Marathon - glycogen management while running

Blue Steel · 29-10-2014 5:39pm #1

I read that taking too many gels can also cause low blood sugar if you don't hydrate properly/enough because the gel is stuck in the stomach and doesn't go into the bloodstream.

Is this true?

Also, I was wondering if there was an alternative to gels (something more natural)?

Context:
At DCM I took gels every 30mn from 1:30 on and still hit the wall from what I could gather.

Clearlier · 29-10-2014 5:46pm

Blue Steel wrote: »

I read that taking too many gels can also cause low blood sugar if you don't hydrate properly/enough because the gel is stuck in the stomach and doesn't go into the bloodstream.

Is this true?

Also, I was wondering if there was an alternative to gels (something more natural)?

Context:
At DCM I took gels every 30mn from 1:30 on and still hit the wall from what I could gather.

Lots of alternatives, try anything you like and see what works for you. Some commonly used ones are sweets such as jelly babies and wine gums, sports drinks and flapjacks.

Edit to add that hitting the wall while taking gels every 30 mins is either a sign that you were a bit depleted when you started the race or as I mentioned in a different post not trained properly to run a marathon. I don't know that you can expect to absorb much more calories than what you get from a gel although you could possibly be getting a high followed by a low which gels can do to some people in which case something less readily absorbed would be advised. Unfortunately you only find these things out by trial and error.

adrian522 · 29-10-2014 5:53pm

How many Gels would people normally go through in a marathon?

I went with one every 5 miles on Monday, seemed to work quite well. (didn't take one at 25, so 4 in all).

I've also heard people take 1 after an hour and then every 30 mins, which to me seems like a lot. (That would equate to 6 with my time from Monday).

Do people take gels and also take the sports drinks offered? I went with Gels but just took water on the course. As I said this seemed to work for me so probably a good idea not to change things too much, just interested in what others do.

T runner · 29-10-2014 6:11pm

Blue Steel wrote: »

I read that taking too many gels can also cause low blood sugar if you don't hydrate properly/enough because the gel is stuck in the stomach and doesn't go into the bloodstream.

Is this true?

Also, I was wondering if there was an alternative to gels (something more natural)?

Context:
At DCM I took gels every 30mn from 1:30 on and still hit the wall from what I could gather.

Gels will get sugar into your liver and thus into your blood i believe. They are of limited help and wont replace depleted glycogen in the legs.

If you hit the wall you may not have done enough long runs relevant to your marathon pace. Or you may have gone out too hard and ran out of juice early.

Sometimes if your long run pace was always significantly slower than your race day pace then unless those long runs were very very long you're in danger of hitting the wall.

Sometimes if you havent done enough running in preparation your legs will go. This isn't hitting the wall as such but it just means your legs didnt have enough muscular endurance.

jonny99 · 30-10-2014 1:05am

My experience: Ive only tried Gels once or twice,running many marathons without gels. Some of these have been difficult, and some a lot easier.
Everything to do with training, and nothing whatsoever to do with gels.Just my opinion.

Enduro · 30-10-2014 2:43pm

You don't need gels at all. They are useful for recovering if you do hit the wall (bonk), but its a better idea not to hit the wall in the first place. The Irish marathon record was set without taking any gels whatsoever. Clearly they're not required.

Blue Steel · 30-10-2014 4:14pm

Enduro wrote: »

You don't need gels at all. They are useful for recovering if you do hit the wall (bonk), but its a better idea not to hit the wall in the first place. The Irish marathon record was set without taking any gels whatsoever. Clearly they're not required.

This is precisely what I'd like to know.

Marathon records are set by people who run in less than 2:30 so they might not be good examples. Can someone who run it in 4h or even 5h do it without gels I wonder.

Clearlier · 30-10-2014 4:52pm

Blue Steel wrote: »

This is precisely what I'd like to know.

Marathon records are set by people who run in less than 2:30 so they might not be good examples. Can someone who run it in 4h or even 5h do it without gels I wonder.

Absolutely but you have to have trained for it and if you have trained for it to that point then you're likely to do it in less than 4 - 5 hours. Some ultra runners will run 4 - 5 hours without taking anything on board and travelling further than the marathon distance though.

martyboy48 · 30-10-2014 4:55pm

Blue Steel wrote: »

This is precisely what I'd like to know.

Marathon records are set by people who run in less than 2:30 so they might not be good examples. Can someone who run it in 4h or even 5h do it without gels I wonder.

Yes, I'm pretty sure they can. I never took gels and Ran DCM 13 in 3:53. My sister did DCM this year in 5:30 without gels, although she did have a few jellys...

jonny99 · 30-10-2014 5:11pm

Blue Steel wrote: »

This is precisely what I'd like to know.

Marathon records are set by people who run in less than 2:30 so they might not be good examples. Can someone who run it in 4h or even 5h do it without gels I wonder.

I reckon your question has been answered twice already.Trust me,Enduro knows what he's talking about, and although I havent a % of his talent, Ive enough marathons behind me to be sure of what I said above.Get the training and pre race diet right and save yourself the sticky fingers:)

Netwerk Errer · 30-10-2014 5:22pm

Blue Steel wrote: »

This is precisely what I'd like to know.

Marathon records are set by people who run in less than 2:30 so they might not be good examples. Can someone who run it in 4h or even 5h do it without gels I wonder.

Believe it or not. Overall time taken to run a marathon doesn't influence glycogen consumption. The very top elites only burn slightly less calories over the marathon than a 4 hour runner. The 2 hour glycogen rule is bogus. Top elites usually hit the wall well before two hours if they're running too fast. The trick to running a marathon without fuel problems is using glycogen sparingly.

The slower you run, the more fat will be used as fuel while glycogen use will drop. The faster you run, the more glycogen you will use compared to fat. This exact same rule applies to elites running 2.02 to someone running 4.30. It's not about time it takes you to run the distance, it's the distance and your personal pace that causes "hitting the wall".

Marathon training is all about teaching your body to burn an improved ratio of fat to glycogen at race pace. That's why long runs are essential and why a lot of runners run miles at marathon pace during training. They do it to be more efficient at race pace.

Enduro · 30-10-2014 5:44pm

Blue Steel wrote: »

This is precisely what I'd like to know.

Marathon records are set by people who run in less than 2:30 so they might not be good examples. Can someone who run it in 4h or even 5h do it without gels I wonder.

I'll give you a personal example from the other extreme then. I ran a 6 day race earlier this year (that's 6 continuous days of racing), clocking up over 800km in that time. I didn't use any gels. In fact they would have been counterproductive in my opinion. I was fat-burning all the way, so had no worries about needing to replinish sugars. In fact I ate hardly anything for most of the race, far far less than I would normally eat in the same timeframe if I wasn't racing!

If you're running for 4-5 hours you should be running in the fat-burn zone. Gels will only disrupt your fat burning "engine".

The key to this, as others have said, is to have put in the right training. AS well as putting in all the miles, and all the quality sessions, that can also be extended to include a focus on training your body to be a more efficient fat-burning machine.

Gels are not a magic food. They are definitely not necessary. In a few extreme emergency cases they can be useful, but even then only after something more fundamental has gone wrong.

Netwerk Errer · 30-10-2014 6:07pm

Enduro wrote: »

If you're running for 4-5 hours you should be running in the fat-burn zone. Gels will only disrupt your fat burning "engine"..

I agree completely with everything else you have said but not this point.

Running a marathon is always a glycogen dominant fuel distance. The ratio of glycogen to fat is around 70/30 when running at your aerobic threshold(actual marathon ability, not marathon goal pace). You don't need gels if you run at this pace or slower. The thing is that we are all amateurs and don't have a very good idea of our AT capabilities. It's easy for us to make pace misjudgements and push that ratio higher than 70% consumption of glycogen.

Gels will help if that misjudgement is small and that's about it. If you go out a lot faster than your AT, you're in trouble no matter how much fuel you take in. That's the reason I take gels. They are a safeguard against slight pace mistakes I may make during a marathon.

Blue Steel · 30-10-2014 6:13pm

Thanks for that. Very helpful!

Another reason why I naively took gels on Monday was that I was afraid of the hunger I normally get at around 11:15am as I normally have lunch around that time.

btw I agree my training was below Marathon requirements, in fact I knew that before I go into the race but I assumed my regular training + willpower would do the trick (I was wrong).

Enduro wrote: »

I'll give you a personal example from the other extreme then. I ran a 6 day race earlier this year (that's 6 continuous days of racing), clocking up over 800km in that time. I didn't use any gels. In fact they would have been counterproductive in my opinion. I was fat-burning all the way, so had no worries about needing to replinish sugars. In fact I ate hardly anything for most of the race, far far less than I would normally eat in the same timeframe if I wasn't racing!

If you're running for 4-5 hours you should be running in the fat-burn zone. Gels will only disrupt your fat burning "engine".

The key to this, as others have said, is to have put in the right training. AS well as putting in all the miles, and all the quality sessions, that can also be extended to include a focus on training your body to be a more efficient fat-burning machine.

Gels are not a magic food. They are definitely not necessary. In a few extreme emergency cases they can be useful, but even then only after something more fundamental has gone wrong.

Netwerk Errer · 30-10-2014 6:58pm

This might help explain the process better. 2.16 marathon runner Sage Canaday.

http://m.youtube.com/watch?v=6AOJvV27HOU

inigo · 04-11-2014 9:56pm

Enduro wrote: »

I was fat-burning all the way, so had no worries about needing to replinish sugars. In fact I ate hardly anything for most of the race, far far less than I would normally eat in the same timeframe if I wasn't racing!

If you're running for 4-5 hours you should be running in the fat-burn zone. Gels will only disrupt your fat burning "engine".

The key to this, as others have said, is to have put in the right training. AS well as putting in all the miles, and all the quality sessions, that can also be extended to include a focus on training your body to be a more efficient fat-burning machine.

This is something I would really like to achieve to some extent at some point in time.

But what are the "right training" and the "quality sessions"? I've done a bit of reading and training by heart rate seems to be the way to go. Only problem is that there are quite a few different ways of defining the fat burning zone (% ranges), and some of them differ greatly. Would the "enduros" here please mind giving beginners like me some pointers as to how they manage to become such fat burning machines? Perhaps even some links or references?

viperlogic · 04-11-2014 10:16pm

Only true way to find your zones is a VO2max test. There are a few places that perform this test around the country. This test is approx €100. It will also find your max HR.

Otherwise you can do your own test with a HRM and by finding a hill and running up it about three times to find your max HR. Have a google on how exactly to do this test. Another is to do a 5K race flat out. Paces/zones can be some what worked out from that result. Again, not exact but not far off.

Me personally, I don't use gels anymore during LSR's or marathons and ran a 2:58 marathon 2 weeks ago. (well I did have one but that was for the caffeine)

inigo · 04-11-2014 10:23pm

Blue Steel wrote: »

Also, I was wondering if there was an alternative to gels (something more natural)?

I managed my long runs and marathon wiht a combination of big meaty dates stuffed with peanut or almond butter and home made sushi rolls stuffed with roasted & salted peanuts :cool:, one of each at half hour intervals. Cheaper than gels. Yummy combination of sweet and savoury with simple and complex carbs, fat, salt and other electrolytes. Only problem was the chewing...:D

inigo · 04-11-2014 10:29pm

viperlogic wrote: »

Otherwise you can do your own test with a HRM and by finding a hill and running up it about three times to find your max HR. Have a google on how exactly to do this test. Another is to do a 5K race flat out. Paces/zones can be some what worked out from that result. Again, not exact but not far off.

Which %s would you use then to define your zones?

viperlogic · 04-11-2014 10:41pm

inigo wrote: »

Which %s would you use then to define your zones?

I use the P&D paces...
Recovery <76%
General Aerobic 70-81%
Long/Medium long 74-84%
Marathon pace 79-88%
Lactate threshold 82-91%
VO2max 93-95%

Again you need to find your max HR doing lab or hill test and not do 220 -age calc

Enduro · 05-11-2014 12:52pm

inigo wrote: »

This is something I would really like to achieve to some extent at some point in time.

But what are the "right training" and the "quality sessions"? I've done a bit of reading and training by heart rate seems to be the way to go. Only problem is that there are quite a few different ways of defining the fat burning zone (% ranges), and some of them differ greatly. Would the "enduros" here please mind giving beginners like me some pointers as to how they manage to become such fat burning machines? Perhaps even some links or references?

Just to add a little on training to develop your fat burning "engine". There are a couple of things you can do, some easier than others. Changing to more healthy diet is an obvious startpoint. There are a lot of differing opinions on what exactly that means. But there are a few things that the vast majority of people would agree on. The most important of these would be to ditch processed foods and east natural foods. So any food which doesn't have a list of ingrediants is generally good... natural food is the ingrediant! Vegtables, fish, meat, fruits (but not too much, and not juices), preferably fresh and home cooked/prepared. Personally, I try to cut down on carbs as much as possible as well.

Eliminate sugar from your diet as much as possible. Cut out as much junk as you can. Gels are very definitely in the junk category here.

Do all your long runs on empty. So don't eat before you head out on a run, and don't eat during the run (No sugary drinks either). This is particularly effective for morning runs, as there should be a long gap since your last food intake. If you find this difficult that's OK. Training is putting your body under stress so that it can adapt. Same here!

Blue Steel · 05-11-2014 2:30pm

viperlogic wrote: »

Only true way to find your zones is a VO2max test. There are a few places that perform this test around the country. This test is approx €100. It will also find your max HR.

Otherwise you can do your own test with a HRM and by finding a hill and running up it about three times to find your max HR. Have a google on how exactly to do this test. Another is to do a 5K race flat out. Paces/zones can be some what worked out from that result. Again, not exact but not far off.

Me personally, I don't use gels anymore during LSR's or marathons and ran a 2:58 marathon 2 weeks ago. (well I did have one but that was for the caffeine)

Can anyone recommend a test centre?

Google found UCD laboratory for me.

viperlogic · 05-11-2014 2:36pm

Blue Steel wrote: »

Can anyone recommend a test centre?

Google found UCD laboratory for me.

If down near Cork then I would recommend Trevor Woods in UCC. His Human Performance Lab is located in the Mardyke Arena complex.

Blue Steel · 05-11-2014 2:36pm

I'm thinking of doing the below found on the net. If anyone think it is no good please let me know.

I have a Garmin 620 with HRM (will it be accurate?)

-- start quote --
1. Be sure you're well rested, well hydrated, and well warmed up.

2. Run hard and fast for 2 to 3 minutes. Jog back to your starting point. Repeat two more times, running a little harder and faster each time. On the third and last repeat, pretend you're running an Olympic race.

3. Check your heart rate during and immediately after the last repeat. The highest number you see is your maximum heart rate (MHR).
-- end quote --

viperlogic · 05-11-2014 2:43pm

Blue Steel wrote: »

I have a Garmin 620 with HRM (will it be accurate?)

Should be, never had issues with mine. Just make sure pads are moist and your top is slightly damp/wet in one area to avoid any possible static issues that can result in spikes. If you have done a good warm up and sweating then shouldn't be an issue. No need to monitor the watch for max HR while running, you can do that afterwards on the watch or Garmin Connect or Strava etc

viperlogic · 05-11-2014 2:49pm

Blue Steel wrote: »

I'm thinking of doing the below found on the net. If anyone think it is no good please let me know.

Some say to do it on a slight incline but not steep enough that your legs give up before your heart does

TFBubendorfer · 05-11-2014 3:19pm

Blue Steel wrote: »

I'm thinking of doing the below found on the net. If anyone think it is no good please let me know.

Sounds familiar. I think I read that nearly 10 years ago when trying to find a way to measure my own max HR.

To be honest I'd be surprised if anyone would manage to get their HR up to their max in so short a time. 3rd repeat of 2-3 mins?

I got my highest ever HR reading at the end of a 5k race with an uphill finish when I was chasing another runner. Was absolutely destroyed afterwards. Come what may, I never managed to run anywhere near as hard in training, no matter how hard I tried.

Then again, try that regime and then add a few beats on top of that and you might get reasonably close to your true HR max. Alternatively, running up a hill very hard a few times might get you a similar reading.

kit3 · 05-11-2014 3:34pm

Enduro wrote: »

Just to add a little on training to develop your fat burning "engine". There are a couple of things you can do, some easier than others. Changing to more healthy diet is an obvious startpoint. There are a lot of differing opinions on what exactly that means. But there are a few things that the vast majority of people would agree on. The most important of these would be to ditch processed foods and east natural foods. So any food which doesn't have a list of ingrediants is generally good... natural food is the ingrediant! Vegtables, fish, meat, fruits (but not too much, and not juices), preferably fresh and home cooked/prepared. Personally, I try to cut down on carbs as much as possible as well.

Eliminate sugar from your diet as much as possible. Cut out as much junk as you can. Gels are very definitely in the junk category here.

Do all your long runs on empty. So don't eat before you head out on a run, and don't eat during the run (No sugary drinks either). This is particularly effective for morning runs, as there should be a long gap since your last food intake. If you find this difficult that's OK. Training is putting your body under stress so that it can adapt. Same here!

Any particular reason why you cut down on carbs ? Also, when you do your long runs on empty how much liquid would you take on & do you take any electrolytes ?

pistol_75 · 05-11-2014 4:11pm

kit3 wrote: »

Any particular reason why you cut down on carbs ? Also, when you do your long runs on empty how much liquid would you take on & do you take any electrolytes ?

Here's my take on it:

1g of Carbs provides around 4 Kcals of energy
1g of Fat provides around 9 Kcals of energy

No matter how much Carbs you eat your body can only store a certain amount of Glycogen. Even on people with very low body fat % there is enough fat to fuel for an awful lot longer.

Your body will look to tap into your glycogen stores first as the easiest source of energy and if you run out, you will bonk or hit the wall as they say which tends to come around the 20 mile mark. This is just your body running out of energy.

If you can train your body to use Fat as an energy source, obviously you will have enough energy to keep going for longer. The higher the % of Fat being burned then the lower the reliance on Glycogen.

You will hear stories of guys running for hours on empty and it having no impact on them, but it is important to note this is something they have built up to over time. They weren't able to just go out and run for 4 hours with no fuel.

To train your body to burn fat as a fuel source, this is normally done where people are running at a lower intensity and it builds up over time, for example someone doing their long runs each week on empty and progressing over time. This will teach the body to switch on to Fat as a source of fuel over time.

Personally I can see the benefits to this, but then you have to factor in that on race day you will be asking your body to perform at a different intensity to your training runs so it will still rely on Glycogen as a form of energy. The difference now though is because you have increased the % of fuel being burned as Fat your body will still be able to perform for longer before the energy runs out. It should also lead to less of a reliance on gels, BUT most people definitely will need to be topping up their sugar levels during a marathon run at a high intensity for them.

If you are going to start doing some training runs on empty at least ensure you take a drink of water before you go out to run. Your kidneys will have been working while you were asleep and most of us wake up in a slightly dehydrated state anyway due to this. It doesn't make sense to be starting your run off slightly dehydrated.

ThePiedPiper · 05-11-2014 4:27pm

I would accept everything Enduro says, but in my own experience, it didn't quite work to perfection for me. There were a few other factors at play, but for my first ten marathons, I only negative split in my 2nd, and was often positive splitting to the tune of 15 minutes. I was clearly running out of gas. Gels would have helped me in those situations, but training was also at fault.

These days, I try and do maybe half my long runs on empty, and totally acknowledge and recognise the value in that. However, I would still use up to 5 gels in a marathon, as I don't go beyond 23 miles in training and the pace of the 23 mile long run is 1:00 min/mile slower than race pace. In my situation where I rarely run over 70 mpw, I think gels (or any source of energy) is nearly essential in race. But, it's only one if a whole package of measures, including 20 milers on empty, that have improved my times substantially.

kit3 · 05-11-2014 4:32pm

That makes sense - I've done a lot of long runs on empty (a lot of the time more down to not being organised than anything else

) but I've used gels in the 3 marathons I've done. I suspect in some ways that they are an emotional crutch to some degree but it works for me .................

Marathon - glycogen management while running

Comments