Wk7 – 20.1M marathon training & Hitting the Wall

Saturday morning and I wasn’t looking forward to what the weather was meant to be bringing.  Cold (1’C) rain from the West and snow… :-/  And we got it all.  I wrapped up warm as I knew we’d be out for about 3 – 3:30 hours.  Nike warm top, t-shirt, asics long sleeved top and my high viz waterproof jacket.   Buff for my ears and knee length shorts.  And I’m glad I wore all that!

I was warm at the start but once we got about 8 miles in onto the Clyde and Forth Canal the wind was against us and the rain…and snow came down a plenty.

Before the run I had a bowl of porridge and a caffeine lucozade, then I took an energy gel at about an hour and 10 minutes, and then again at about 2 hours and 5. But I think it would be good to take them sooner to get the effect of them.  I had my garmin covered up and I wasn’t really paying attention to time or distance.

The route I chose was good.  From Bella, across the Clyde at the BBC, through Whiteinch, Yoker, up the cycle path to Clydebank (8 miles in)…then along the Forth & Clyde canal….we seemed to be a bit higher up and the weather took a turn for the worst….hard work.  It was also slightly uphill which I didn’t really realise… then down following the Kelvin river into town and back to the BBC and Bella a different way.

I didn’t know the route down by the Kelvin but it was actually the nicest part of the run. We stopped a few times to take gels, and at one point at Lock 27 I wasn’t sure if we should keep going or stop…but we kept going and got to where we needed to be.

About 17 miles in I noticed Julie Ann get a bit quiet… she was stuggling a bit I think because of over doing exercise last week and not taking enough gels / energy before and during the run.  It’s good that it happened today too so that she can plan ahead for the actual marathon and make sure she energises and drinks enough on the day to get her thorugh.

She started to feel like she couldn’t go on…. felt sick, dizzy and burpy.  Her legs were ok but her mind was telling her to stop / walk.  We stopped at the top of a hill about a mile from Bella, then we walked through some of Bella park.  I didn’t mind as it was more important for her to feel ok rather than push herself and feel worse.

I’d read about what was happening and I knew she should take it easy.  We were less than a mile from finishing and I didn’t mind if we walked the whole rest of the way back. I think it happened to me once on a 22 mile run and it was not nice….

Here’s what happened (taken from page 244 of the Competitive Runners Handbook by Bob Glover):

Hitting the wall

Hitting the wall means running very low on glycogen, the carbs stored in your running muscles.  After about 90 minutes of running, you begin to deplete.  The longer you run, the more you deplete.  If you deplete too much, you’ll be engulfed by fatigue.  For most runners, that will be somewhere between the 10 miles and the halfway mark  Most trained runners can store about 18 – 20 miles worth of carbs.  That’s why this distance is known as the theoretical location of the wall.  But some runners may deplete glycogen reserves a few miles sooner, some a few miles later.

Here’s what happens.  When the muscles start to run low on glycogen, a chain reaction takes place.  Your body attempts to conserve what glycogen you have remaining by burning more fat for energy.  As less and less glycogen is available to help you keep going, fat becomes the primary fuel.  The result: You have to slow down to provide extra oxygen to metabolise fat.  Glycogen stored in the liver also depletes, causing a shortage of blood sugar which is needed to feed the brain.  As a result, mental fatigue sets in.  You feel lightheaded, unco-ordinated confused, depressed, unmotivated.  Now you not only can’t run faster, you don’t care.

How do you beat the wall?

Here’s how:  Train your muscles. High mileage and long training runs cause muscle cells to adapt to store more glycogen. According to a study, well trained muscles store 20 – 50% more glycogen than untrained muscles.  Long runs develop mitochondria in cells to metabolise oxygen so that fat can be used more efficiently as fuel.  This ‘spares’ some of the glycogen for later use.  If you only burned glycogen you would run low and ‘Hit the Wall’ much earlier and much harder.  By conserving glycogen and utilising some fat, you’ll have sufficient energy reserves to keep a good pace in the late stages of a marathon.  It’s during this transition from glycogen to fat for fuel that much of the discomfort associated with the Wall takes place.  The more glycogen depletion runs you do, the better trained your muscles become to make this transition.

Taper and carbo load. Cutting back training as the marathon gets close, means you’ll be burning off less muscle glycogen.  Resting the muscles allows them to store more carbs for the marathon effort.  In conjunction with tapering, fueling with carbo loading programme will saturate your muscles with glycogen and help power you past the Wall.  This includes carbs consumed in the days leading up to the race, on race morning, and on the run.  Here’s where the high tech sports drinks, energy gels and bars can help you out.

Don’t start too fast. Starting too fast will burn off more glycogen prematurely.   A conservative starting pace helps save glycogen for later in the marathon, pushing back the Wall and lessening the sensation of stress when you do hit it.

Fight dehydration. As you dehydrate, heart rate increases even if you don’t increase the pace.  As you work harder to keep the pace, you burn off more glycogen more rapidly.  Drinking plenty of fluids before and during the race (ideally a sports drink with carbs) will minimise dehydration.

Train your mind.  You will run short of glycogen at some point in the marathon.  The question is when and how badly you ‘Hit the Wall’ and how well you cope with it mentally.  You will hit bad patches in the race as your body adapts to burning fat for fuel.  How tough will it get? You never know until it happens.  If you’ve prepared for it properly, it most likely will just be a few miles of discomfort.

If you train, hydrate and fuel well before, during and after the marathon and you might not hit the Wall.  Stay positive and have good mental thoughts to get you through the Wall and the marathon.

I’ll have a set plan in place… I think 4 energy gels over the course of the marathon… (50 mins, 1:30, 2:10, 2:50), will have hopefully sorted a carb load strategy for the few days before the marathon and will hydrate properly too.  Fingers crossed I don’t hit the Wall!

We managed to finish in 3 hours 19 and I had enjoyed the run, the route and the chat… pity about the weather (and the Wall)… but perhaps it will make us stronger for the marathon?!

Run: 20.1M, 3:19, Pace: 9:30, Calories: 2,065
Ave HR: 138 (73%), Max: 159 (84%)

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1 Response to Wk7 – 20.1M marathon training & Hitting the Wall

  1. Pingback: Exercising whilst fasted | Lorn Pearson Trains…

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