I was looking over my log book of my different races.  Even though every race is unique and a different course i noticed a pattern with my times.

If i'm running anything over 6 miles then my time is consistent.

Anything less than 6 miles and i'm consistent.

What i would like to do is get the times down.  Breakthrough the rut i'm in with them.  I just don't know how to go about doing that.

Is it speedwork that helps this?  Hill work?  Some of these races have hills and i typically train on mostly flat land, with the occassional rolling hill.

I just recently started speed work so i'm looking to improve that part of it.

I only run 1 race that is totally flat.

How can i effectively break through this time rut i'm in?

Thanks.