First, at its best, sports builds community. Different teams attract different mindsets and personalities. Participation in two disciplines is the seedbed for friendships that blossom from a common experience. Because tennis was my first love, I played with my high school team in the fall and ran track in the spring. As a distance runner, I became close to a number of girls who also ran cross country. I still remember that part of me wished that girls' tennis was in the spring so I could have run XC. I remember telling my track teammates/friends that I thought they participated in the tougher fall sport. They didn't disagree. And today, I coach cross country. I tell my own runners upright: I did not run XC... but I certainly came to know and revere many young women who did.
Second, cross training provides tremendous physical and mental health benefits. Some skills from one sport transfer well to the another. In some cases, participation in one sport may actually enhance the other. For example, during his junior year in St. Ignatius, JV basketball and volleyball coach Kareem Guilbeaux, played on the boys volleyball team for the first time. When the volleyball season ended and he returned to summer league basketball he realized something new. Whereas he once merely rolled the ball in at the rim, he could now easily dunk. Volleyball taught him how to use his body to properly jump. We call those "hops," volleyball players know it's fundamental to the game.
Third, every sport provides us with its set of challenges and we confront our limitations. The lessons we learn on the field transfer to those off the field. John Paul II said it himself: Sports are the true school of human virtue.
Ultimately, those who can play two sports simply should because they can. If one is endowed with the talent and ability to participate in more than one sport, give thanks! Do so! The fact that we live in a place where we have options and the freedom to choose is also a gift. Many people in the world long to play, and many cannot for a host of reasons—physical limitations, a lack of resources, etc. Others lived in an era when sports were limited by gender and race. This is not the world most of my student athletes are growing up in—and thanks be to God for that!