On the plane ride to Sarasota I was reading the USA Today and noticed a pretty interesting article in the sports section.  The article was titled, Foot Injury is Hard to Kick.  The basic premise was on the trend that is recurring in the professional sports right now surrounding plantar fasciitis.  The article focused on Albert Pujols but mentioned guys like Clayton Kershaw and Pau Gasol.
If you don’t know what plantar fasciitis is then read this article.
However, there was a line later in the article that really caught my attention.  “[Robert] Klapper says he thinks that sports specialization at a young age is leading to a lack of natural cross training and to a greater number of injuries caused by repetitive movements.”  THEN I listened to the Weightlifting Scoop podcast that featured Jared Flemming and in that podcast Jared mentions that he believes his success as a weightlifter can be largely attributed to his cross-training as a kid even while lifting 3x a week.
The point being made is here is the necessity to do lots of different activities and sports and do them often.  Kids are getting on traveling teams and playing year round baseball or basketball and its preventing their development of General Physical Preparedness.  Cross-training is absolutely critical for the development of ANY athlete and even more important for overall fitness of individuals.
I played every sport under the sun, excluding Cross Country, when I was a kid.  It helped create the basic athleticism, body awareness, and motor development that I rely so heavily on in the lifts.  Furthermore, I think it has helped keep me from more injury.
Bottomline: adults and kids alike who are looking to be in good shape, prevent injury, and potentially prepare for athletic excellence later must cross-train now.  Find a couple sports or activities that are fun and do them often.  The carryover is proven to take you farther in life and in sports than any amount of years of specialized work.