Gotcha. Fully understand.

I've got my first iron distance race coming up and I'm already sold on liquid calories. Determining the right amount has me a bit stumped though. It seems like you, and others, are suggesting around 1800-2000 calories through an IM dist bike leg. Do you then need to continue to fuel throughout the run or do you just finish with a huge calorie deficit?

Using the rule of thumb of 1kJ to 1kcal a 6 hour bike split on 170W (case example) would result in an expenditure of 3672kcal. What am I missing?

Welcome to all input!

---

Practise doesn't make perfect, practice makes permanent. Only perfect practice makes perfect!

Also have a question about liquid nutrition.

So I have 3 places on my Canyon Speedmax SLX where I can put liquids:
1)Profile/Canyon energy&hydration source with large straw between arms (I guess it's less than 500 ml).
2)Elite Aero bottle on down tube (500 ml).
3)Back seat bottle (750 ml), but it's very difficult to get the bottle from this cage and put it to it.

I wonder how's better to deal with the nutrition (I'm planning to use Perpetuem) on HIM and full IM.

Half Ironman:
1 - water
2 - perpetuem
3 - perpetuem

Full Ironman:
1 - water
2 - perpetuem (probably, replace the aero bottle by regular 750ml bottle?)
3 - perpetuem
+ some bars or gels in pockets.

Should it be enough? I'm little bit worry that I won't have much space to hold all perpetuem I need.

If I am understanding everything that I have read correctly, this is my understanding.

Your body has enough glycogen stores for about an hour of moderate to intense level of exercise. With the fueling that you are doing on the bike section you are merely giving your body the fuel/sugar that it needs to continue burning efficiently without having to go to the fat stores. Your body is not efficient at burning fat and your speed, power and performance drop drastically.

So to answer your question directly, what you are missing is that you are stuck on the calorie numbers only and that isn't the whole picture. Calorie wise you are going to end the bike and run on a major calorie deficit. What you are merely doing is giving your body the carbs, sugar and protein to constantly burn so it can continue to give you the efficient energy you need rather the it trying to burn the fat you have.

As for the calorie intake pr/hr can get you in the ball park of where you need to be but, that is why you test before you train because the calorie intake may not be enough for you to sustain the performance output you want.

Biggest thing you need to figure out is how many calories per hour your body can absorb - because you'll never be able to replace everything you burn. If you try, you'll be in for some major digestion issues.

The rule of thumb I seem to recall is that most people can do 300-400 calories per hour. I typically do about 350-400 calories per bottle (2.5 scoops of carbopro and 1.5 scoops of Skratch Labs), and use 4 bottles for an IM. Water I drink from the course. Probably need to work on getting a bit more nutrition in, but I'm in the ballpark as to what I can take.

---

___________________________________
MS: Exercise Science
Your speed matters a lot, sometimes you need to be very fast, where sometimes you need to breakdown your speed.

Ultimately, i end up doing gels on the run. One every 5k for the first half of the race (I put 4 in my pockets in t2)

Then, I turn to aid station food (really enjoy salted chips and a banana)

Lastly, I'll use the coke at aid stations, but I save it as long as I possibly can, because it feels so freaking good when I start drinking it, but seems to fade after repeating for 5-10km

I use an aero water bottle on the down tube that is a mix of my gels and water. It tastes okay, not great, but it is easier than trying to deal with gels and their wrappers mid race.

From an optimal fuelling perspective I think liquid calories are absolutely the way to go. Any races short of IM I get 100% of my calories in liquid form, in IM I do tend to take on a few solids simply because it's a very long day and I need some variety. I'm also not in contention for podium or KQ, so not overly fussed over a few minutes here or there.

The flip side of that is that liquid calories are pretty sugary and sickly, I don't particularly enjoy drinking them, they're bad for your teeth, and they tend to result in me, my bike and my clothing getting sticky which I find pretty unpleasant! So unless I'm actually practicing my race nutrition strategy then in training I typically get my calories from solids and only drink water. And for training <2 hours I use water only. I rarely run >2 hours these days but when I do I typically use jelly beans or jelly babies, cheaper and tastier than gels!

I am planning on doing the same. Have you tried freezing the bottle overnight? If so, does it work?

---

Love the Pain!

Quito-Ecuador