Everyone's needs are probably different depending on the activity, effort expended, and climate.

If I run longer than one hour, I need to have something because I start to feel STARVING.

Also I am ultra-careful about hydration and electrolytes (on a doc's advice) because I have a history of fainting that the doc says is partly due to "low volume" since I'm a lightweight. He says when other people might say "I don't feel so good," I simply go down. Thankfully since learning my "triggers" and paying attention to hydration/electrolytes; I haven't had any problems in several years.

I like the Hammer products and use the Hammer Heed drink primarily. In the past, I used the Hammer gels on my longer runs. Right now, I'm using a protein bar cut up into pieces and I eat a piece when I get the "hungries,"  This is working for me now along with the Heed.

 

I've been told by a running coach that gels are not just for making it thru a longer distance, they also help with recovery afterwards. He said to take one every hour. It takes me about 2h25 to run 21 kilometers.

I've experimented with them: I've done it with and without gels, with water only and alternating with sports drinks and I've varied when to take gels.
Not taking them at all leaves me really tired and hungry at the end and make the last kilometers feel like a chore. Even if I'm having sports drink while running instead of water. Didn't enjoy those runs. But the sports drink did make me feel better, compared to running with water only.
Taking gels every hour (about 8-8.5K) as suggested by the coach I felt fine. Wasn't hungry and plenty of energy.
Taking one gel around the 10K mark (where there would be a water station in a race), was also fine to finish the race comfortably.
I haven't noticed a difference in recovery after the race with just the one gel or two gels.

I guess it all depends on the person. What works for me might not work for you.

Disclaimer: I don't only run. I also do strength training a few times a week. Maybe that makes a difference too?

I typically don't need anything for a half marathon, can't even take in the diluted Gatorade when running a race.  Now as I am training for a marathon, I can see how this could be a problem and probably need to plan on taking some gels.  

A couple of times when I ran up to 3:00 hours on a 16 mile trail run, a gel or 2  at about 2 hours gave me a short boost, probably more mental, but  that still helped.

Accurate or not, it seems obvious to me that race day nutrition and the in-race fuel strategy are all highly individual, something to test and learn during training runs. 

Trent wrote an excellent summary of race fueling over in another forum, it may offer some additional insights. Link to Trent's RA posting

Interesting read. I have to reread this when I have more time. Thanks

Me too - must read whan I have more time - but the first line probably reflects where I'm at:

 

"Depends on your effort; but at a submaximal pace you should not need any calories for about 15+ miles if you have been eating adequately."

 

the key phrase being "eating adequately" - which I know I don't - and so I don't believe I have much stored - that's the way it is. 

 

MTA: Read what Trent wrote -  interesting info - makes me want to learn more about this side of things.

 

Apparently I get hungry because I'm running too damn slow In my defense, I have to run slow if I want to control the bursitis flare-ups at this point. I also probably get hungry at about an hour into the run because I've run out of stored glycogen, which makes sense. As I understand the article, if my "training" was more effective, I guess my body would then switch over to burning fat and I wouldn't be hungry.  I'm just under 20% fat, so I do have some available fat-fuel.  I guess I'll have to read up on how to improve my training since I would really like it if I did not get hungry while running.

Happyfeat, I don`t think you could possibly need gels or use up your glycogen stores on a 1 hour run.

I do know other women who weigh 100-110lbs who do not have this problem, so I don`t think your small stature or slim build could account for this problem. It might be best to ask your doctor about this to get a professional opinion.

I am certainly not an expert in this area, but have read about the subject in several sources including Noake`s `Lore of Running`, and it seems Trent`s post confirms this.

 

I can see that getting dehydrated more quickly than most people could be part of the problem. 

I have always understood smaller runners have an advantage in hotter or more humid weather because the ratio between their surface area and body mass is more favourable, though this would mean better cooling through having more area to sweat relative to body weight, that would imply using up fluids more quickly.

 

Anyway, an interesting area for study and individual experimentation.

My experience in this half: not necessary.

 

Just thought I'd comment on this now that I've done my race. I opted to carry my 500ml waterbottle with a 50-50 mix of water and Powerade bc that's what I used in training and I wanted to make sure I could drink when I wanted, not when there was an aid station. Race day wasn't hot; starting temp about 8*C and finishing temp about 12*C. My limiting factor in the last 2 miles where I struggled was not hydration or hunger; it was physical strength in my legs. I think that's more about building core and leg strength than anything I could ingest in the race.

 

Thanks for all the thoughts on the topic when I asked.