Ugh. Fuel**** not feul

glevinso wrote: »

Carrieendar wrote: »

glevinso wrote: »

Carrieendar wrote: »

I think it boils down to that there is risk involved with taking in anything while you are running. Knowing that they can safely and effectively run for 2 hours without taking in anything and have no detrimental effects on their time, many runners chose to not fuel during a shorter race.

What I bolded is key though. Many runners say they don't need to fuel for a (example) half marathon, but if you look at their times they are incapable of a negative split. If you *can* demonstrate a negative split over that distance and not take in anything, then I would say yes you don't need to take in anything.

I would argue poor training or race strategy over the need for feul for the shorter race.

But training your body to be dependence on a blood glucose spike for performance by continually feuling on all training runs can be the problem as well. That's a problem you can't fix race day. And, if that's you, just feul and worry about it next time around!

Note the above is based on knowledge of physiology as it relates to running. I have no idea when it comes to tris

I am not sure there is such a thing as a physiological adaptation to glucose spikes, but I could be wrong

I think at that point it's a mental adaptation for identifying whether or not your body is able to continue moving.

Everything out there makes me dry mouthed and thirsty. The only exception being the chocolate flavoured Cliff shot gels or Gu or some tiny candy bars. I have exercise induced migraines and I found out that I don't have one if I get some sugars in at miles 4 and 10 during a HM distance. The best part is I feel fine at mile 4 sometimes and don't get the gel and then I'm having a crushing headache just past the 10k mark along with neck and shoulder pain. Then I'm going for the emergency ibuprofen instead. Not fun

OK. I get the concept then of training your body to store more glycogen by not refueling as often (or at all) on long runs. I just have never really seen any guidance on how best to do that. I guess from all I have read it seemed like it was something that might start happening as you run more. Now though, I'm not so sure.

I guess after these two halfs coming up in a few weeks I'll start running long without any refueling on training runs. So far I really only refuel on long runs, but I do what I would do on race day. Looks like I should rethink that.

This is why I like to ask these sorts of questions.

Yes, if you can run the half from 90 min-2 hours then taking in gels during the race is not going to make you faster. Your body has plenty of storage for that time. I can post some references if people want. Many require journal access, but if you are a university student or the like , you can access them through a library code.

grimmeanor wrote: »

OK. I get the concept then of training your body to store more glycogen by not refueling as often (or at all) on long runs. I just have never really seen any guidance on how best to do that. I guess from all I have read it seemed like it was something that might start happening as you run more. Now though, I'm not so sure.

I have never heard of this and I have been doing long distance races (Ironman) for years. This goes against everything I have read and experienced myself.

I am curious to see this, as it doesn't make sense to me. I want to know what the actual mechanism is that causes this fat-adaptation. But then again I am coming from a background of Ironman training and a "long training day" for me can easily be 6+ hours.

I will say that the only time I ever "fuel" during training is on my long rides or long runs. Everything else I do is under 90 minutes at a time. Even on double workout days where I'll have two one-hour workouts I always separate those with an 8-hour workday and obviously eating during that time.

Ahh perhaps I already do kinda do this in a sense. I don't really subscribe to the "LETS ALL EAT KALE!" thing that many newer triathletes get into. I have been around long enough to know that I just need calories. A lot of them. I eat bacon almost every day

But I also don't restrict carbs, or really even think about my macro balance. I just eat food.

As for long training without fuel - I'll go up to 14 miles without anything, but past that usually only 1 or 2 gels.

Carrieendar wrote: »

. Greg mcmillan (from the mcmillan calculator fame lol) coached me last season and he recommended 5 of my 10 long long runs and all medium longs be done in a fasted type state to increase my body's ability to burn fat and force more energy storage.

We are in agreement on taking on fuel during training runs but I continue to disagree with you IRT fueling during a half marathon.

Is it that you don't believe the body stores enough for 90-120 or that the stuff you ingest is somehow utilized better than the stuff already there?

ugh, sorry about the size. not sure how to fix that...

It is adapted from a Feling and Wahren study that took blood samples from runners as well as muscle biopsies over a period of training and racing.

Carrieendar wrote: »

This is a figure from one of my physiology textbooks. It plots the plasma concentration of glucose and glucagon over time during endurance exercise lasting 240 minutes. As you can see, the body easily handles the exercise up until about the 90 -120 min mark here before glucagon levels increase rapidly .

I'm assuming this study was done with well trained athletes? For recreational runners, does this still hold or do they tend to run out of fuel earlier?

The_Enginerd wrote: »

Carrieendar wrote: »

This is a figure from one of my physiology textbooks. It plots the plasma concentration of glucose and glucagon over time during endurance exercise lasting 240 minutes. As you can see, the body easily handles the exercise up until about the 90 -120 min mark here before glucagon levels increase rapidly .

I'm assuming this study was done with well trained athletes? For recreational runners, does this still hold or do they tend to run out of fuel earlier?

Again, I think the point is there is a built-in time limit to the glycogen stores and how efficiently you utilize the energy. Someone like me, who is going to run a half-marathon in two hours or so, is just not going to need it. Someone who runs the half-marathon in three hours, maybe or even probably needs some supplemental fuel. But it isn't such a simple relationship as time or training.

My HRM program gives an estimate of calories burned and what percentage comes from fat along with custom heart rate zones. As I have progressed, my lactic acid threshold heart rate has increased from 168 bpm to over 178 bpm. But the other thing that has occurred (in part because of the way I've trained with slower runs for greater volume) is that in each of the last three half marathons, I have gotten progressively faster, my average heart rate has gotten progressively slower and the estimated calories from fat as a percentage of total expenditure has increased. But its only an estimate. The fact that I tend to run moderately long distances (up to HM) fasted and without supplemental fuel is probably a help (according to Fitzgerald) and not a hinderance.

In each, I have taken a single gel about 15 minutes before the race start to "top of the tanks" so to speak. But my carb loading plan for the half marathon is really no different than the full. In the last race, which was half-marathon just a few weeks before the full, I added a gel about midway while running at my HM pace, more to see if there were any problems associated with taking in fuel at that high energy output rate. Other than staying completely in control of my running pace because I viewed that race as the last long "high-speed" training run, I can't say I felt any different from the races where I didn't take in anything except water during the race.

Also I don't fuel much up to 13 miles. Maybe I fill my water bottle with some sports drink and I do carry something in case I need it but I focus of fueling myself really well before so I need minimal intake during the race. Longer than a half I will fuel though. It's taken years of racing for me to truly find what works for me and now it's just second nature.

There is a significant difference between "running" and "racing". When I see elite's stop fueling during their half marathons I'll consider it.