Android : LocationManager dynamically adjust minTime/minDistance thresholds
AFAIK you need to call removeUpdates
and requestLocationUpdates
again.
Also, you can look into other ways to see if the phone is moving at all, like the accelerometer. Read about it here and see this other question's answers
But To give you more ideas, you need to present the problem itself. Don't try to optimize too early, until you don't have a problem. If you have you need to post details about it.