Q:

Can't sleep at night after workout

I've been going to gym for more than 10 years (I far away from being professional though). Recently (about 0.5 - 1 year) I've started noticing, that often after gym I can't fall asleep. Even if I really want to, even if I feel really tired and sleepy.
Most of the articles I read are talking about working out just before going to bed, but in my case it is not like this.
For example yesterday I had a "gym day" after couple of weeks vacation. I went there at 5 p.m. and finished already at about 5.40 p.m. It wasn't too extensive or hard. After workout I drank a gainer and ate a dinner after couple of hours (at about 7.30 p.m.). At about 9 p.m. I drank a tea with some cake :$ (when I don't go to the gym and drink tea in the evening it does not affect me). And at 10:30 I have turned the lights of in my bedroom. I could't fall asleep until about 1 a.m. and after it was not quite clear if I was sleeping or not.
I doubt it is something to do with my nervous system, but I am not sure how to deal with this problem. Any advice or opinion is greatly appreciated.
Update after 8 months: an amazing thing I've discovered for myself after consulting with my doctor is simple Magnesium - helps to calm down/relax and fall asleep. Also has some other valuable characteristics for your muscles. Google, read, check with your doctor and try it!

A:

Don't working-out right before trying to sleep.
Most people need a couple of hours to cool-down after exerting themselves before they'll be ready to sleep. In your case, it appears that has been fulfilled - 5:45 to 10:30 should be plenty of time for your body to ramp-down and be ready for sleep.
Unless, of course, you consumed a stimulant like caffeine. Depending on what type of tea, how much you drank, and what your caffeine tolerance is, that's a much more likely candidate than the workout. 
Skip the tea/coffee/soda in the evening. Frankly, you can probably get rid of it altogether and you might feel better. (After the withdrawal symptoms pass that is...) 

