Underage in gymnastics -- what's the benefit?

Good point, wandel.

Smaller= Tighter tucks= faster= easier. If spinning or twisting; you make yourself as "small" as possible to increase speed. More importantly, I'd wager, is the uneven parallel bars. When you watch those kids get flying around on there; the bars are going to flex less if you weigh less... which makes things easier than just the straight weight/strength ratio would suggest. Notice that despite the fact that bicycle shocks are now widely available; serious cyclists would never use them. Why? Because when you're pumping hard the suspension robs you of some of your power that would otherwise be transferred to the drive wheel. I can only assume this same phenomena applies to the bars when the centrifugal force is pulling the bar further away from straight; it results in a net reduction of the slingshot effect.

I used to do gymnastics when I was younger (not any where near Olympic capacity), but definitely age has a huge factor physically. You are much more flexible at 9 than 16. And like other said the balancing thing, hips and boobs make your balance a bit different than some one who equal weight distribution throughout their body. Imagine balancing a something straight like a pencil and then imagine balancing something wear the weight is different throughout the length.

You see the gymnastics doing a flip on the balance beam - if you are about the same shape and even weight from head to toe it doesn't take as much work to keep the weight evenly distribution to stick the landing. Also, the balance beam is proportionately larger to some one smaller. Other things like the uneven bars - being smaller it is easier not to hit the bars or floor as you are swinging about.

And also as I heard - the fear factor. Remember being a little kid and doing all sorts of crazy stunts without thinking you could get hurt? You tend to be more cautious, for good reason, as you gain experience.

Thomas - those girls do have boobs - they wear athletic type bras to hold their boobs in as much as possible. Many when they are dressed in their every day clothes you can see the difference a bit more.

I don't see why age should come into play though - other than the safety issue of a child. Every athlete has an advantage or disadvantage depending on their size and shape. Will there be height limits for those that are unfairly tall in basketball?

I saw a comment by - I think it was - Nellie Kim, famous gymnast who is now head of some federation, who mentioned the fear factor in that the much younger girls had less of it.

linkat reminded me....when I was little I loved all the tumbling and floor exercises. Wasn't bad either. I mean, not great, but I had nothing to complain about. I was a skinny little kid.


Then we were introduced to the uneven parallel bars. To this day I can remember the "oh my god that feels gross and hurts" feeling when I jumped up and laid my hips across the bar where they were supposed to be (I wanted to lay either too high or too low on the bar) Those future womans hip bones were not going to stand for having to be pressed up on the bar supporting even my much smaller frame.

bleaccchhh...strange what you remember, huh?

Most gymnasts don't have much for boobs anyway because their body fat is very low. The one chick on the US team is the exception. She's got some big ones.

I suspect it has lots to do with being smaller, looser and less prone to injury.

Lots to reply to! Sorry for not responding to everyone individually, but let me run through some of the explanations people have offered.

Explanation 1: "Smaller is better because of the force-to-weight ratio"This argument applies to men as much as it applies to women. So why aren't we seeing more underage male gymnasts?

Explanation 2: "Gymnastics is a terribly tough sport, so women have to retire early."
I agree gymnastics is a tough sport, but again, it's tough for men and women. So why aren't more men retiring before they're 20?

Explanation 3: "Puberty changes the body's center of gravity, which messes with balance."

Weeelll ... that's more plausible, but not quite in the way it was stated.

As a physicist, I'm having a hard time seeing how this this can have a big effect. (Because I'm a physicist or although I'm a physicist? I don't know.) For one thing, the important thing for achieving balance is that you have a center of gravity to balance on. Every body of mass has that, and certainly puberty doesn't change that.

Another reason my physicist intuition is having a hard time with this is that the effects of a girl's puberty on her center of gravity offset each other a good deal. A human body's center of gravity is somewhere near the belly button. Puberty makes girls grow boobs above the belly button and hips grow below it. It's a few pounds in a 100 pound body, fairly close to the center of gravity,
button. The effect of puberty is to grow hips about 10 inches below the center of gravity and boobs 10 inches below it. So we're talking about a few pounds on a 100 pound body, fairly close to the center of gravity, distributed more or less symmetrically around it. Difficult to see this as a show-stopper effect on the center of gravity.

But this leads me to another explanation that might work.

Explanation 4a: "Puberty changes a girl's moment of inertia"

Whereas the effects of greater boobs and greater hips cancel each other out on the center of gravity, they add to each other where its moment of inertia is concerned. (For non-physicists: the moment of inertia is a body's resistance to changes in spin, much as mass is its resistance to changes in movement.) It's not dramatic -- again, a few pounds out of 100, fairly close to the center of gravit -- but it has some effect. I suspect, however, that the largest effect is ...

Explanation 4b: "Puberty messes with movements that are carefully coordinated, timed, and learned over 10 years."
To be a world class gymnast, you have to train your movements over a long period of time, until they become second nature. The changes in puberty, however unspectacular, create a misfit between a girl's instinctive movements and the physics of her new body.

I guess it's it is this mismatch, not the physics itself, that's the problem: the un-learning of 10 years of training. The frustration of not being able to do what came naturally just a year ago. The anxieties that come when you miss your bars or fall off your horse.

It would be interesting to see what women are capable of when they push through this period and into womanhood. I hear that gymnastics is part of college sports. Are there studies comparing the exercises college gymnasts could or couldn't do before puberty and after adapting to their new bodies?

If any of you knows of such studies, I'd appreciate a pointer.

What we see is short, lightweight male gymnasts, not necessarily under-aged male gymnasts. There aren't a lot of tall male gymnasts. It's all about strength to weight ratio . For men that ratio seems to peak during the early 20's.

Also, it's not just physics, it's physiology. Females are much more limber, supple and flexible at younger ages.

Here are the stats for the Chinese male team:
YANG Wei 1.60 /5'3" 54 /119 Feb 08 1980
LI Xiaopeng 1.62 /5'4" 56 /123 Jul 27 1981
HUANG Xu 1.62 /5'4" 59 /130 Feb 04 1979
ZOU Kai 1.50 /4'11" 47 /104 Feb 25 1988
XIAO Qin 1.63 /5'4" 52 /115 Jan 01 1985
CHEN Yibing 1.60 /5'3" 58 / 128 Dec 19 1984


and US team:
HORTON Jonathan 1.55/5'1" 57/126 Dec 31 1985
TAN Kai Wen 1.63/5'4" 64/141 Sep 24 1981
BHAVSAR Raj 1.60/5'3" 54/119 Sep 07 1980
HAGERTY Joey 1.63/5'4" 61/134 Apr 19 1982
ARTEMEV Alexander 1.68/5'6" 61/134 Aug 29 1985
SPRING Justin 1.70/5'7" 64/141 Mar 11 1984

Very good point. Thanks, InfraBlue, I stand corrected.

Men's gymnastics requires upper-body strength. Have you seen them support their body weight at arms' length?


Have you ever rapidly gained or lost a great deal of weight? I was forever crashing into walls, as I misjudged my trajectory.

Given the intricate moves required for world-class gymnastics, I can believe that changing the center of gravity even a little bit will throw off their whole routine.

And I don't think boobs and hips would necessarily cancel each other out and leave the center of gravity unchanged.

Well, as InfraBlue already pointed out, my premise on this point was false. Male gymnasts are very small after all, even though they're not underage.


True. As I mentioned two posts ago, I now think this change is the crucial point. Because, as you say, the movements are so intricate, it's hard and frustrating to un-learn what you've learned over 10 years, and re-learn it with a new body.

Some Olympic gymnasts, Tasha Schwikert for example, later participated in college gymnastics. I googled for interviews, studies, etc, to get an impression of what they can now do compared to what they could do as teenagers.

The early to do the early to learn the early to learn the early to do perfectly................

Thomas, woman being human, you should know that boobs and hips don't necessarily grow at the same speed or to matching dimensions.
Some women after puberty are all hips and ass, while others get luckier in the chestal region...

I once saw an interview with a guy who'd done his PHD in sports medicine. He had studied the athletic differences between top tri-athletes and toddlers. The doctor monitored both subjects playing for two hours. The athletes had to copy every movement the toddlers made. It just about killed these uber healthy guys. They couldn't keep up with the kids. Kids have more energy, plain and simple.

Plus, even a symmetrically endowed woman has a higher moment of inertia than a girl, which doesn't help with somersaults and things like this. That's what I didn't catch in my first look at the physics.

Congratulations to Virginia's Gabby Douglas for her awesome performance in the Olympics' gymnastics. Gymnastics, to me, is the perfect combination of strength, grace, balance, and creativity. I so hope she participates in the 2016 Olympics and hope that endorsement deals for her, and they will be coming in, will be fair in all ways. GABBY! GABBY! GABBY!

Yes she was terrific. Although being 16 - in four years she will be 20 - much harder to be that good at gymnatics after the teens, although not impossible.

With her incredible smile, I can only imagine she would be a perfect face for endorsements - funny that was exactly what I was thinking this morning. Her face is going to be everyone on endorsements.

We'll see. The reality is that fair skin and blond hair still attracts more endorsements that big smiles and Olympic gold. Just ask tennis players Sharapova and Williams.

Not being a huge tennis fan I don't know Sharpova - name is familar, but I see the Williams sisters every where. And they aren't anywhere near as cute as Gabby.

Sharapova is a successful tennis player who has won a career slam but has only a fraction of Serena's accomplishments and is not quite even with Venus. She is also the most marketable athlete in the world and crushes Williams in the endorsement department.

Funny that I am familar then with the williams sisters more so than that other tennis star...I guess the endorsements (at least for me) aren't helping them much.

When you mentioned Sharapova I just thought she was black as well as you were pointing out how african americans do not get as many endorsements- I didn't realize you were using a comparsion . Just goes to show what I know