Flexibility and changes in training sessions..

I had planned one of my athletes, Mike, to ride this bike session today:

Cruise intervals.. wu) 20:00 build to ~1xx-1xx watts. Then: do 3 X 1' at 2xx watts on 1' at ~50 watts. Get warmed up and ready. .
Then: Ride 4 X 7:00 at 2xx watts.. no higher. If on CT then use stand alone mode. Race cadence of 85 revs. but as we discussed last time- change gears if you feel the need in order to maintain a higher cadence. The rest intervals are 2:30 and at 50 watts this time- recovery will be much more complete.
CD) 5:00 of very relaxed spinning.

This afternoon I received this e-mail from Mike:
Tim,
Wanted to get your thoughts on this morning's bike. Yesterday would have been a good day for a nap, instead, I worked 12 hours straight after my morning hard run. I was trashed last night and definitely carried some of that into today's bike. I changed from 4x7:00 to 5x5:00 when I realized I didn't have the mental energy to push 7' during the first set. That said, ironically, I think I felt better during the last set! Of interest, my HR tended to max between 159 and 161, my "presumed " LT being 156. Does that mean the set still achieved the proper goal as I ended up doing it?
Mike

My response to Mike:
Hmmm, first of all, fatigue had a major effect on the workout.
Changing to 5 X 5:00 is perfectly acceptable- you have to remain flexible! I used to simply start at my LT wattage (+10-20 watts) and hold it for as long as possible.. then rest for 1/2 the interval length.. then my next interval would be with the goal of completing the same interval again. Often times I would descend the interval times like: 12'- 10'- 8'- 6'- 4'. As the weeks progressed I felt that this workout was possibly the most effective for making me fast.
The goal of the workout is to boost your lactate tolerance- you can be assured that if you are holding the interval for only 5:00 at a near max effort then you are doing so.. along with some V02 benefit towards the end. The response to this, and ANY, session is never immediate and we want the over-all volume of work interval to slowly creep up. And it will.
My only recommendation would be to try and place the session on a day with less stress (and NOT on the day after a stressful day as is the case), but with that said I think you did great.
Hydrate extra today and include a little more complex carbohydrates like pasta, grains and breads.. you burnt primarily carbohydrate.
You are drinking Gatorade during the session too?
Tim

I have worked for Mike for ~4 years now and it has always been my goal to teach him how to train effectively, not just tell him how. Over the past year we have seen tremendous growth and maturity in both his racing and training. Every year he continues to get faster- and he's 49 years old! I know that part of this growth is because of what he did today. I have taught him to be overly cautious with fatigue and, thankfully, he follows through and is learning the difference between being tough and being smart. He's learned to be flexible and look at the big picture. One of my mantras with athletes is that "it's better to miss one session because you were smart, rather than 20 because you were tough"..