You may consider me to be sprinting in a circle
Or helping you to navigate the alphabet
I might even be like a small explosion.
But you'll have to prove that you know me regardless.
What am I?
Hint #1:
Sprinting could be by itself, the circle might be on the subject of something instead and it would still fit.
Hint #2:
You don't have to navigate the alphabet very far.
Hint #3:
It's more about the sound, really.
Hint #4:
Think about another term for "proving that you have knowledge of something".
Hint #5:
Consider that my favourite way of creating a puzzle is to use synonyms of things that relate to the subject indirectly: for example, for "leaves" I might say "If you want to be green, move away from the room." Think about synonyms for words I've used in each line, especially line 1.
Hint #6:
Lines 1 and 3 refer to colloquial names for the object, rather than the object itself. Line 2 is about an idiom that describes what the object does. Line 4 refers to something you need to do in order to use one.