The idea is heavily borrowed from Washington, DC's street naming scheme (which is totally awesome, and uses alphabetical items and number of syllables and single letters to let you know where you are in the city), Google's Android naming scheme (alphabetical), etc...
Pick a category of thing. For the purposes of clarity here I'll pick animals. We then go in alphabetical order coming up with animal names. First we go through single syllable names, then double. then triple (obviously you may never make it having switched to another object type or another system, but this is the concept). If you can't think of a matching animal for those conditions, skip to the next letter and try again.
And the size of the object identifies the scale of the sprint. A minor sprint is identified by (in this case) an animal that can be comfortably carried by a human. A major sprint is identified by an animal that cannot be comfortably carried by a human.
So, using that logic and an animal as the category, you could have:
- Ant (minor sprint)
- Boar (major sprint)
- Cat (minor sprint)
- Deer (major sprint)