Training is a playmode for Re-Volt. Not much is known about it, only that it appears in some demonstration versions of the game at the "Game Mode" menu. Also, there're some pictures from Re-Volt Gallery which mentions the Training mode (lib11a.bmp and lib11b.bmp). The playmode was part of the game around the beginning of 1999, but was removed from the full version for some unknown reason.
At October 29 2013, the user Ripax77 published his discovery on the topic Playing in the Rolling Demo at Re-Volt Live, where he managed to acces the Training mode using Cheat Engine 6.2, and also the whole options of Rolling Demo. The playmode continues unplayable, but now is possible to visualize how the Training menu should look like.