Based on what I've seen in the console commands, there should be a way to increase movement speed without needing a trainer. I believe it was something along the lines of player.setspeedmult <#>
But I'm not 100% on that.
The console code to increase the players speed when moving is
Setgs fmoverunmult ##
Just enter a number where the ## is ( Default is 4 )*
* The number does not have to be a whole - If you want to you can use part numbers ( I tend to use 6.5 )
In using cheat codes that are typed into the console it DOES disable the Steam Achievements