the wall

ntlbell

i was reading about "the wall" on runners world and still can't really grasp what it is i thought a wall would be a mental block on where you couldn't get past a specific time or finish a specific distance

would anyone mind explaining exactly what it is and how to avoid it?

Stark

In terms of marathons, it's when the body's glycogen store runs out and you fall back to burning fat.

Running Bing

ntlbell wrote: »

i was reading about "the wall" on runners world and still can't really grasp what it is i thought a wall would be a mental block on where you couldn't get past a specific time or finish a specific distance

would anyone mind explaining exactly what it is and how to avoid it?

The classic definition I always see is that it is the point where glycogen stores in the muscles run out and you have to rely solely on burning fat as the energy source to keep you going. The body is not as efficient at burning fat for energy and so the activity becomes much harder and more of a struggle.


You can only store a certain amount of Glycogen in the muscles and this is usually only enough to power you to the 18-20mile mark in the marathon for a lot of people.

The thing I never understand is why do you still hit the wall even if you take on Carbs during a race? For instance I did an 18 miler today. I drank Lucozade Sport during the run and took a carbo gel at around the 10 mile mark....come the last couple of miles I was absolutely beat, I was working extremely hard to keep going and I certainly felt like I was hitting the wall. I must point out that is the farthest I have ever gone so maybe its natural for the body to revolt a bit?

donothoponpop

The Wall occurs when your body runs out of its glycogen (stored carbohydrates) which it has been converting to energy, and switches to burning fat, which is less efficient and forces you to slow down/cramp up/sell your firstborn for the race to end. The average fit runner has enough glycogen to get to 17 miles or so. The more marathon specific training you do (specifically long runs), the more your body adapts to creating larger glycogen stores in muscles and liver. This means you can run harder, longer, until the Wall sets in (if indeed it does). Cramming the body full of glycogen is why marathoners carbo load with pasta in the days before the race.

In my first marathon, I never hit the Wall, as I was running too easy. My second, I hit the Wall big time around 19 miles, and died the last 7, as I ran too hard for the training I had been doing, and had not done enough long runs. This marathon, I hope to be hitting the bend for home before I become glycogen depleted.

Hope this helps, good luck.

Krusty_Clown

donothoponpop wrote: »

which is less efficient and forces you to slow down/cramp up/sell your firstborn for the race to end

ntlbell

Ok, that makes sense

but like someone else mentioned if you take on carbs after say 8-10miles will they be used nearing the end of the race or does it take too long for the carb to be stored then used?

From reading runners world it sounded like you start losing your mind hallucinating etc etc

Krusty_Clown

I believe that the gels start working after 15 minutes, and sports drinks are around the same. They're isotonic, which means they have approximately the same salt concentration as blood, and as such are absorbed very quickly.

CatFromHue

There is alot of good scientific explanations of the wall but for me it was were my attitude changed from "Yeah i can do this thing" to "this is stupid, if i walk ill still get there AND it'll be easier".
As ive only ran one marathon i cant really say how to avoid it, but dont let it stop you.
need less to say i didnt stop running to walk! i feel much the better for it now (5 months on)

tunney

donothoponpop wrote: »

The more marathon specific training you do (specifically long runs), the more your body adapts to creating larger glycogen stores in muscles and liver. This means you can run harder, longer, until the Wall sets in (if indeed it does).

As far as I know this is incorrect.

The purpose of marathon specific training is to train the body to become more efficient at burning fat as a fuel. The more fat you use the longer your glycogen stores last.

tunney

ntlbell wrote: »

Ok, that makes sense

but like someone else mentioned if you take on carbs after say 8-10miles will they be used nearing the end of the race or does it take too long for the carb to be stored then used?

From reading runners world it sounded like you start losing your mind hallucinating etc etc

There is a maximum number of calories that the body can absorb per hour. Its not a huge amount either.

donothoponpop

tunney wrote: »

As far as I know this is incorrect.

The purpose of marathon specific training is to train the body to become more efficient at burning fat as a fuel. The more fat you use the longer your glycogen stores last.

Everything I have read suggests the body burns *primarily* glycogen first, until stores run low, and the body then starts to burn the less efficient fat. Specifically, in "advanced Marathoning" by P&D, they talk of the long runs as helping to increase the amount of glycogen the body can store, on muscles and in the liver- admititly while simultaneously making the body more efficient at burning fat.

Either way, doing at least three 20+ miles in training at a reasonable pace will help the body stave off glycogen depletion, which causes "the Wall".

hunnymonster

dono, my understanding is similar to Tunney's, in that there is a huge intensity effect. Keep your HR low enough and you can supply your body with enough carbs to replace glycogen at the rate you are using it (or very close to). Otherwise it would be hard to explain how anyone can do ultra distances. Training, while improving glocogen sparing also trains the body to work off fat for longer at the same (or increasing) intensities. Sorry if I've not explained this very well. Head still addled from the URTI I've had for last 10 days.

hunnymonster

tunney wrote: »

There is a maximum number of calories that the body can absorb per hour. Its not a huge amount either.

generally 200-400 depending on a person's size and body composition. This is while exercising (blood working all around the body) at rest it could be more (blood can be dedicated to digestion)

tunney

donothoponpop wrote: »

Everything I have read suggests the body burns glycogen first, until stores run low, and the body then starts to burn the less efficient fat. Specifically, in "advanced Marathoning" by P&D, they talk of the long runs as helping to increase the amount of glycogen the body can store, on muscles and in the liver- admititly while simultaneously making the body more efficient at burning fat.

Either way, doing at least three 20+ miles in training at a reasonable pace will help the body stave off glycogen depletion, which causes "the Wall".

I wonder what you have been reading

The body never burns exclusively either fat or glycogen. It burns both. At low intensities the majority of the energy comes from fat. As the intensity raises the proportion of glycogen to fat used to supply the required energy increases.

The "wall" occurs when the glycogen stores are completed and the athlete must drop back to the intensity at which they are primarily burning fat as fuel.

Endurance training for marathons aims at increasing the intensity at which fat is the primary source of fuel. This means that the ratio of fat:glycogen burned will higher and those precious glycogen stores can be made to last longer. Fuel efficency and fat burning are what the marathon and longer distance events are all about.

If you are going to read and quote any books probably the best one to use is "Lore of Running" by Tim Noakes. Well worth a purchase.

Stark

ntlbell wrote: »

From reading runners world it sounded like you start losing your mind hallucinating etc etc

Well the brain is a demanding consumer of glycogen. Once the supplies are close to gone, you'll start to suffer impaired brain function.

cfitz

Stark wrote: »

Well the brain is a demanding consumer of glycogen.

That's interesting. I'm not very well up on this area. How controllable is this brain usage?! Does anyone know any studies that show significant improvement in performance by conserving glycogen usage by the brain?

tunney

cfitz wrote: »

That's interesting. I'm not very well up on this area. How controllable is this brain usage?! Does anyone know any studies that show significant improvement in performance by conserving glycogen usage by the brain?

As far as I know its not that controllable, sure nervous energy etc etc might be controlled and that might have an impact but I doubt it.

I'm not aware of any studies into controlling brain glycogen usage, I think its pretty much a fixed factor.

cfitz

tunney wrote: »

As far as I know its not that controllable, sure nervous energy etc etc might be controlled and that might have an impact but I doubt it.

I'm not aware of any studies into controlling brain glycogen usage, I think its pretty much a fixed factor.

Thanks. Was wondering if anyone had measured the possible benefits of staying very relaxed mentally while running long distances.

donothoponpop

tunney wrote: »

I wonder what you have been reading

The body never burns exclusively either fat or glycogen. It burns both.

Sorry Tunney, my post was unclear. I agree with this, and my post above should have said "primarily" burns glycogen, and then moves to fat as its primary fuel source. Racing the marathon will mean you will use about 75-90% of your fuel from carbs, until they run low. Jogging the marathon will mean you will use a lower proportion of carbs.

tunney wrote: »

If you are going to read and quote any books probably the best one to use is "Lore of Running" by Tim Noakes. Well worth a purchase.

I have been told its a runners bible. Definately one for the library.

hunnymonster

I just did a quick look through the neurology literature and the only stuff related to brain glycogen metabolism I could find was related to brain injury. sorry. There were a couple of exercise physiologists on here a while ago, if they turn up again, we must suggest a new phd topic for them :-)

MCOS

ntlbell wrote: »

i was reading about "the wall" on runners world and still can't really grasp what it is i thought a wall would be a mental block on where you couldn't get past a specific time or finish a specific distance

would anyone mind explaining exactly what it is and how to avoid it?

Hi, lots to chew on from the guys above on what it is. Simple rules really to keep the wall at bay

1. Do your long runs as planned in training
2. Drink before you are thirsty on your long runs
3. Eat (or take gels etc..) before you are hungry on your long runs
4. Start the marathon fresh, fed, hydrated and healthy
5. Stick to your plan, don't do anything too different on the day.

I hit the wall yesterday on a bike ride. It was almost the same as hitting it on a run, within 5 minutes I went from feeling good to being dizzy and unable to climb a short hill. I was starving... struggled home and put away 3 banana sandwiches, 2 cereal bars, a 500ml breakfast drink, a pint of orange juice, a full roast dinner all within a hour. My own fault, I planned to go out for a short ride before dinner and ended up doing 60k.

tunney

I don't think that was the wall you hit MCOS, I think 60km is too short to hit the wall.

MCOS

tunney wrote: »

I don't think that was the wall you hit MCOS, I think 60km is too short to hit the wall.

Fair enough. It sure felt like it though. I started running about 15 months ago and first hit a wall at around the 2 hours mark. I felt the same yesterday after 100mins. Depleted is a word.


Yesterday was only my 3rd spin on a road bike and last cycled to and from college on my MTB years ago. After about 56k I barely had the power in my legs to get over the last 2 hills home. It may a have been a short bike ride (even though it was my longest ever) but I did do 21miles for my long run on saturday morning so that probably had more to do with it! Yesterday was my rest day but I got carried away and didn't exactly take it easy...

Wally Runs

It has been my understanding (must find the source) that it is your brain that hits the wall first and then your body. That is to say before you run completely flat out of glycogen, your brain being a large user of energy starts to shut down the body to conserve the remaining glycogen sourced energy for itself.

This being the case you can 'mentally' tell your body that there is glycogen energy in reserve and over ride your brain. (Yeah I know! imagine fooling yourself) It is part of that internalising or externalising thing. I have used it once to push through the wall, but it only worked for a short while.

That said, I also read that men are more likely to hit the wall then women because they expect too. It appears that women think much more positively while running and men less so. The moral being if you expect to hit the wall you probably will!

hunnymonster

I don't think it's a mental thing between men and women. Women do have higher body fat so that might be a factor. If we have a higher pain threshold or not appears to depend on who did the research, in any case it's a small effect. Women may also be more sensible with pacing?

Stark

I googled about female ultrarunners (a sport in which some say women can perform comparatively to if not better than men) and found this:

http://www.lehigh.edu/~dmd1/amy.html

Not very conclusive, but it does seem to rule out the body fat theory and suggests sensible pacing as the most likely reason. Some interesting bits in there.

cfitz

Stark wrote: »

I googled about female ultrarunners (a sport in which some say women can perform comparatively to if not better than men) and found this:

http://www.lehigh.edu/~dmd1/amy.html

Not very conclusive, but it does seem to rule out the body fat theory and suggests sensible pacing as the most likely reason. Some interesting bits in there.

Eh, that looks fairly conclusive to me - the best men are significantly better than the best women.

Racing Flat

ntlbell wrote: »

i was reading about "the wall" on runners world and still can't really grasp what it is i thought a wall would be a mental block on where you couldn't get past a specific time or finish a specific distance

would anyone mind explaining exactly what it is and how to avoid it?

As opthers have said, it's where glycogen more or less gets used up and then you rely more on fat as an energy source. If you have not trained your body to use fat as an energy source and if youer body isn't naturally very good at doing this you might hit a wall whereby you slow significantly, feel like you've no energy and it may affect coordination and things as it progresses. You can train your body to get used to using fat as an energy source by asking it to do so - ie doing long runs. Anything over around 17miles should do the trick.

So if you have the long runs done and you fuel well beforehand you should not really be too affected by the wall. I would not expect to hit a wall when running a marathon as long as I don't go out too fast. Just may slow a little in last few miles (a minute a mile max) but that would be more down to normal end of race fatigue than the wall.

The wall is for people who don't train or go off too fast.

Racing Flat

cfitz wrote: »

Thanks. Was wondering if anyone had measured the possible benefits of staying very relaxed mentally while running long distances.

I don't think staying relaxed mentally would have any effects on brain glycogen. I imagine glycogen stores would be affected systemically rather than locally.

But staying relaxed mentally may well improve running form and so less energy would be used by the entire body for a given pace and so you would perform better. A coach Dave Welch (Patricia Welch's. (2.26 for marathon as Master) husband and coach) gets his athlete to go onto a treadmill at a fixed (comfortable) pace. He then waits until their heart rate is steady at that pace. Then he'll ask them to relax and see if the heart rate goes down. He'll then instruct them to drop the shoulders, take a shorter stride, keep the head up, move the arms more efficiently, one by one, each time seeing what effect it has on heart rate. When they find the running 'style' that equates to the lowest heart rate for the given pace, the runner tries to replicate this in training. He advocates that this leads to improved economy and so better performance. Sounds reasonable to me. Could be done fairly similarly on a track or with a GPS I suppose.

ekevosu

an extreme example of the wall

https://www.youtube.com/watch?v=MTn1v5TGK_w

hunnymonster

cfitz wrote: »

Eh, that looks fairly conclusive to me - the best men are significantly better than the best women.

depends on the event. I still think no matter what the distance, men are going to slightly have it but "significantly" better is pushing it a bit in many utra-races. Have a look at the Dean Karnazes/Pam Reed spat.


That said, I don't expect to compete with the best men so I guess I;m in overall agreement with you cfitz. I may not win the overall race in ultramarathons (though I have won the women's event in the last 3 I've done) but I always place much higher up the rankings overall than I would in a marathon or other shorter race. The same is true for the other leading and even midpack women. We may not be as fast as the fastest men, but we're also not as slow as the slowest men :-)

hunnymonster

ekevosu wrote: »

an extreme example of the wall

It's horrendous to watch isn't it. The Julie Moss one mentioned in the clip is in a similar vein. For new runners, those women were coming to the end of an ironman triathlon (3.8 swim, 140 bike and then the 42.2 run). They are also racing in Kona where the heat and humidity are very very tough. Unless you're doing something very wrong, that is very unlikely to happen to you at the Dublin marathon.

cfitz

hunnymonster wrote: »

depends on the event. I still think no matter what the distance, men are going to slightly have it but "significantly" better is pushing it a bit in many utra-races.

Well I was going by the figures in the article. It said that, generally, the fastest man is 9 - 11 percent quicker over the distance. So that's the equivalent of upwards of 12 minutes for a marathon. I'd consider 12 minutes significant in a marathon.

hunnymonster wrote: »

That said, I don't expect to compete with the best men so I guess I;m in overall agreement with you cfitz. I may not win the overall race in ultramarathons (though I have won the women's event in the last 3 I've done) but I always place much higher up the rankings overall than I would in a marathon or other shorter race.

So the gap may be shorter as the distance increases or perhaps there are other factors. With regard to the future we can engage in all sorts of speculation about more women in sport etc. But really that is just speculation. The current status seems to be that men are better than women over all distances in running.

hunnymonster wrote: »

The same is true for the other leading and even midpack women. We may not be as fast as the fastest men, but we're also not as slow as the slowest men :-)

In an Ultra race would the average finishing time for the ladies usually be faster than the average finishing time for the men? (as in sum of male finishing times divided by number of male competitors...)