I don’t now how he does it! I need a bike-he writes about small tri bikes for women. I need help with refueling-et voila! Great article and research-thanks, again.
That article was sweet. And the link to Monty’s evacuation article was especially enlightening 
Agreed, what a fantastic article and extremely well articulated. One of Dan’s best for sure and something I wish I had when I started this sport!
Mark
Yes, nice article, good info, well written.
So for races less than 2hrs hydration is the biggest problem and for IM/HIM plenty of fueling info in Dan’s article. But what about that pesky Olympic distance, a little too long for just hydration but gels/2-3 20 oz bottles of fluid replacement, that seems unnecessarily complicated. I guess the question is how does this fueling info scale for races 2-3hrs long?
For olympic distance, one bottle of Gatorade on the bike maybe one cup coming out of T2…that’s it. Anything more and it just sucks blood to the stomach and away from the legs. If you have a solid breakfast, there should be no need for anything at all.
perfect timing for me, since IMCDA is less than 2 weeks away. and also a perfect fit. he was talking about 1:15 swim and 6 hour ride, my estimated times. thanks dan, you are a psychic
I compare him to Aristotle and Socrates-they get to sit around and think. and think outside of the BOX!
Thanks for the input. I did my 1st Oly last weekend and really, really struggled after 2 1/2 hrs. I used the 1 gatorade on the bike, 1 gatorade before run plan so I didn’t really feel badly underfueled, just wouldn’t go when I pushed the go button. So now I’m thinking undertraining was the bigger problem.
“thanks dan, you are a psychic”
i knew you’d need this article. i have espn.
Slowman and board,
Re fueling, often times when I am out on a long ride or run and end up dragging @ss, I wonder if it is because I have bonked or because I am simply out of shape!?
Seriously, anyone know how to differeniate the two. Often times people will say they bonked, but maybe they just rode too hard or were not ready for the distance. This compounds the fueling decision strategy. I did IMH twice recently and folded on the run. Was it because I bonked or because I was simply tired? I really don’t know.
Should I?
“anyone know how to differeniate the two.”
go on a 4hr ride. ride very comfortably, even easily. just drink water. you’ll bonk. that’s what a bonk feels like. remember that feeling, try to avoid in the future. bonks occur in 15 minutes. out of shape is constant.
Dev, for an oly distance, and I do 2:15 to 2:30, I take 3 gels before the swim, starting an hour before my wave start, one every 20 minutes on the bike for 3 more,
and then go for it in the run. I have yet to bonk, or have GI issues with this approach.
Dave
Dan,
Your article is frankly good, but I would like to add some additional thoughts that might help … pure science here can really help and if others who deal with the medical issues here want to add in this could be really useful. I will try to make it simple … but it often isn’t.
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I feel really uncomfortable with the discussion about NSAIDs (Motrin, Advil, Aleve,Celebrex, Naproxen … and many other names). It is true that one can benefit from these with pain/inflammation relief … but I think we should warn people that their use really might have serious side effects in many individuals such as renal failure, GI bleeding, hyponatremia … not good stuff and it really occurs … especially in dehydrated stressed athletes (like ultra distance racers). People should just really be careful here. I personally often take 600mg of Ibuprofen at mile 13 of the run … but I don’t use it at all otherwise and I would not recommend it at all for others unless they are really “body familiar”.
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The most important concept is osmolarity (you refer to it as solvent/solute ratio). This has to do with the amount of substance… mostly salts but also sugars/proteins mixed in water. Normal human osmolarity is 280-290 (I’ll skip explanation of the units). What that means is that anything you take into your GI tract that is higher than 290 will draw fluid into your intestines and potentially bloat you … the higher the osmolarity … the more the effect. Osmolarity is available on labels for most sports supplements. I don’t want to advocate any specific product … but for those familiar the Infinit line lets you see the osmolarity of what you mix and rightfully encourages you to stay close to the 290 range.(I don’t use Infinit personally, but I think it supports good concepts). Many people concentrate their sports powders that they carry so they can get the calories they need in … but those concentrated mixes have huge osmolarities when done that way and so you are guaranteed to bloat unless you are very carefully adding water in in large amounts. If you understand and pay attention to osmolarity, it will pay great dividends to you in your race.
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The type of sugar you use is major. Glucose is bad because it causes decreased stomach empying (gastroparesis). The more complicated the sugar molecule the less effect on gastric emptying … so maltodextrin/ fructose will be better tolerated. The effect of poor sugar choice is vomiting up your stomach contents. I would be glad to have gatorade inform us better … but I have always considered gatorade to be …in my opinion… sugar death in an ultra because of the glucose content and I won’t touch it. I do great with it even to a 1/2 IM … but not above that distance. If you look at the sugar type content of popular gels … you’ll quickly see why they are popular.
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Dave (h20 fun) mentioned his intake before swim … I think people really miss a nutrition opportunity here as they can put in some significant calories that will get absorbed in the gut early during the swim which is less gut stressful. Start your calorie replacement right as you get body marked!
I’m going to stop here because I think the above issues are the most important additions. If some other MDs or sports nutrition people want to join in, this could be good stuff for everyone.
Dave
“I think we should warn people that their use really might have serious side effects in many individuals such as renal failure, GI bleeding, hyponatremia”
i thought i adequately did that in the article. but in case i did not, your additional warning is something that readers should take to heart.
“The most important concept is osmolarity”
not to be picky, but probably more would cite osmolality. in either case, yes, you’re right, and that’s what i refer to when i talk about user devices for throttling back the saturation in your stomach (e.g., clear water with gels). one thing that’s tricky is considering the number of “equivalents” that go into a mixture, and by “mixture” i’m talking about that big water bottle that is your stomach. specifically, it’s the salt tablets that get me concerned. on the one hand, it’s obvious, apparent, that certain people do very well with them (and i mean a lot of them). consider jonnyo’s eyebrow raising intake at his recent IM. on paper, you’d think the osmolality of his intake would be way too high, shutting down his ability to absorb. but a lot of these guys just eat those things like candy during an ultra.
any wisdom you or anyone else would like to share osmolality / salt tablet thing is welcome. just be advised that there really is a paradox here, and i don’t know that this is a solved issue.
Dave, I actually got the input about taking gels before the swim from someone on ST. The comment about taking them an hour before the swim,
and 20 minutes apart, was to get the sugar level up and leveled, I think, rather than lots of peaks and valleys. It seems to work well for me,
so I pass the idea to others that are having issues bonking.
Dave
dan, when you said some athletes drink 2-3 bottles an hour, did you mean 22 oz bottles?
I have been trying to figure out my nutrition and with my first ironman coming up I’m nervous. I have finish my last two half ironman’s (TTT, and Rockman) in the last two weeks feeling great in the race but terrible 20 minutes after. my veins collapse after the race when my blood pressure drops and I’m nauseas. During the ride I am probably getting about 40z an hour and during the run I refill a 20 oz bottle at each aid station and make a pretty good dent in it by the next. Yet I bet I’m still losing 5-7 pounds by the end of the race (I’m 6’2" and 165). I’m really doubting if I can finish the ironman on 8.26 with respect to nutrition. at the TTT I was drinking the infinit with 375 mg of sodium/ 16 oz and at Rockman I was taking 4 salt stick caps an hour (215 mg each). After the first race I definitely had hyponatremia. I’m not sure if I did after the other race or not. I took a bunch of salt caps and drank as much water as I could and then got a bag of chips down before feeling better so that makes me think I was.
Does anyone know of a sports science lab I can go to in order to be tested?
Thanks a lot,
Dan
www.aiatriathlon.com
Dan,
Your article is good …I was just trying to expand on it … your additional points are great.
Salt (NaCl) is a major determinant of osmolality … there actually is a formula to roughly calculate it medically that emphasizes that. Clearly salt tablets taken in large amounts raise the number unless they are diluted out with water … maybe that is the key. Na and Cl also move easily across the bowel wall which may limit the osmolar effect time wise.
I use a lot of salt tablets myself even though I’m pretty heat adapted living in the desert … I only use them with IM distance races and not in training much. I’ll finish a race crusted in salt … mostly because I’m oversupplemented. It keeps me from getting cramps and I think also helps me stay hydrated better and less likely to become hyponatremic even though that is a little more complicated issue.
Dave
“when you said some athletes drink 2-3 bottles an hour, did you mean 22 oz bottles?”
i don’t remember what i wrote, quite frankly. and it’s the end of my writing day. let’s see, there’s 20oz and 25oz typically, no? yes, let’s split the difference and say 22oz 
interesting about your experience. i think that’s a bit above my pay grade. i’m sure there are more knowledgeable people than me who can address this.
thanks Dan. Hopefully someone will see this and post.
My understanding is that people usually gain weight with hyponatremia and its usually from overdrinking not undersalting…
Sounds like you are drinking a lot - 40 oz.hour on the bike + most of 20 oz at each aid on the run (which would be each mile???)?
“After the first race I def. had hyponatremia” - how do you know?
Dave