IM Hydration and Nutrition

I've never done an IM but several 1/2 IMs.

What I'm going to say is most likely obvious but here goes:

1. you need approximately 250-280 calories/hour of energy (rest of energy comes from your body burning fat stores)
2. simple sugars are your enemy.  because one of 3 bad things will happen if you use them for energy.  (1) you can drink the 6%-8% concentration (required due to optimal osmolality for absorption), but you'll get too few calories to complete race (will yield about 100 calories/hour).  (2) you can drink MORE 6%-8% concentration in the hopes of yielding more than 100 calories per hour but you'll overfill on fluids because your body can only process a certain amount of fluids per hour or (3) you can dilute the simple sugars less (to like 10%-15% concentration to attempt to get more calories per hour but the osmolality will be too high and you'll get poor absorption (aka bloating)
3. complex carbs provide up to 3 times more energy but have the same osmolality (which means optimal hydration) as your blood and also as the 6%-8% concentration of simple sugars.
4. after about 90 min of exercise/racing you'll need to include protein (aka 8 essential amino acids) in your intake to avoid muscle cannibalization.

ok, enough preaching on complex carbs...i'm preaching to the choir in this part of the msg board I know.

with that in mind what I have done in past races is use a gel prior to the swim, on the bike wait til my HR stabilizes from being jacked up in T1 then begin to drink liquid complex carbs, once I hit the 90 min mark I switch to a protein/carb mix.  on the run I see how I feel but typically take complex carb/protein mixture every 45 min...in liquid form, usually in the form of a gel.  i also eat a pretzel every now and then just to make me smile!

What my coach did for IM was he had a HIGH concentration of Perpetuem in two 16oz bottles in cages and plain h20 up front.  he just sipped on the bottles at intervals and filled up the aero bottle up front with water from the aid stations.  this is such a good idea I think because:

1. he doesn't rely on special needs bags...which...yes...do sometimes NOT make it into your hands or you get someone else's
2. has ALL his energy in liquid form which is much easier on the body to digest, saving more calories for wattage output rather than digestive functions
3. never has to worry about what their "serving" at the race as he ALWAYS knows they'll be serving water!!

hope this helps.

Not veteran, but I've been experimenting alot with nutrition on my long bike rides.  I've settled on something similar to Steve's coach's method.  I have 2 bottles of Perpetum+CarboPro concentrate mix @ 1000 calories each.  I will have a third bottle of pure water to take with the concentrated mix.

Most important thing is to experiment,  what works for others might not work for you.  I tried some IM cocktails recipes online and my tummy didnt agree with some of the them. =p 

It varies from person to person, but I've done 3 IMs with basically this plan...

Per hour on the bike:  24 oz Cytomax, 2 oz Hammergel, 1/2 a Clif Bar, 1 Succeed capsule (2 if it's hot), and one to two bottles of water depending on the temperature.  That's about 450 calories/hr and 700-1000 mg/hr of sodium for the bike.  Note that I start the bike with 3 bottles of Cytomax and pick up another 3 from my special needs bag.

On the run, I'll take a few oz of Gatorade and water each aid station, and a shot of Hammergel with water about every 30 min, and continue with the 1-2 Succeeds per hour.  In the last 1/2 of the run, I'll take some Coke as I grow tired of Gatorade.

How has this worked for me?  Well, I've never really bonked.  I haven't had any real issues with dehydration.  I haven't had any classic signs of sodium depletion.  But, I have had some degree of stomach discomfort during the marathon.  My first IM was in very mild weather, and the 2nd and 3rd saw highs in the upper 80s to low 90s.  All I've done differently when it's hotter is to add more water and sodium, same calories.

I'm not sure if anyone really gets through the entire day feeling a-okay from start to finish.  Eating and drinking is the fourth discipline of an Ironman.  It's a lot to ask of your body to do all that work, and process all that food at the same time.  It's worked well enough that I don't plan to change anything this year.

One thing I've done each time, and will continue to do, is to carry a water bottle with me during the marathon.  I keep refilling it with water and ice at the aid stations.  It can be a great pick-me-up to take a cold drink or squirt some cold water on yourself between aid stations.  This has been at least a mental savior for me during those hot IMs.  That bottle becomes like a little security blanket.

Last, but not least, it's key to practice your planned race-day nutrition during all your long workouts, particularly your long rides.  Keep track of little changes you make from time to time, and how you feel at thee completion of your rides.  Sure your legs, and your butt, will be tired after a 5-6 hour ride, but monitor how you feel otherwise.  How is your energy?  Are you dehydrated?  Is your stomach sloshy, or feeling good?  If your nutritional plan is working for you, you should finish your long rides feeling pretty decent.  Get this dialed-in during training so your nutritional plan is second nature to you come race day.

Hopefully that's of some help.

-Steve

Steve,  I tend to agree with you because I've read literature that the body can only process 250-280 cal an hour and any extra just stresses the body.  HOWEVER,  that I believe is just a general guideline. 

ALot of elites and pros take MORE than that.  Gordo for example, who just got second in IMNZ, ingests about 400 cal/hr.

Food for thought

Sure there are always personal tweaking to do, however it should be noted that as an average the liver can only produce 260-280 calories per hour back to the body (give or take depending on how fast your liver can do this).

My point is that just because you're heavier doesn't mean you have to take in more calories.  One of the biggest mistakes beginner triathletes make is to injest too much calories.  The misnomer is usually that if they are expending 600-800+ calories an hour, then they need to replace this by outside fuel....

When infact the body does an excellent job and providing up to 65% of this caloric expenditure through the wonders of fatty acids.

I didn't want people to read this post and think that they need to take in more calories just because they are heavier (in general).  Sure you may need a "few" more calories if your heavier, but not 100% more calories than the "average" the body can metabolize.

Again, you don't want to be using energy to digest food, but to race.

Steve is right.  Dave Scott himself told me last year that your goal is to replace only about 1/3 of the calories that you expend. 

Steve is wrong.  Bigger people process calories faster.  It just follows that a 6'5" guy (like me) has bigger internal organs than a 5'8" short dude. 

My approach leading to IMAZ is to shoot for 350 cal/hour in gels and bananas and an extra 100 or so in Gatorade Endurance.  So far on my long bike rides, this has worked well - no undue bloating or other GI issues.

By nearly a foot...

Must be because the big guys are slower and race at a lower HR so they can process more calories per hour...

(joking....I'm just joking....)

I won't be sticking to my 1/2 IM nutrition plan....that's for SURE!  From what I'm told, the 1/2 IM is about as similar to the IM as an Olympic is to a 1/2 IM.

I will shoot for 260 cal/hour during my long trng sessions, with 100% liquid diet...most likely Perpetuem with endurolyte pills to supplement...but I have to see how that does with my GI and may possibly change to another brand of liquid diet if my GI has discomfort.

I hope to tweak my nutrition so I don't need my special needs bag on the bike....aka try to mimic my coach's nutrition plan as close as possible and see if that works for me during trng.

I've noticed a HUGE difference in GI distress when injesting simple sugars compared to injesting complex sugars and will most definately NOT be drinking any coke or eating any gummy bears, tootsie rolls, etc

I'm doing several rides over 100 miles during the season (a couple of them bricks of course) so those will be the best "trial runs" for tweaking my nutrition plans...although they won't be at "race pace".

The one thing I know for sure is that during the IM regarding my nutrition plan is:

IMPROVISE - ADAPT - OVERCOME 

.

I wanted to share a little of my experience from my long ride yesterday.  I thought this was a good place on account of all the previous posters. 

I think that the weather in South Texas yesterday was similar to what we'll face in Ironman Arizona.  It was about 48 degrees when we left at 10 'til 7, and by the time we finished, 6.5 hours later, it was 80 or so (and extremely windy).  I started out with sipping a little Gatorade Endurance and water every fifteen minutes, and it was too much.  Literally.  I had to stop to pee once an hour for the first three hours.  I peed again after another 1.5 hours, but not a whole lot.  Then, in the last couple of hours, I started noticing that my mouth was getting a little dry.  Uh-oh.  I ramped up the hydration, and probably took in about 30 oz of water and 15 oz of G-E in the last hour alone.  I think I caught it in the bud, but my partner, who made it back to the start about 15 minutes after me, said that he was dehydrated.  In all, I took in 76 oz of G-E and 90 oz of water in the 6.5 hours we were on the ride, and half of that was in the last third of the ride. 

My point is this.  Hydration needs are very dependent on the weather.  I was drinking at a rate of about 15 oz per hour at the beginning, and I peed every hour.  I was drinking at about 45 oz per hour at the end, and it was just enough.  Pay attention the the environment, especially during an IM race, and be prepared to take in LOTS more fluid as the day warms.

That's all for now...  Anyone need a slightly used soap box?

Traveski - 2005-03-11 6:59 PM Wow, 5'8" is short you say.  What is 5'6" then!?!?  I may only need to consume 1 banana over the IM course!!

I have to say that this is truly an interesting thread. Unfortunately, I have nothing to add since I'm really inexperienced in this IM business.

I might eat half a banana though and two sips of gatorade; I'm only 5'4"

Please keep the good advice coming for us IM newbies.

Félix

Has anyone used Champion Nutritions' Revenge Pro in IM racing or training?

Unfortunately, here in Venezuela this is the only "carbo drink" I've run accross. Can't find Perpeteum or CarboPro and ordering such from abroad is definitely troublesome (my country is undergoing foreign currency restrictions). Any comments?

Félix