The question is; what is the most efficient use of my time/volume to get there? Should I be focusing on running the majority of workout mileage at marathon pace to make current marathon pace (5:40/mile) feel more comfortable or should I be running more threshold and/or mile repeats at 5:17 and just work on slowly extending that pace? I'm assuming as long as total weekly volume is high enough, either method would produce results but I'm just wondering what everyone thinks would produce results faster..