Hard to concentrate after strenuous exercise?

Whenever I am doing regular training I noticed that if I do a solid session of exercise, particularly in the morning, that I feel badly spaced-out during the rest of the day. I used to do a bit of climbing, and I used to go in the late afternoon at the Mile End wall, but it basically meant that I would write-off any meaningful work during the rest of the evening.

So post-exercise, I could potter about and procrastinate, but anything requiring concentrated focused effort was almost impossible. I thought it odd that other people, such as those I climbed with, didn't experience similar degradation in concentration.

But since then I've noticed that some other people were reporting similar issues of loss of concentration on a cycling forum, so I googled for the issue, and it seems a common complaint;
"s5fskzfv" on Bike Forums said: "After a long workout I often have trouble concentrating. It's hard to describe exactly what the problem is, it's like if I have something I need to read, or something that takes thinking like balancing a checkbook, I just don't feel like doing it. Trying to concentrate feels uncomfortable to the point that I can't do it. I tend to do a lot of reading, if I didn't, I might not even notice the problem, it's sort of subtle. I'm not sure exactly what it is, maybe not enough sleep or low blood sugar? Usually by the next day I'm back to normal after a couple of meals and some sleep."
NaturalBeasting talking on Testosterone Nation made this post:
"It is extremely difficult for me to do critical thinking after a really ball-busting tough workout. I completely space out and can't focus.

This effect usually lasts for the remainder of that day and sometimes 1-2 days afterwards. (It affects my performance in school/work.)

If I don't workout for a week or so there's a dramatic difference in my mental capabilities.

It's been happening my entire life, despite good sleep, nutrition and overall health.

Anyone else experienced this?

And "strawberry" asked this question on yahoo Answers:

After doing my morning exercise I can't concentrate in lectures..will I just 'outgrow' this?

 I'm 22. I love my exercise. In my summer holidays (I'm at uni), I always start my day with a half-hour workout. But if I'm in the middle of a university term, I find that after doing my morning workout, I find it difficult to concentrate in lectures due to feeling tired from the workout.


So today, I did a short run and some weights, after a bit of a layoff, and right now I am feeling completely unable to work.

I've eaten a good breakfast since, so I don't think that low blood sugar is the issue. Unless its some sort of "hangover" effect. I don't feel tired right now, and I wouldn't be able to doze off, which is unusual for this time of day, whereas normally I could easily have an hours kip.

There are a few theories on the acute changes brought by exercise, both aerobic and muscular;

for example copper and zinc blood levels;
http://www.ncbi.nlm.nih.gov/pubmed/24509996

Elevated brain-derived neurotrophic factor levels;
http://www.ncbi.nlm.nih.gov/pubmed/24495613


This paper seems to suggest, that you benefit from CV fitness, but not from the exercise itself;
These findings suggest that cardiorespiratory fitness, but not acute aerobic exercise, may be beneficial to behavioral and neuroelectric indices of action monitoring following errors of commission by increasing top-down attentional control.

If anyone has got any suggestions on how to alleviate this problem, I am perfectly happy to try them out! (In the name of science)

References

http://www.bikeforums.net/archive/index.php/t-791130.html

http://tnation.t-nation.com/free_online_forum/sports_body_training_performance_bodybuilding/reduced_mental_capacity_after_a_tough_workout

http://uk.answers.yahoo.com/question/index?qid=20111023102110AAZx0Kw


http://www.ncbi.nlm.nih.gov/pubmed/16713115