Do you have anything to keep you going? I am considering something like caffeine pills, to keep me going while I'm pushing myself now its the early and difficult days. I probably don't need to, but more energy never hurt anyone. What do you like to have before a workout?
For me, theres only 2 things that truly work... A nap. or Some of these breathing exercises: http://yoga.about.com/od/breathing/Yoga_Breathing_Exercises_Pranayama.htm Without one of the 2 above, my energy is almost always less at the end of the work day. You can take a red bull or something but depending on your rest the night before it may just be a short, ineffective rush. Also since I recall you saying you get anxious before training, that tires you out also. Youd be surprised how much stress and anxiety can cause you a "fake fatigue". In fact it can cause exhaustion without you even lifting a finger.
I know, it does tire me out a bit but not as much as you would think, I'm never angsting during training just for some reason I've gotten into this habit of getting a bit nervous, I don't know why! I don't get tired from this. I feel I am over-analyzing this.
Yea I'm not saying thats the only reason you may need a pick-me-up but a prolonged state of nervousness can cause you some fatigue...even if its just a little. But i made a thread not too long ago about lacking energy after a long work day so I know what its like to need something to lift you up. Try the breathing and there were some helpful energy foods mentioned in the other thread.
Bring extra water if you take caffeine. I know for myself atleast if I have any caffeine or sudafed (for alergies, which is also a stimulant) I will sweat a lot more than I normally do. I guess it is just because its a diuretic. Also maybe some protein and some slow digesting carbs preworkout. If you are working hard for an hour or more then maybe you are depleating all your glycogen stores and you dont have any energy left, so some slow digesting carbs before hand and some fast carbs as you are training like a sugar water thing such as gatoraide if you are training hardcore for a few hours.
I personally have a sugary fruit beforehand for a good carb. Something like an orange or grapes normally. I also take a multivitamin with my breakfast which is loaded with B vitamins. I cant remember the last time I've had caffeine and I've been doing two a days for the last two months and feel great. Make sure you get 8 or even 9 hours of sleep though.