system
Given the following post, respond as if you're commenting on Reddit:
human
[DC] Can Barry Allen (or any speedster) run any speed between their top, “regular human” speed and their speedster speed?

For example, lets say Barry wanted to be an Olympic sprinter. Can he run the speed required without standing out? Or does any speed over his fastest, human speed generate lightening, and give away that he’s the Flash?
gpt
Yes. They can control their speed.   This would be evident when interacting with certain real-world items like say spinning a turbine.  If he went top speed, he'd destroy it, but he can limit his speed to go fast enough to make the turbine do what it needs to without destroying it in the process.