Iron distance fueling (Page 2)

we are talking about someone's ironman race, even nice isn't that difficult. and i would agree, the total calorie demands are dictated by the time on the course, but that does not equate to what you initially stated.

OH, I wanted to say that in preparing for the event, and knowingly going into it on less than adequate training, I found a lot of useful information in these forums.

I trained with power and rode with power on the bike leg.  Knowing my FTP and lengthening my training rides while maintaining desired power levels, I determined a ceiling power for the ride.  I hoped that if I was disciplined enough to keep the power down I would have something left afterward. It worked.  I tried to keep the power under 150 (my actual was 144 so I was slacking).

yes, but as you go uphill you store potential energy = mgh, that you get back going downhill. so your total energy consumption is much more equivalent to a flat. In fact, a flat with a headwind could require more energy because you may not get an equivalent tailwind later, while you will always go downhill the same you went up. 

Regardless, calorie requirements arent goverened by your calorie expenditure. You are not looking to replace all the calories you consumed, just put in as many calories as you need to keep moving. So whether it is a flat course or a hilly course, you have a very similar calorie requirement for an Ironman.

I'm not a coach, and I will stand by my statement that calorie expenditure does not govern your intake requirements for a race.  In a Sprint I'll burn around 1,000 calories, and take in ZERO.  In an Ironman I might burn 10,000 calories, but I'm sure as heck not eating that much.

Your body can only take in XXX calories per hour, depending on the person. So if its all uphill you will be eating say 300 calories per hour. If its all flat you will still be eating the same amount per hour, even if more calories overall were burned during an uphill race.

x2.  Calories consumed has virtually zero correlation to calories burned.  Calories consumed are dictated more by how many you can digest, and even then, IME, more people over-fuel than under-fuel.  I've personally completed a VERY hilly 6:48 HIM on approximately 800 calories and felt great.

Also, calories burned for s/b/r can be estimated most simply by using these formulas and forgetting about hills (unless it's a point-to-point course with a significant net elevation gain or loss):

Swim 100 cal / 400 m

Bike .35 cal / kgkm

Run 1 cal / kgkm

There are so many other variables that tend to either cancel each other out, or are too complex to quantify, that these simple formulas are accurate enough for most purposes.

A couple thousand calories stored in glycogen, + a couple of 10,000 calories stored in fat (Nobody is 1% BF, even pro triathletes. Low single digit body fat causes all kinds of health issues. I've never seen statistics, but I'd guestimate that most are between 7% and 10%.) + fuel consumed in the hours before the race and on the course = plenty of energy for an IM with much to spare.  There is no fuel issue.

I'm curious why you say that burning fat causes you to be slower?

ETA: You questioned how someone can burn 2x what they consume and not run out of energy.  In the race I mentioned in my other post where I consumed 800 calories, I estimate my caloric burn at 4,000+/-, so I actually burned about 5 x what I consumed. 

You do realize that plenty of people run marathons without taking in any nutrition, right?  I've only ran one, but I didn't take anything but water.  I ran a HIM and ate 2 hammer gels on the bike and ended up sucking down a couple cups of coke on the run......felt fine.

I'll work out the IM fueling for the race I'm training for.....but I don't plan on needing a buffet.

You burn a combination of fat and glycogen as you excercise. It is not an either or, it is a sliding scale.  The harder you go, the more the scale slides towards glycogen because your body is able to burn it at a higher rate.  In a marathon or Ironman race, you cannot go at a pace that burns mostly glycogen because you do not have enough reserves in your body to do that indefinitely. (Maybe a pro marathoner could get away with it running a low 2:XX marathon. but none of us are doing that).  It is true, eating helps you to go a bit faster, but this is because it is keeping your blood sugar from dropping too low and is providing you with some easier to burn fuel to supplement your glycogen stores.  Go out for a workout, run hard for 3 hours, and try to actually consume 3,000 calories of food. You will soon find that you not only can't eat this much, but that your body will not process and digest the food effeciently if you are at a high work rate.  The body diverts blood flow away from the digestive system at higher efforts to bring more oxygen to your muscles. You have to find a balance between effort, calorie intake, race length, and fitness to really plan out your ironman (or marathon) pace and nutrition. I would recommend trying out your nutrition plan on your training runs to really dial it in. To start I would try 200 calories/hour and go from there.

My experience, in training for this event knowing that I would have fueling issues, correlates with your statement.  Because I monitored my blood sugar level to the extent I did, both during training and non-training, I found that eating could be counterproductive even when it was food that did not create a blood sugar swing.  This loss of energy was apparently due to the body diverting its attention from what I wanted it to be doing to the chore of digestion.  In all honesty the only reason I ate anything during the IM was because I knew from training rides that my stomach would let me know that it was empty at about 100 miles (hunger pains I think they are called).  I am pretty sure I could have completed the distance without eating but that was due to the low energy expenditure because I went easy on the bike.

I think that your statement, "really dial it in" hits the nail on the head. Everybody and every body is different and what they need, whether perceived or actual, is going to be different and though there are rules of thumb that can be used as a starting point it is best to put in the time and figure out what works best for the individual.

I had a lot of tests run on Tuesday because I woke up SICK with high fever from a UTI.  I went to the Dr. and then to the hospital (where I stayed for a few hours). 

The results of the tests were interesting in that my CK level was 653 (not sure of the units) and normal is around 150-170. I did some research and found out that a 600-700 value is not uncommon 48-72 hours after completing an IM.

There was a protein level (don't recall the name) indicative of muscle break down that the kidneys have trouble filtering efficiently.  This caused the Dr. some concern and was the reason I had to lay around for an IV. I was not dehydrated (I promise).

I discussed, with the Dr., the likelihood that the protein level was due to my fueling and would the UTI be also attributable.  Dr. said the protein was probably due to my muscles breaking down for fuel and that the UTI was NOT related to that.

In another thread http://www.beginnertriathlete.com/discussion/forums/thread-view.asp?tid=482528&start=1 there is a discussion of whether it is possible to complete 140.6 miles without any fuel at all and I would have to say, "yes. without a doubt." (There's a line from the wiki entry on the Bataan death march that says, "Prisoners were given no food for the first three days, and were only allowed to drink water from filthy water buffalo wallows".)

This thread, and the linked one, remind me of my prevailing thought this past week, "No more hundred mile training rides!"  I LOVE to ride a bicycle. It is the closest this 51 year old man gets to being a kid again. I love mountain bikes and road bikes and time trial bikes, but it got to the point that I didn't enjoy going for a ride I felt obliged to go.  The posts, on this topic, have ranged from incredulity to contentious to almost calling people fibbers and I don't understand why.  This is supposed to be a sport and this site is supposed to be aimed (I think) at providing encouragement and support to those who want to participate and not deriding and defaming.

My only regret, from the past weekend event (besides the fact that my mom fell down the day before the race, broke her leg, and couldn't see me in the ONLY IM distance event I will ever be in) is that I could have gone harder.

I am thankful to those who have sought to understand my statements and I appreciate the information I have obtained from this site.

Peace.

JWR