A while ago I explained that I'm a 16 flat 5ker who I feel has just about reached the limits of taking advantage of my raw speed. I can do mile repeats with nearly the same effort as I do 400s at the same pace...
Suggestions to get faster were more strides and 10x30second hills with full recovery (2minute rest in between each 30seconds on)
Been doing these exercises and drills often and I think they have actually been working... my 400 and even 200s seemed to be getting slightly faster and a bit easier
Any other suggestions to mix it up again and continue to work on raw speed?