WHAT do you reckon is one of the main reasons most kids quit sport? While you're pondering, let's absorb this stat from the US: Each year 20 million children register for baseball, soccer, football, hockey and other competitive sports; about 70 per cent of those will quit by age 13.

Also according to the National Alliance for Sports, these kids will never play those sports again. Never.

Pass another doughnut and plonk them down at the computer screen until it's time to take them to hospital in a specially built and reinforced obese person's ambulance. Never is an awfully long time.

While you are standing on the sidelines of the cricket/netball/hockey/rowing this morning before you drive off to another sideline on the other side of town, do you think your child will be among the 30 per cent who stick at it?

Well, going by research, if you are a yeller, probably not. Children hate mothers and fathers behaving aggressively on the sideline of junior sports events, especially their own.

So, how's that new barracking rule working for you? You know the one where some sporting codes have introduced lollipops for parents to put in their mouths because their barracking became so out of hand and abusive.

I met a man in the butcher's shop (where all good gossip happens) and he's talking about his latest efforts coaching junior teams for his three kids - rugby, league and hockey. This is an intelligent, skilled, thoughtful junior coach out there in the nice suburbs of Brisbane.

"Every weekend I am called a f---wit and even a c---, on the sideline, in a carpark full of Mercedes and BMWs. Even in front of their kids."

Parents. We're just fantastic creatures, aren't we? We tell our kids how much we do for them, driving them everywhere for sport, buy all the gear so they look like mini-professionals - 10-year-olds in $300 boots and top-line $150 compression gear "to reduce lactic acid and muscular fatigue" - and what's it all about really?

If we're honest, it's ego. Not the kids'. The parents' ego. Deep down, if we interrogate our motives, what starts off as wanting our children to be active and learn to love physical activity can sometimes morph into something else.

What's all that hoopla about sons in the first XI and first XV stuff? Yes, it's admirable to strive to sporting excellence. But when I first moved to Brisbane and realised actual grown-up men were standing around at a party talking and obsessing over that kind of thing, I had to check: "You are talking about your KIDS' sport, aren't you?"

When I was growing up, parents mostly didn't really hang around. They dropped you and went off to take care of the other 10 kids in the family. Or did other grown-up things like earn a living, shop for groceries or go to the pub.

Mostly we played sport unwatched. The ref wasn't screamed at and abused by hostile parents. We played our sport for ourselves - basically for the fun of running around a paddock with our mates. And it was bloody fantastic and enormously freeing.

Someone who has spent his life playing and coaching sport and pondering how to retain young athletes in sport for life is Peter Gahan, head of player and coach development with Australia Baseball, after years at Queensland Academy of Sport. I rang him to pick his brains about kids and sport (in a month of Bernard Tomic's father assault charges and Nudgee College's steroid scandal) and to ask: "Where has all the fun gone?"

Fun needs to be at the very heart of sport, says Gahan. Even at the elite level, he says, research now shows all athletes need a fun activity in their training session. He says countries must walk the fine line of wanting elite sportspeople while encouraging mass participation.

"Research looking at 8000 schoolchildren in the UK revealed that the perceived lack of competency and ability stopped them from playing. They wanted to impress and look good but they couldn't, they gave up," Gahan says.

He says New Zealand has introduced a fundamental movement skills program in primary school with a sports officer in those schools to oversee the program.

"It covers 14 basic skills including running, hopping, throwing - the basics that are age-specific from Year 1. From what I hear, New Zealand is going to start kicking our arse at the next Olympics because, with this program, they will have a greater pool of athletes to choose from coming through."

He sees the obesity epidemic as entirely avoidable.

"A lot of the research on childhood obesity points at the fact that the kids are eating the same amount of calories as their fitter counterparts. They are just not moving. They are sitting in front of a TV or computer."

So, why do most kids quit sport? Well, one of the main reasons, apart from the obvious ones - didn't like the coach, not enough time, too much pressure - is one parents don't want to think about: The car ride home.

The car ride home after playing sport can be a game-changer. Whether you are five or 16, the journey from ground to home can be a non-stop parent teaching moment.

Whether you've played well or lousy, your dad can let you know what you should have done.

Should have run when you should have passed, should have kicked.

He becomes one of those shoulda- coulda-woulda dads.

Mum goes off about the netball umpire, bitch, and your coach not giving you enough playing time, cow. Yep, that car ride home can be pure joy.

If you can, try not to stuff up the car ride home, Gahan says.

The car ride home is when the kid just wants to quietly let the game sink in - whether a win or a loss.

They know if they've played well or badly. You don't need to tell them. The car's a pretty intense closed environment. They can sense your every thought, disappointment, anger, even a bit too much pride. It's all there, crowding in. Every sigh, every shrug is amplified.

So, I ask, what do you say on the car ride home?

Gahan says: "What about, 'geez, I love watching you play out there'?"

Email Kathleen Noonan