When marathon training, are GU or other solids helpful or detrimental during long training runs?

gelindo wrote:

You get good at what you do, if you take one during training you probably should plan on it during races as well. I've been running for a lotta, lotta years and have done long runs both ways and much prefer to have a GU than to suffer through the last few miles of a two and a half hour run.

I've also found that when you make yourself suffer through depletion it makes for harder recovery the next day or two. I'd rather drink gatorade or take gel/water and then be able to recover faster and put in a decent effort the next day too.

....why is it always one or the other????

How about sometimes yes and other times no....

"Sipping every 5th minute in every run over 60 minutes? "

Yeah? Who the heck is doing that??? Maybe that's why some people wear those camelback things.

a bit tough, for sure! it's basically what you encounter in a marathon though with fluids every mile. point is, get used to it.

GU= Incredible.

remember that next time the GU-eating guy beats you in your next race.

Actually, that's not really true. . .especially during sleep, your liver glycogen stores are being used (and nearly depleted) by the CNS.

hadn't heard that before. how many calories does one tend to burn when asleep though, about 50 or so an hour? that's only about 400kcal if one burnt exclusively glycogen. any more detailed info on this, it's interesting.

if you people don't replace calories during the run, what do you all use for electrolyte replacement during the run? any recommendations on drinks or pills that can be used with water?

Just water. Lick your arm for salt.

Alan

Shaggy wrote:

if you people don't replace calories during the run, what do you all use for electrolyte replacement during the run? any recommendations on drinks or pills that can be used with water?

I like the Emergen-C electrolyte mix, because it has a nice variety of electrolytes instead of just sodium or sodium/potassium. Plus it's effervescent which seems easy to absorb - though I admit I have no clue if that makes a real difference or not. I think the body is pretty good about sucking electrolytes out of any solution you put down when it's deprived.

Great thread, I've been mulling over these questions for quite a while now. For what it's worth, I made great strides in ability when I stuck to a regimen for a while of weekly long runs with nothing but maybe some water. I still do that mostly, though I've tried taking some things during training before marathons, but either way if I load up on stuff right after I finish I recover pretty quickly.

The bummer for me is my gut cannot handle sucrose/Gatorade kinds of drinks, so I've been using GU2O (complex carbs). Since I'm not elite enough to have my own food bottles on the course for a big marathon, and they usually only serve Gatorade or something like it, I can get in trouble there.

jwiley wrote:

hadn't heard that before. how many calories does one tend to burn when asleep though, about 50 or so an hour? that's only about 400kcal if one burnt exclusively glycogen. any more detailed info on this, it's interesting.

Yep, liver glycogen stores can be severely reduced between dinner and breakfast even if just resting. Liver glycogen is the primary source of glucose for the brain.

"Depletion" might be overdoing it, but certainly a reduction.

Lore of Running has liver glycogen losses around 50 g.

The following says 50%

Since the liver holds about 100g, they are both consistent.

jwiley wrote:

hadn't heard that before. how many calories does one tend to burn when asleep though, about 50 or so an hour? that's only about 400kcal if one burnt exclusively glycogen. any more detailed info on this, it's interesting.

In my grad nutrition, they told us you use up ~85% of your glyocogen stores in your sleep. Of course, endurance athletes have much larger stores, so they likely use up a smaller percentage. This is why breakfast is so important, particularly before a race.

jaguar1 wrote:

jwiley wrote:

hadn't heard that before. how many calories does one tend to burn when asleep though, about 50 or so an hour? that's only about 400kcal if one burnt exclusively glycogen. any more detailed info on this, it's interesting.

In my grad nutrition, they told us you use up ~85% of your glyocogen stores in your sleep. Of course, endurance athletes have much larger stores, so they likely use up a smaller percentage. This is why breakfast is so important, particularly before a race.

I am not sure the liver glycogen in athletes is any greater than that of ordinary folk. Muscle glycogen, absolutely.

I agree about breakfast of some sort.

I never understood the "tough guy" mentality. It's not "badass" to not drink water during training. Doing that nearly killed Alberto Salazar during a 20-mile road race (and possibly caused permanent brain chemistry damage during Boston '82). No one has produced any scientific studies yet that indicate that hydrating or taking in carbs on long runs is detrimental to training.

Even if they could, ALL that it would prove is that marathoners should train without replenishment. It would have no implications for runners training for shorter distances. Even if taking in carbs and water on long runs reduced your body's capability to store glycogen, it would ONLY have implications for races over ~20mi. So half marathoners on down could refuel during long runs.

As I said, as of right now there is NO evidence to indicate that refueling reduces your glycogen storage or fat utilization capacity. However, there is plenty of evidence that training and competing in a dehydrated state is not optimal. Pretty much all other athletes refuel; why shouldn't runners?

A few goods points.

First, not drinking water is just plain stupid, regardless of conditions. I've never heard anyone (since 1950) advocate limiting water intake. I see that a few posters here limit water intake, but I have never heard that advice from any reputable source.

Second, the same probably could be said for electrolyte replacement. You can't "train" your body to make up for missing electrolytes.

Third, the above post is right on. The only possible reason to limit GU or food intake would be if you are specifically trying to adapt for a marathon. Even then, there appears to be considerable debate on whether limiting food intake even works results in adaption. But there would be no reason to limit any solid intake for any other reason.

Ok. Riddle me this. If refueling does not reduce the training stimulus, then what is the purpose of the long run instead of two runs of half the length?

turkey leg wrote:

Ok. Riddle me this. If refueling does not reduce the training stimulus, then what is the purpose of the long run instead of two runs of half the length?

I get your point. But I will riddle you this: Wouldn't the ultimate stimulus be a long run after no eating or drinking for the preceding two days?

turkey leg wrote:

Ok. Riddle me this. If refueling does not reduce the training stimulus, then what is the purpose of the long run instead of two runs of half the length?

The training stimulus does not come merely from lack of glycogen. It also comes from cumulative, relentless pounding of 2+ hours on your muscles and the adaptations they make, regardless of glycogen levels.

But that aside, it is good that you now appear to understand just how overrated long runs are.

turkey leg wrote:

Ok. Riddle me this. If refueling does not reduce the training stimulus, then what is the purpose of the long run instead of two runs of half the length?

A long run will fatigue the slow twitch muscles such that you need to recruit the faster twitch fibers. Those fibers are then stimulated to become more oxidative.

Doing 2 shorter runs may not accomplish the same task.

I would also argue that the long run is something of a mental thing as well. I believe that you need to get used to being on the run for a long period of time.