BTW I posted this on another T&F board, I thought it was worth to share it here and ask for other people's view on the topic (800m training for sprinters moving up / predominant muscle fiber type being IIa).
Beforehand it is worth to mention that KitKat is a well known 400m coach who had great results in the past. And CF is Chalie Francis, who – PEDs or not – developed a great training system for the sprints and was a very scientifical mind. GPP = general preparation phase (base phase in middle distance), SPP = special preparation phase, SE1/SE2 = different types of speed endurance (sprints up to 350m, high intensity ones). Also that a session like 3x8x200m @ 36 seconds is for a trained long sprinter something like a recovery run.
Charlie Francis believed that you need a big aerobic base for increased capillarity and aerobic capabilities tissue. For this you do year round three times a week so called extensive tempo, this means 100m runs at under 70pct of your 100m PB, i.e. 3x10x100m with 30-60s walking rest. Total volume per session ranges from 1000m to 4000m. His main idea is that this way you will get the aerobic capacity (via capillarization and mithocondrial development) in your fast twitch without distroying them - or better said without hypertrophing your type Ia/b fibers, which you don't need /won't get recruited for fast running.
a) Commonalties of Interval Training and CFTS / KitKat
The main commonalty of the interval based programmes is Charlie's extensive tempo. In one of his posts he mentions that it’s also suitable for middle distance runners, an 800m guy should do about 4k of volume per session. This pretty much what is said about Gerschlers’ method (10x4x100m or 3x8x200m with jogged recoveries). Biggest difference is that obviously with CFTS you do sprint and weight training in the days between, for the 800m variant (and upwards) of Gerschler you do more and more extensive tempo, intensive tempo at specific pace and easier weights. Especialy after GPP you add more SE runs. But the pattern is similar in both.
I think KitKats 3x3x300 with 100m jog recovery (I guess anywhere between 50 and 90s recovery) or 200m runs also fit well within this pattern. Also Clyde Hart's 200m pyramide follows the progression scheme of the method detailed in Gordon Pirie's book.
b) the fast (or middle) twitch 2a dilemma
(( i am assuming a) that this is not relevant for a type 2B monster like nowadays elite sprinters and b) that we are born with a fix ammount of fiber percentage and that we can only work on hypertrophy of any type or increase the oxygenation))
The explicit idea of Lydiard/Daniels’ “long runs” (over 12 miles / 1:30h steady running) is that your slow twitch gets doomed at the end, so that you are forced to recruit fast twitch fibers for the slow running! That logic implies that Lydiard kind of stuff is based on having a lot of slow twitch for moving your legs around, which has to be obviously trained with slow steady state stuff – which kinda makes sense for these kind of guys. Now for any guy doing jumps or sprints (wether short or long) this won't be the case.
Other problem of a lot of sprinters is that they have a lot of mechanical problems while running at slow speeds (i.e. less than 20s per 100m), so having to run either fast or very slow. No wonder if you don't have enough muscle fibres that activate at the relevant speed.
Francis, Gerschler & co have shown that you can get a massive aerobic condition out of extensive tempo – and using Charlie’s logic "without killing your fast twitch", or better said, you will use / recruit your Type2a – because of running at its’ specific pace and - get mitochondrial development on it in order to make it last longer or recovery faster. and at the same time not overdeloping slow tissue and keeping the neural stimulus high. Type IIb fibers won't even be recruited at these slow speeds (70% of 100m PB). And thus you can take a sprinter to also succeed to some extent on longer distances. With LSD you would not be recruiting the type IIa fibers at all at the slower speeds and thus relying on the scarcely present Type I a/b fibres, thus moving forward like a snail.
I mean you can do LSD while having a lot of type II in order to target your type I tissue, but your limit will be achieved pretty quickly.
Further, CNS wise you will be moving around closer to race pace (i.e. for 800m). Thus better neural adaption.
BTW Dr. Thomas Stöggl (Universität Salzburg) has done some interesting research on HIT for running… for some groups it showed massive increases in VO2max as well as maximal lactate levels in blood. The control group used LSD training. The LSD group also made some very good improvements but with way more training volume. Max lactate in blood skyrocketed for the HIT group. Variance was big in both cases. Sadly no study investigates muscle tissue composition (Type I/II), but my gut feeling is that muscle tissue composition would explain the variance in the results.
I think that for someone moving up to to the 800m you can take the extensive tempo / interval based GPP (get up to 3-4 weekly sessions) for building the aerob base while playing around with distance and recovery time / type (walk vs easy / fast jog) and simultaneously keep KitKats more demanding trainings (3x3x300, 6x200, the 3x4x150 stuff) for CNS stimulation and speed development / maintainance BUT with more easy days in between as he prescribes, since you will be running above 50km per week!!!!
If Charlie Francis got his ideas regarding extensive tempo from the 40s/50s intervall training we will never know...
Obviously if you take a type Ia/b distance runner and make him do the interval based stuff you will wreck him pretty quickly!!!! Also the dilemma is what to do with someone who has 50%-50%... probably a mixed scheme multiple pace stuff like Coe & Co.