A theme which can be explored and expressed in a variety of different ways, existentialism is a belief based on the free will of the individual which suggests that all future development is created as a result of their own self determined actions.
People who do strengthening and toning exercises in an effort to trim fat from a certain area -- thighs, hips, stomach, or arms -- have the wrong idea. Although these exercises can help firm muscles, if the targeted area still carries an extra layer of fat, it won't look much different.
One of my favorite aspects of surfing is that it is one of the best avenues of cardiovascular exercise. And it leaves out the impact on your knees, hips, and back as something like running does. What other low-impact sport allows you to keep your heart rate up in the 65%-85% (or higher) target HR zone for hours on end with a huge grin on your face?