Well . . .
Shooting at ISO 3200 doesn't necessarily mean that the image is going to be really noisy. It all depends on how much light there is. If there is enough light, the image quality will be like shooting ISO 1600 in bad light. It's all dependent on light.
And in most cases, I'd rather get an alright shot at ISO 3200 vs. not getting the shot at all.
If you do shoot at ISO 3200 and manage to freeze the motion and get some shots, even if they are a bit noisy, you can look into noise reduction software like Noise Ninja [
Noise Ninja: The gold standard for image noise reduction ] to reduce the noise in an image after the fact.
Then again, if you take the approach I outlined in the other thread, who knows, you might get lucky and be able to pull the ISO down 1/3 or 2/3 of a stop towards ISO 1600.
The other options is to try to shoot with flash, maybe at ISO 1600 as a starting point, to get more light to help the sensor get a cleaner image. That might slow you down a bit, so you might have to be more selective of what shots you go after, and this will use up your battery faster.
Do you have more than one battery?
After this event, you'll have an idea if you want to upgrade to a camera that does higher ISO, or . . . start saving your pennies for faster lenses, such as a Sigma 70-200 f2.8 or something.
Me, right now, I upgraded from the Nikon D70s (which only went to ISO 1600) which I used my Tamron 28-105 f2.8 lens to a Nikon D5100 (which goes to ISO 6400 and can be pushed to ISO 12,800 or 25,600 -- although that is noisy) which I currently only have the Tamron 28-75mm f2.8 lens and Nikon AF-S 18,135mm f3.5-5.6 lens right now. I want the Sigma 70-200 f2.8, but waiting to see if my daughter decides to do cheerleading or gymnastics next year. If she does gymnastics, I want the Sigma 70-200 f2.8. If she decides to do cheerleading, I might consider getting an older Nikon D90 to use my old Tamron 28-105 f2.8 lens on, or maybe start looking at the Nikon 24-120mm f4 VR II lens. But that's some cash.
In the short term, I'm just cranking up the ISO on my Nikon D5100 and "faking it" by trying to clean up the noise after the fact. I'm getting lucky with cheerleading so far and managing to shoot at near ISO 3200 vs. having to crank it up to ISO 6400. But I'm waiting for my daughter's gymnastics competitions to start. Usually the lighting there is pretty brutal.