I like the Gu gels. Salted Caramel is my favourite. I typically take one at the 8km and 16km mark.

I was thinking about this thread this weekend as I bonked on a tough trail 10 miler. With a more clear head and feeling a lot better this morning, I attempted to diagnose what all went wrong on Saturday and I came across this article:

http://www.runnersworld.com/nutrition-runners/science-behind-bonking?page=single

I thought it provided some very helpful insight into the timing and nature of nutrition. It doesn't provide hard specifics, but gives a good idea about the types of nutritional deficits you can create while running, and provides some clues about how you might prevent them. I think the biggest things though are judging time on your feet vs. distance of your run, what kind of run you are doing (race, training run, long run, trail run, road miles, etc), and your environmental conditions (I had an unseasonably hot and humid day and the aid stations did not have the things that I apparently needed to keep from half passing out and puking the last 2.5 miles of the race). And - my own 2 cents - be sure to experiment, I'm happy that I've pushed myself to all 3 kinds of bonking identified in the article. I know how they feel, and now I can build a solid plan for preventing each one.

jdelot wrote: »

If you don't mind carrying water, you can try Tailwind Nutrition. You mix it with 24 oz of water. I've used Gu in the past and never had a problem with it. But on my last 2 long runs, I've carried water mixed with Tailwind. A lot easier than opening a Gu Gel pak.

Thanks for this. I've been looking for like this to try instead of chews.

jdelot wrote: »

If you don't mind carrying water, you can try Tailwind Nutrition. You mix it with 24 oz of water. I've used Gu in the past and never had a problem with it. But on my last 2 long runs, I've carried water mixed with Tailwind. A lot easier than opening a Gu Gel pak.

I do better with sports drinks than gels. The added sodium of Gatorade or Tailwind is a plus for me on my long trail runs since I lose so much salt from sweat and sometimes have problems with cramping.

Came across this "article" about how various elite's fuel prior to/during/after marathons.

http://running.competitor.com/2013/08/nutrition/fuel-up-what-the-elites-eat_55730/2

Just my two cents.. I typically don't train with fuel, but I do use a gel or two when racing a half marathon. I don't enjoy eating gels, but it's undeniable that they help. I ran a half marathon last fall, and it was one of the best races of my life. I took a few shot bloks at mile 5, and then again at 9-10. I started more conservatively (6:40-50) and ran a huge negative split with my last miles at 6:15-20. Compare that to this spring. I was in arguably better shape, but just plain forgot to bring any kind of nutrition. I ran pretty even splits of 6:30 and felt amazing through mile 10 or so... then I bonked, running 6:40-50 miles in the end, and finishing 20 seconds slower. I finished both races in 1:25, but in the race with fuel I felt amazing with a fast finish, and in the race without I had to run through a lot more pain in the end. I say if your stomach can handle it, do the GU!

My favorite race day fuel is peanut butter GU and any kind of Clif Shot Bloks.

I didn't bother read all three pages of this thread. So my apologies if I am repeating information given out.

A few said that supplementing with gu in the HM distance is not necessary. I tend to agree with this, but it all comes down to 3 things.

Your fitness level, the pace you running your half at, and how long it takes you to actually run a HM. If it takes you over 2 hours to run a HM and you are breathing heavy for most of it (indicates a very poor fitness level) then yeah you may exhaust your glycogen stores and will effect your performance. In this case, I would not focus on Gu's to improve your results. I would focus on improving your fitness level by continuing to run your long runs with a comprable distance to be under 2 hours at a conversational pace. That may mean running 10K's instead of HM's for a while.

Usually, this is not the case and as Sonic mentioned earlier, any gu or other supplemental nutrition you eat during your race is more mental than physiological.

The reason you eat things like gu's, gels, jelly beans, McDonalds biscuit sandwhiches (OK not the McDonalds), is to supplement the exhaustion of your glycogen stores. The pace you run a HM should not be so fast that you are running it predominately on your anaerobic system. In other words you are breathing like a mad man or woman most of the time. If you are, you are running too fast. This is not your HM pace. In other words, the shorter the distance your race is, the faster pace you should be able to run it at. Your 5K pace is faster than your 10K pace which is faster than your HM pace which is faster than your marathon pace. If you run your race at too fast a pace, you blow up because you went way beyond your lactate threshold, not because you burned up your glycogen stores. Gu, gel, beans, and breakfast biscuits will not fix this. Improving your lactate threshold will.

We all have a certain fitness level (it's different for everyone and you can improve it), where you run a certain pace at which your body will stop being able to use the oxygen you breath in (aerobic) and will force to burn energy (sugar) in your blood without oxygen (anaerobic). As soon as you reach this pace, we say you reached your lactate threshold. Once you run a pace that goes faster than this threshold you begin to dramatically increase the amount of lactate and hydrogen ions (byproducts of the anaerobic process) and make your blood too acidic that you can no longer maintain this pace. A good runner can race exactly at their Lactate Threshold for aproximately 1 hour. Any faster and their performace drops big time. Again, gu's, gels, and other nutrition does not help in this case.

The only thing you can do to improve this is training. Running tempo runs in training at your lactate threshold will stress your body to improve it's capabilities to clear lactate and hydrogen ions. Over time, your lactate clearing capability improves and thus raises your lactate threshold. Also longer runs at your conversational pace (70-80% of your max heart rate) will stress your other aerobic functions. It stregnthens your heart so more blood can be delivered to your muscles at every heart tick. More blood means more sugar and oxygen will be flowing to your muscles. Your body will increase the amount of hemoglobin in the blood (its what carries the oxygen from your lungs to muscle cells in your blood) and increases the amount of mitochondria in your muscle cells (its the oxygen burning part of your muscle cell).

Again, all these improvements happen as a function of training, not fuel source (gels, gu's, beans) during your race.

Now, when you run the marathon distance and beyond (beyond 20 miles or a distance that takes you more than 2-1/2 hours), your body will slowly burn all your glycogen stores. This is when suplementing with fuel while on the run will help. As soon as your glycogen level runs severely low, this is when you hit the famous wall or "bonking". Training at slower paces for long distances helps train your body to rely more on fat burning and thus conserves your glycogen stores which means you can run farther on the same amount of glycogen stores. Proper nutrition days leading up to the marathon helps (carb loading) to maintain a high glycogen store going into the race. And there are studies that show that early on in your marathon training, if you do your long run fasted, you can actualy boost your body's capability to store more glycogen.

Hope this helps. let the negative comments commence. ;-)

The physiological adaptation to glucose spikes is called diabetes. Not a good thing.

sinister2014 wrote: »

Stoshew71 wrote: »

Your fitness level, the pace you running your half at, and how long it takes you to actually run a HM. If it takes you over 2 hours to run a HM and you are breathing heavy for most of it (indicates a very poor fitness level) then yeah you may exhaust your glycogen stores and will effect your performance. In this case, I would not focus on Gu's to improve your results. I would focus on improving your fitness level by continuing to run your long runs with a comprable distance to be under 2 hours at a conversational pace. That may mean running 10K's instead of HM's for a while.

interesting take.... look at the results of a large half marathon and you're going to see ALOT of people that are over 2 hours.

I also see people that run marathons in 6 hours. I like to run, but good Lord I do not find being on my feet exhausted and hungry for 6 hours fun at all. (I will never make it as an Ultra runer) I have no idea why people do that. But I see them with smiles on their faces when they come in towards the finish. They are probably just too happy that it's all over.