can you expand on what the difference between these is? 
The running high knees would be more of a focus on knee lift with the foot coming more or less in an up and down action, while the running As still have the same high knee but also have a heel recovery under the hips and more or a cycle action stepping down with the foot.
In simple terms the running A is more like running (cyclical action) while the high knees are a bit more like driving (piston action).
Thatās right, straight up under the butt and not flicked behind like some still do. 
Because you donāt have the travel through the air of a running stride, I always kept the foot directly below the knee at all times and i didnāt have two different types.
OK I had a look thru the SPEED POWER video to review the technique and I have been looking at it as pretty much where you go into the B from the A. This really works the hammies done in this way so I guess it is a variation on a theme to possibly use in the combination sets.
charlie, what dictates how far the split runs should be? i mean if I want to break down the 2x300m session of spec end into say 2x5x60m with 90s/20 mins recā¦but when should it be 2x3x100m with 90s/20 mins rec? does the length of the split run mainly depend on the age of the athlete and how fast they are? I mean the slower the athlete the shorter (down to 60m) should the split run be? I guess it also depends on how much room you haveā¦
Is there a thread that discusses the application of split runs? When to start using them, what the intensity levels are, how to split them up, etcā¦?
depends- S-to-L? L-to-S? Indoors for some of the SPP? Generally, the more you expect performance to shift (an honest assessment!!!), the shorter the splits might be and the higher the athleteās level, the longer theyād start out- cause thereās less performance difference possible.
So, when thereās lots of room for improvement, you might start 300s as 2 x (5x60). Top athletes might start 2 x (150+150, or 200+100). In any event, by the end of the SPP, you obviously must be able to complete the whole run, so you need to figure what your progression will be to get there.
you can check out the SPP lecture series to help with your planning.
Iām having trouble planning my S to L GPP. I have everything else down but this will be my 1st year using a S to L and I am stumped.
i am going to do the L-S for spp starting in late october. why are the first 4 weeks of the thursday workout hills? is it possible to do 600s or 700s as a replacement if hills were done in the gpp?
Do you have the GPP download? That should help
The GPP and SPP are not clearly demarkated, rather, they blend together smoothly to create the least physical disruption and training stiffness. The hills in this case blend from a GPP but thereās no reason you couldnāy go with 700s etc if you adjust the GPP backwards to match up (this will probably mean shortening the GPP)
blending is definatly what iām doing. right now the thursday workout is 2x400+400 with 1 min rest btwn reps and 15 minutes btwn sets, or splits 800s, whatever you want to call them. i avoid running the straight 800 since i am more of a 2/4 guy. i did this last year and it worked out well with a smooth transition into the 2x600 (using your other L-S program).
Right now i am doing short hills on tuesday and long hills (KitKatās workout from LT thread) on Saturday. i plan on going into 700s for the first week or two of spp and then going into the 600s. although last year i did the 2x600s for like 7 weeks in a row with improvemnet each week, went from 1:36 to 1:29, so i would not be hesistant in doing that again as well and not even doing 700s, 600 is the farthest i like to go.
Approx. how many weeks of GPP would be done prior to the particular SPP provided in this thread? (Either or both programs-S to L and/or L to S.)
At a higher level as this is (50.22 female at end of program) the GPP was a bit short- more because of a very late start to the program but normally it might be a 5wk GPP.
Charlie, so would it be wise to go into the L-S after completing S-L indoors for a 400m runner?
Hi Charlie
If the 400 s-to-l has just one spp of 12 weeks and the gpp is 5 weeks and assuming that training commences at the beginning of October then competition would begin around end of January in time for the indoor season. Does that mean we should repeat the spp for the outdoor season?
I am not Charlie, of course, but in my opinion it wouldnāt be wise. You could switch from season to season, if needed.
You can be very creative and productive with S-L SpecEnd emphasis from indoors to outdoors. Particularly if the training year extends into summer comp. Of course much would depend on maturation of the athlete and technical compliance with the event, IMO.
The SPP and '04 Vancouver downloads provide some good insights and criteria for such direction.