Although... I also escape reality, but through drawing. Apparently, I prefer to exhaust not my body, but my hand and eyes.