As you race more/train more your energy level will pick up. When I 1st started I was dead for the day, now after a long run or a race it is just like any other day. It just takes some time for your body to get use to the racing/training. A good recovery drink with something like a 4-1 ratio of Carbs to Protein. Books would have you consumes about .5 grams of Carbs per lb to your body wt with in 30 mins and 10-20 grams of protein as soon as possible for recovery and after 2 hours repeat the carbs.
I agree with the previous post . I like Fluid brand recovery drink. I make a water bottle of the stuff and take it with me to the race, leave it in the car and drink it after the race. I also like Stinger protein bars.
However, I think you need to take a step back and look at your pre-race preparation. Are you getting up early enough to eat a light meal (something like a bagel with peanut butter), drink coffee, take care of nature's call, etc.? Are you going to bed early enough the day before? Do you lay out your running gear the night before? Are you warming up adequately -- including an easy warm up run and some strides at race pace -- before the race?
Also, are you cooling down properly after the race? Are you walking, taking a slow, easy recovery run? Do you use a foam roller after the race? If you're sore, are you taking an ice bath (something I dread)?
Also, some races leave you trashed. It's a problem only if EVERY race leaves you trashed. That may also indicate overtraining (another word for "under rested").
"Victory through attrition!"
Charleston Half-Marathon 1/15/2011 -- 1:52:03
The Scream! Half-Marathon 7/16/2011 -- 1:56:00