Hey runr, no need to apologise to me for anything. I was just pointing out that you were coming across somewhat "defensive". No need to feel that way.
Here's an axiom to live by: if your athlete is not able to perform as you expect, you do no harm by backing off on all intensity and doing purely easy aerobic running until you discover the cause. The performances of a well-aerobically-trained runner do not go "down a hole" for nothing. If he is not well-trained aerobically his performaces can plummet very quickly in the season.
Right now, I would be doing the above with your runner. Just lots of easy miles.
Up front, although there doesn't seem to be too much wrong in the example week you give (except for Tues, which I'll get into), I still maintain that you should be doing more to learn how easy/difficult each type of run is for your athlete.
I would slap a HRM on him and go for one of his "easy" runs with him. If his pulse climbs above say 150, it's no longer easy.
Same with the steady run. Find out how tough that is not simply by running with him (the pace might be a holiday for you), but by getting an HRM on him. I would even have lactate tested him, but there is no need for you to feel you need to go that far. Knowing his HR should tell you all you need to know.
Go by this; it's simple and very effective.
Find his max HR by warming him up for 20 mins with a couple of 100m strides then giving him 2 x 800m hard with only 3 mins recovery. He is to drive the last 400m of the second one for all he is worth. The highest number he sees on the HRM you can take as his HR max.
Then do this:
Easy running is Max HR - 50 bpm (eg: 200-50 = 150 or less. Never higher.)
Medium running is Max HR - 40 bpm (eg: 200 - 40 = 160 or less. Never higher.)
Tempo running is MaxHR - 30 bpm (never higher).
I am confident that your guy is not running this easy. So his easy days are more likely turning into medium days. That, plus the tempo/interval days is driving him into the ground.
Let's consider those harder days. When an athlete runs on a treadmill, it is customary to elevate the treadmill some 1-2% to compensate for the lack of headwind in the gym/lab and more closely simulate normal outdoor running conditions. When a runner is doing a VO2max test, it is also usual for the treadmill to be elevated by a certain amount in each of the latter stages to help the athlete reach a VO2 peak.
So a runner might get to 6.00m/m on a flat treadmill, then 5.30m/m, then 5.00m/m, and then if he has still not reached max, the treadmill speed will be reduced to 6.00m/m but the end of the treadmill will be raised by 4%. Then 6% (for around 1 min 45 secs each stage) then 8% and so on.
The point I would like to make is that although a 4% elevation does not look like much, it FEELS like it to the runner. In fact, 6.00m/m @ 4% is every bit as difficult as 5.00m/m on the flat. A 6.00m/m pace on the flat that might cost the runner 145 HR, can require 20 beats more (165) when running up a 4% incline.
Now anything that you term a "hill" is more than 4% incline. If it was a 4% incline, you would not term it a hill. So, bearing in mind what I have just explained, what do you think is the actual cost to your runner of sending him 800m up this hill at what would be 5k pace on the flat? Very likely he is hitting max HR long before the top of every rep. And he does six of them. Bad news.
This is then followed by a "steady" run the next day (which I believe is actually being done more intensely than it should be, it should be an absolute JOG after those hill reps the day before), and then a "tempo" run two days after that.
This is a tough week: Tues / Wed / Fri all hard to a certain extent, especially if his easy is not easy.
If he is training at the right intensity on all his runs and recovering in between, then this is not too tough a week. If he gets the intensity wrong even a little, or just doesn't recover from one day to the next, he can get into a downward spiral that is tough to pull out of. That's when his performances suffer. Which is where you are right now.
Get a HRM on him and see how "hard" he is training every day. I have given you HR guidelines to follow. Get him on them and he will soon recover. Make a point of understanding the relevance of each training pace to HIM. How much is it costing HIM (and don't compare him to what others are doing).
A number of other posters here suggest the problem might be psychological. I don't believe so. Of course it can become psychological if his physical condition deteriorates to such an extent that he gets to a state where he "cannot face" another tough session or a race. But the underlying cause is physical, not mental. Understand that overtraining causes a number of physical problems; altered mood, altered sleep pattern, upset digestion, reduced immune system... It is easy to see how anyone with such problems would not be able to perform to his/her best in a race, and indeed, not look forward to racing, but the cause is physical, not mental.
In the end, you know the runner, and can answer better than we can.
Now to go on to your other questions on speeds and recovery...
Mark Wetmore apparently said in a recent interview that coaches should try and learn as much Ex Physiology as possible. I recommend you follow his advice as much as you can.
Instead of wondering about paces for reps and length of recovery, you need to understand what each type of run is trying to achieve. If you understand that the body has to adapt (change in some way) in order for the runner to improve, then what part are you trying to "change" with repeat 400s? With a tempo run? With a long run?
I'm not being coy, hiding some sort of "secrets" from you. But a simple question such as "how much recovery" can involve so many variables that it would be rash of me to quip "45 secs jog" and off you go to implement it.
For reps of longer than 2-3 minutes (up to 6-8 mins), you are trying to improve aerobic capacity. IF THERE HAS BEEN ENOUGH AEROBIC BASE TRAINING these are carried out at paces from 3000-HM. The length of the recovery is not vital. Just ensure the HR is back to around 125-130 before the next run. Sessions such as 2 x 3000, 3-4 x 2000 or 4 x 1600 or 6 x 1000m are all common. The longer runs are obviously slower. If the athlete is finding these easier in a few weeks, DO NOT run them any faster, just lengthen the run.
For shorter 400-type reps, there can be 2 types: slower pace with shorter active recoveries and faster pace with more complete recovery. In the first, you do not want to let the heart completely recover to 120, but should jog 100m and go again once it drops to around 140-145. Pace might be 3000m pace.
The second type will be faster but with more complete recovery when the object will be to improve tolerance to the rising blood and muscle acidity associated with race pace. This will be performed mid-to-late season.
But none of this will be of any value if the athlete is not properly aerobically prepared. Read anything you can find on Lydiard for some fundamentals on aerobic conditioning, and then make sure they are being applied correctly for this (and other) athlete(s).
Hope this helps.
Damn, I have got to give up these long posts!