Running on an empty stomach and not taking gels/nutrition during runs

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Feb 2015
9:47pm, 14 Feb 2015
1,306 posts
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I too do not consume fuel in runs less than 3 hours duration unless I am testing marathon fuelling strategy. I sometimes start in a fasted state, but it is necessary to be a bit careful about this.

The evidence on the benefits of training in a fasted state is inconsistent. Most studies show improved capacity to burn fat but the effects on race performance are mixed. It is certainly beneficial for distance runners, especially marathoners and ultra-marathoners to improve fat burning capacity, but the overall net benefit depends on how much you stress your body by training when fasted. If you do not already have well developed capacity to burn fat you will consume glycogen quite rapidly. The rate of glycogen consumption increases markedly with increasing pace. Once glycogen stores are appreciably depleted, there will be an increase in stress hormones as a response to ensure the brain is not deprived of glucose. Sustained increase in stress hormones can undermine the benefits of training.

So the two practical conclusions are that you should build up your capacity to run long distances without refuelling, gradually. Secondly, the rate at which you are running out of glycogen is greater at faster paces. You can usually tell when you are starting to run out of glycogen by a sharp increase in fatigue. If you experience this during training runs, you are beginning to place appreciable stress on the body. Do not do this often
Feb 2015
10:11pm, 14 Feb 2015
4,327 posts
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Great comments, Canute.

One thing I would add, from a very personal point of view, is that aside from really bonking during my first marathon in 2008 I have never run out of energy. But what restricts performance is fatigue. On races (marathons) when I've finished strongly it has always been when the fatigue has been minimal. Fatigue represents itself as lack of range of movement. I've got the energy to run faster but have been unable to put that power down.
Feb 2015
10:35pm, 14 Feb 2015
1,443 posts
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I used to bonk at 7 miles (early days of running) but can now happily skip along for 2-2.5 hours on just a cuppa tea. It takes practice though and if I start pace pushing I do suffer a bit. Main difference to me is that I can feel totally wiped for the rest of the day
Feb 2015
10:37pm, 14 Feb 2015
4,330 posts
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Perhaps I'm used to it, but up to 20 miles I'm still good to go for the rest of the day after a something to eat and drink plus a bath!
Feb 2015
11:24am, 15 Feb 2015
4,338 posts
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Ran my fastest HM on no fuel or drink before or during today.
Feb 2015
6:34pm, 22 Feb 2015
36 posts
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Did 17 miles on just a glass of orange before I left the house, plus 3 bites of a clif bar after 10miles. And water. Had a decent pasta meal ( and half a bottle of red) last night at about 10 pm, so not hungry when I got up this am.
It was cold day, but I've ran in much colder weather- I did feel a bit sleepy near the end ( usual sign of needing food), but more importantly, Iwas freezing cold from about 5 miles- both arms went steadily numb, and I struggled to warm up despite wearing an extra jacket, which is usually far too hot to run in- do you think the inability to get warm was related to the lack of food?
Feb 2015
12:11pm, 25 Feb 2015
24 posts
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I have ran two marathons and have another planned for April. I have never used gels up to half marathon, however on my marathons I used gels and had some breakfast beforehand usually two hours before race start. To be honest I dont think the gels made much difference to me. I think they have a placebo effect on people, perhaps Im wrong. Gels also give me an upset stomach and I never know when to take them properly. I also think because I dont know when to take them that by the time I do have one its too late! Currently im training for a marathon in April. I am trying out honey stinger energy chews at the moment. I ran 20 miles last weekend on water and these chews. I took one an hour into my run then another on the second hour. I cant say if they made any difference. I also agree with you FenlandRunner in that I know I have the energy to continue my runs but its fatigue that slows me down especially after 20 miles.
Feb 2015
1:00pm, 25 Feb 2015
1,501 posts
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I consider myself lucky if I go out for a run without having eaten shortly before and don't feel faint. I can just about do relatively hard efforts on minimal fuel (I've once or twice done parkruns pre-breakfast), but have found myself faint and barely able to keep upright 2km into recovery runs attempted pre-breakfast before.

I recall having to crouch into a ball at a set of pedestrian lights that had gone red against me on a recovery run before breakfast - my blood sugar dropped so quickly that my vision started narrowing and I was actually fearful of just collapsing into the road. A mars bar from the nearest shop remedied it all. Whilst that was probably the worst, I've several times found similar response on unfueled recovery runs.

I find my stomach behaves in a lot more unsettled a manor if there isn't something solid in it.

Some of the previous posts demonstrate that for some individuals running without food can be fine, but you need to take care, or there is a danger of actually doing yourself some damage.

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Maintained by mjoyeux
Just a couple of questions about nutrition and training:

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