Train to shoot your .22 while breathing very hard

A friend of mine informs me of the standard dimensions for biathalon targets. They are:

• When standing, a circular 115 mm window in a white box allowing a black steel behind to be knocked down.
• When prone, a circular 45 mm hole in a 115 mm black insert in the above, allowing the steel behind to be knocked down for a hit in the 45 mm middle of the 115 mm black aiming point.

Since doing ridiculous levels of athleticism and still hitting anything is kind of cool, I figure I would like to know how I stack up against this at different distances, so this allows them to be printed at the official size as well as scaling to different distances.