I think Surfacing and Master-Classter are both correct.
Some perfume houses may have released fragrances designed specifically for use while doing sports or afterwards, but it's hard to say. These fragrances would have been relatively light and refreshing, having an effect almost like a traditional cologne. After all, no one wants to wear a heavy, serious frag while playing tennis or lifting weights.
But I believe in general that most of the Sport frags are intended for casual wear, whether doing sports or not. Many of them are flankers, or variations, of an existing fragrance. The Sport version, sometimes bearing little resemblance to the original, is almost always lighter, fresher, with very subtle base notes, and isn't particularly long lasting.
Many younger people prefer these type scents, so it is a way for a perfume house to take advantage of an already existing name and draw customers who may know the brand and name but may or may not necessarily like the original fragrance.