PT (my son) is not a "sporty" type, so I have not felt compelled to provide lots of structured sports opportunities for him. If he seemed especially inclined and/or gifted with this bent, I might feel differently, but as it stands, any "competitive team sport" participation has been totally for the fun/social and exposure dimensions, as well as to reinforce our verbal assertion that being physically active is important. Basically, I haven't wanted him to be a total nerd. (We tell him that he can be a genius-type if he wants to, but that he can't be a "squishy man," so he has to train himself physically whether he is inclined to love doing so or not.)
Toward that end, here's what we've done...
He did local recreation league soccer for a few seasons when he was little. He took a year of "creative movement" when the girls were doing dance... this was the young boys' version of a class designed to encourage physical-movement-with-coordination-and-agility. He was kind of a spaz before that, since his body was growing faster than his balance could seem to keep up with. That class helped him get a handle on that klutzi-ness, plus it was just lots of fun. One year, I put him in a homeschool tennis class (taught by a good friend through the local recreation program). After that, he did swim team, which was good for him to cinch swimming skills and to push himself physically. He did a season of rec league baseball. For a while he did fencing (with his dad), just because he really wanted to and we found a cheap fencing club. This summer he did a nightly, week-long Upwards basketball camp. We currently have a semi-permanent badminton net set up in the back, which we use for occasional badminton and volleyball fun. We also keep a frisbee and a football handy out there.
So, that is to say, was have exposed him to a lot of these things in the cheapest way possible, just to make sure he's not a secret whiz at something and we don't know it, and to help him figure out what he might be inclined to enjoy enough to continue for life. (I figure that's sort of what goes on in public school PE once you hit middle school... a basketball unit, a soccer unit, a gymnastics unit, etc.) We also just want him to be able to handle the occasional adult scenario that might arise where a bunch of guys grab a basketball and start a pickup game, or grab a football out in a field at a picnic, or start up ultimate frisbee, or volleyball. These things come up, and we don't want him to make a fool of himself or be unable to participate from total lack of exposure to it.
For our official PE program for homeschool, my dad comes over and works their butts off three days a week for about an hour each time, doing "personal training" style workouts... calisthenics, running, weight training, isolated exercises, stretching, etc. They come in sweaty, red-faced, panting and about to faint. I figure that this is something important to work into habitual life, and is much more likely to be continued into adulthood than if your big exercise thing as a kid was soccer or football or something that required a team.
We didn't begin much of this stuff before the age that Z. is now. He, like PT, is going to be more intellectually-inclined than physically-inclined, I'd think, but that remains to be seen with his younger brother. I'd think that a "tad-of-cheap-exposure-here-and-there" approach would be beneficial for both of them. By the same token, their dad is a runner, and you have a built-in, easy thing right there if L. is willing to begin to "train" them in that. If it were my house, starting today I'd have L. (if he's willing) get all decked out and dressed for running like he usually does, and then take the boys with him for their running time (before his). They can walk fast for a minute, jog for a minute, etc. for however many cycles they can handle. If it is only five or ten minutes long, that's great. Make it a positive experience (no severe pushing, no impatient grumping, etc.) and a consistent time with dad, and they'll come to enjoy it. And if he heads out for his full run after this run with the boys, positively spinning that as they get older and stronger they can join him for that, they'll have a "goal" to look forward to.
Then figure out some cheap, quick-season sports option that seems to mildly appeal to Z. and let him do a season of it. Or you could just get deliberate about L.'s going out once or twice a week with him (schedule it) and "playing catch" or doing "dribbling drills" or whatever, just getting his hands and feet on various types of sport balls to improve his eye-hand coordination and ability to catch/throw, etc.
Anyway, there are lots of options, and I wouldn't feel extreme pressure at all. The only thing you're trying to avoid is the "pale, squishy man" syndrome when he's an adult.
Some thoughts from better experts than I:
I Timothy 4:7-8 "...train yourself to be godly. For physical training is of some value, but godliness has value for all things, holding promise for both the present life and the life to come." Read it with an emphasis on IS, to remind yourself that there is need and value in physical training. Then read it with an emphasis on SOME, to remind yourself that it isn't, however, paramount, even for little boys and young men. And finally, note that it never says that it is valuable to sit around on your butt spending inordinate hours watching others who have trained themselves physically, while you yourself have not! (Yes, current Olympic madness notwithstanding.)
Susan Wise Bauer, in The Well-Trained Mind: "If your teenager has a good chance of becoming a professional basketball or football player, home schooling proably isn't a good option. There's simply no foolproof way to plug a home-schooled student into the pro-sports assembly line that starts in high school...
"But players who are serious contenders for a professional team sports career make up a very small segment of the total high-school population. For the average, academically-inclined teenager, we think the question of organized team sports has gotten too much emphasis. How many students will find that team sports make up an important part of life after high school? And even in a regular school, very few players are actually able to play regularly on official teams...
"A more relaxed approach to physical education is simply making sure that your children exercise every day, from kindergarten through twelfth grade... (concentrate) on general physical fitness and on sports skills that (can) be honed either individually or without a large team of people: running, cycling, horseback riding, tennis, golf, handball, swimming. All are suitable for individual recreation as well as for competition, if the student enjoys the challenge" - from Bauer, Susan Wise, The Well-Trained Mind (New York: W. W. Norton & Company, 2004) 671-673.
She goes on, and the chapter is a good one. I refer you to the book itself if you'd like to read more. I tend to agree with her that most of the population is not going to be sporty enough to really excel in team sports. If PT (my son) seemed potentially to be one of them, we might handle it differently, but since neither his physical nor preferential bent is in that direction, we've not sweated it. I think it is safe to assume, at this point, that Z.'s bent is similar, and go with a similar "casual exposure" program regarding sports skills themselves, and a "committed to raising a non-squishy man" program regarding regular physical activity.
I know that those who have played on organized sports teams in institutional school (or even those of you who have seen and loved "Facing the Giants") will argue that there is still great value in playing team sports even for the child who doesn't have career potential with it. Granted. But for the purposes of discussion here, we're talking about the intellectually-inclined child who is not particularly naturally sporty. Does one need to feel obligation to provide him (or her, for that matter) with exposure to numerous team sport experiences?
Let us know what you think...