Olpe 11. If you walk and play fairly quickly, golf provides real exercise—not aerobic exercise, usually, but a mildly elevated level of metabolic activity. Golf doesn’t ruin your knees the way running and tennis do, and the time you spend playing golf is time you can’t also spend sitting in front of the TV eating coffee ice cream and drinking Yoo-hoo. Mark Twain famously dismissed golf as “a good walk spoiled,” but it’s actually a walk improved, since golf, unlike mere walking, gives you something challenging to think about, as well as something interesting to do with your hands. Golf is a walk with a purpose.