Previously I was doing a HM plan that a local running shop gives out, the target race was the Dallas PCS HM, which I DNS due to flu. The week up to the race I felt pretty good, and was hoping for a PR.

This plan had very little speedwork, and no targets for the speedwork. Most of the speedwork was fartlek here and there.

At the reccomendation of other runners I downloaded "Run Faster" on the Kindle. I like the book and I like the approach. I decided to just jump into the Level 2 HM plan, as the milage seemed reasonable coming off 35-40 mpw.

For those that are not familiar with Run Faster, the author is a huge fan of hill sprints (3-10 x 8 sec flat out sprints) and progressive runs (speed up at the end of your LR). This plan has me cutting my teeth on the hill sprints-I am only doing 3-4 twice a week at this time.

In addition to this, my ortho has me doing light weights 2x a week in the gym/high reps on legs to help stabilize some issues I have going on in my left leg. He has also told me to take a couple of my easy 'filler' runs indoors to the treadmill, get on, leave flat, set pace and go.

Anyway-so this is the first time I have done any formal speedwork. And granted, I am just cutting my teeth on it at this point, no intervals...but my runs over the past week have been faster and what I would call an easier effort. It is not hugely significant, but my runs have went from the upper third of McMillan paces to the lower of the paces when using my last HM time. I feel better, am doing harder workouts, but I don't seem as gassed and recovery seems easier.

Is this what speedwork does?

That's the way the overall program is supposed to work -- cumulative, consistent mileage; hill sprints to work on strength and efficiency, speedwork to get  the feel of running a faster pace and improve thresholds between aerobic/anaerobic and steady state/lactate buildup.  And rest/recovery to allow your body to absorb and adapt it all.

   
Keep at it, you've got a good training cycle going.