Is Daniels' phase IV optimal ?

Daniel's workouts don't give you much practice at your 10K pace. The T pace is too slow and the I pace is to fast.

I throw in some race pace workouts like 6x1mile @ 10K pace w/ 1-2min rest or 5x2000m @ 10K pace w/ 2min rest.

That gives me experience at my 10K pace and are good tune up workouts before I race.

Agree with the poster above. I like to do some race modeling workouts 3 weeks out and 2 weeks out and then just do some easy threshold work race week. I would probably do something a little different than the 10,000m worth of straight work at 10k pace than the poster above - reasonable people can reach different conclusions sometimes. I really like things like 3 x 200 at mile pace with 200 slow jog recovery followed by 4 x 1 mile at 10k pace with 2:00 rest, followed by 3 x 200 again, with 3:00 rest between sets. Or 3-4 sets of 200 at mile pace, 200 slow jog, 1600 at 10k pace, 200 slow jog, 200 at mile pace with 3:00-4:00 rest in between. Those workouts get your work at race pace, but they also simulate what you will likely experience on race day - getting out quick to establish position, settling into pace, then finishing with effort. And I like to keep the volume a bit lower just to freshen up some since the fitness gains have already been established for the most part.

Agreed with all said. Daniels' training plans are fairly generic (hence the "5k-15k" designation), and earlier in the book he mentions Phase IV is a good time for specificity.

I also think that these race specific workouts (and their variants) are worth being incorporated in phase IV.

Would you do two race specific workouts per week or would you mix it with another workout focusing on other paces, maybe to tackle some weaknesses before goal race ? Or would you just try to alternate between R, I, T or mix them in one workout to maintain adaptation until goal race ?

What do you prefer ?

Q1 10k specific

Q2 10k specific

Q3 L/M

Q1 10k specific

Q2 R,T,I all in

Q3 L/M

Q1 10k specific

Q2 R/T/I

Q3 L/M

I tend to stick with one track session (race specific in this case), one threshold run and one long run, until race week, when I just do an easy threshold workout. My long runs will also drop in length the last week or two before the race, and the volume of threshold work will also come down.

I agree with Smoove here. I would do one track workout at 10K race pace, one tempo run not to exceed 30 min, and one long run until a week before when I start to taper. The idea is to be fresh and sharp going into the race

Google: Timman Critical Velocity

Thus, this critical velocity corresponds to 90% VO2 max, and is the minimum velocity (the safest) to develop glycolytic muscle fibers. It is also known that VO2 max can be trained by running between speeds corresponding to 90 and 100% VO2 max.

Of course, it is right to target some pace in order to get some general physiological adaptation. However, I believe that there is not only a discrete set of speeds (threshold pace, critical velocity, v delta 50, VO2 max, ...) to focus on, but rather a full spectrum of speeds, each one being associate with a very unique and singular physiological state combining a definite amount of blood lactate concentration, a definite percentage of VO2 max, a very unique stimulation of muscle fibers ...

Therefore, I think that using workouts mimicking race condition allow the body to adapt to the narrow range of speeds used in a race. Of course, this is not the best way to focus on a specific physiological adaptation such as stimulating glycolytic muscle fibers, but it is the best way to adapt to that the physiological effects produced by this pace.

Of course, this approach has some limitation because otherwise you would just need to run at race pace all the year round to perform well ...

Do you agree ?