As you go fast you will use less arm & wrist and eventually mostly fingers. You could work on using just fingers at slower tempos, but it may be more efficient to use more wrist & arm. It might also be that bounce of the stick is quicker than your use to at 140, so the stick is back in your starting position faster than your use to. Once it's back you naturally want to play the next note, which will be rushed at 140.
This is all off the top of my head. For me, the tempo determines what hand & foot technique I use.