I lived under coaches that really felt strongly about speed work, in consistent and intense doses through the winter. I think they were missing a few points that both he research and the anecdotal evidence of those who have ended up running at elite levels suggest.
1. I see three components of middle distance speed work....pure power, neuro-coordination and reactivity, and speed endurance.
I agree that Pure Power (stimulated through weights and short hill running <25 seconds) should be addressed consistently, and works such different systems that it wont interfere with your basis general aerobic prep work. The nuance is that you have to act like a sprinter -- short, highly intense reps and alot of sitting around resting in between. I see coaches pushing the rest on hill work in the winter and I see injuries and mistimed peeks.
Neuro coordination is another element that you have to address and stimulate through the regime..plyos and drills are meant to focus on quickness, not power. "High Knee" drill over 40 meters what I would notice is toward March how much less my feet would "wobble" when they touched -- I would be in balance, my middle body would start to relax, and the turnover improved. It feels muscular but it isnt....
Speed endurance is the phase that I think the evidence points to saving until near competition. I just dont think you can work in anything near full effort intervals above 200m without expending energy that competes with your aerobic training, and possibly stimulate the enzymatic response that will bring you to mistimed peeks and mistimed stale periods during the competitive season. 3*3*200 at 800m pace is not an appropriate workout for January, unless you want to peek February 15th.
A separate point...
The Muscle hypertrophy response to resistence has a relatively fast response -- muscles are used to being used and torn down on a daily basis and rebuild over a 48 hour period. Other physical systems (blood flow, red blood cell density, capillary developement, mitochondrial density, energy transport systems) all take a longer time to hypertrophy....Thus the idea that you "feature" that training for 9 months of the year, and layer in the last two months of pure work specific to th event you are running...As a young athlete I was impatient, and I wanted to drill fast times in practice to give me more confidence and benchmark my progress...Coach "g" would scream at us "FOCUS" --particularly if we started to hammer an interval, and really hammer into us that you had to "LIVE LIKE A CLOCK" --ie worry about the CONSISTENCY of what we were doing rather than the QUALITY during the dark winter months. Teasing those trigger levels in your body -- AT, LT, -- changes your physiology invisibly and takes time and effort. All the research we do and study of great athletes I think is useful because it lets you adopt the philosophy and have faith in it even when you or your athletes dont feel like you are getting faster in the fall or winter and can't see how a 16 mile run could possibly influence an 800m sprint.
Again, apologies in advance for the rant....