What's the origin of the term "jock" to refer to athletes?

The title says it all. As I understand it, Jock is a traditional Scottish name. How did it come to mean an athlete, or in some cases, a clique of athletes, as in high schools?

Because male athletes wear an athletic supporter, or “jockstrap” to support their package and keep the dangly parts from, er, dangling. The name jockstrap itself derives from the Scottish nickname for John. The word jock is also an archaic slang term for penis.

Cite: http://en.wikipedia.org/ wiki/Jockstrap#Etymology

Link deliberately broken as the accompanying pic might be considered NSFW.

If you’ll read the Wikipedia article carefully, you’ll see that it says that the term “jockstrap” derived from “jockey,” since they were originally designed for jockeys to wear. It’s possible that the popularity of the term was influenced by the term “jock” having been used to mean “penis,” but that’s not clear.

Hence also jockey shorts, which provide more support than boxer shorts.

But Jockey is a company name, and you can buy Jockey boxer shorts.

However, the name “jockey” for this style of briefs originated not with the Jockey company, but with Cooper’s.

Link broken since it is marginally NSFW:

http:// Briefs - Wikipedia

Bolding mine.

You’re right, the word jockstrap does derive from the word “jockey,” rather than from the Scottish nickname. However, they were first made for bicycle riders, or “bike jockeys,” instead of for equine riders. From the same Wikipedia article: