I think you'll know based on your energy level.  I run about 3-4 hours after lunch and usually have something like a banana 30-60 minutes before I run.

i think you can run without eating FOOD for running 5k

gatorade is fine for running that distance

taking gels for running 2.5 miles??? thats very excessive.

eating before running is a major no/no in my opinion

i did the C25k a few months ago

then did a 10k race last month..i did it in 50 mins

I'm a mom of 2 kids and love to run....I'm competitiive...appeciate others opinion..

My goal is to run a 5k race in 35 mins!!!

Colleen

I'm starting Week 4 today and I usually don't eat a thing before I run. With my current schedule, I usually run about a half hour after I wake up so I'm usually refreshed and ready to go. My stomach feels empty but I'm not overly hungry at this time so I find that I can go for my run and then have breakfast after I return and cool down. The reason why I don't eat anything before the run is because I find that I start to feel a bit sluggish (as the body is also starting the digestive process) if I do any activity after eating so I don't want to risk the same thing happen while I'm running. Something small (like an energy bar) should be fine if you do have the need to eat something. Just make sure it's nothing too heavy.

This snippit on About.com pretty much sums it up: Should I eat before I run?

Hope this helps!

Just to clarify, I never said anything about taking gels for short runs.

Yep,. I figured that....was more clarifying for newbierunner.

you have to do what works for you - I like to make sure I eat well the evening prior to a run and them eat nothing or very little - 1/2 a bowl of cereal or a banana , slice of toast - before the run. over 6 miles and I take gu at the 1/2 way point. over 10 miles I Gu every 4  - 5 miles. Some people don`t eat but drink gatorade of slug a gu before the run. I take gu because there are water fountains all over my route and they Gu is easy to carry - you may find you prefer gatorade.

If you are getting light headed or feel faint or weird toward the end of the run you probarbly need to get more food in before you start.

Even though so many people have chimed in about what they eat or not before running, here's my two cents.  I started out like you, small distances at first and I went early.  I did just fine with nothing to eat, wasn't hungry so I didn't eat (except I drank about 8 oz of water).  For the slightly longer distances (5-8 miles) I started hitting "the wall".  So I did start to eat a complex carb like oatmeal or whole wheat bagel with milk or oj.  That helped a lot.  Now, in addition, I do take a running bottle with water and packet of shock blox (I think that's the name).  I still hit the wall, at 7+ miles,  but I just push through it.  Don't give up on that running.  You'll figure what you prefer along the way, just don't let a few obstacles stop you - HAVE FUN!