Hi, Runners!
This is a review of a previous blog post I wrote a couple of years ago. Some of you will have seen this already, some of you have not. But it’s important race-nutrition information.
Many of you already know what works for you on the run, but there are those of you who are new to this as well. This is information I have shared before, but it’s always a good refresher.
There are so many options. So where to start?
Our bodies break down different sugars to use a fuel in different ways.
And here’s news for you: Everyone’s body breaks down sugars differently. This is why there are so many options out there. Carrier proteins absorb and metabolize sugars in our bodies – and everyone has a different mix of carrier proteins, which is why some nutritional substances work for one person and not another. It all comes down to sugar and how well our bodies process and transport each type of sugar.
Glucose Transporter GLUT2 is what absorbs and metabolizes glucose and maltodextrin – at a rate of up to 1 gram/minute. GLUT5 is what absorbs and metablizes fructose (fruit sugar) at a rate of up to .6 grams/minute. These are the two main transporters that we concern ourselves with as runners. An ideal mix between GLUT2 and GLUT5 yeilds an absorption rate of up to 1.75 grams/minute. Water is what makes these sugars fluid enough to travel through our bodies, so all nutrition must be consumed with water to be effective.
The best thing you can do is to experiment with what sugars and what sources of fuel will work best for you. All of our nutrition items have all of the types of sugars in them, just in different concentrations. If you don’t do well with a certain type of sugar, find a nutritional item that has a higher concentration of a different type.
Sugars
- Fructose
- Low GI (19)
- “Fruit Sugar
- ~19ml/g of water to be isotonic
- Absorbed via GLUT5
- Sucrose
- Medium GI (65)
- ~19ml/g of water to be isotonic
- Bonded Glucose & Fructose molecule
- 1:1 ratio of these sugars
- Glucose
- High GI (100)
- ~19ml/g of water to be isotonic
- Absorbed via GLUT2
- Maltodextrin
- High GI (~105)
- ~3.3ml/g of water to be isotonic
- Absorbed via GLUT2
(Note: GI refers to Glycemic Index – or the rate at which the body breaks down a carbohydrate. The lower the number, the slower the carbohydrate is broken down)
Here’s what we have:
High in Glucose/Maltodextrin:
Gu, Gu Chomps, Roctane, Cliff Shots, and Cliff Blocks
High in Sucrose:
Sport Beans
High in Fructose:
Huma
So what do you take away from this?
- A product which contains sugars using both pathways mentioned will be capable of delivering the most energy
- If you don’t consume water, you won’t be able to take full advantage of your race nutrition and will likely experience gastrointestinal distress
- If you experience GI distress try consuming your nutrition more slowly, make sure you’re consuming enough water, try something with a different blend of sugars
- PRACTICE
- Best absorption rates can be reached by eating small amounts of nutrition at a time, consumed with water
- Ideally 1 serving will take at least 2-3 minutes to consume
- Remember the Golden Rule of Running, “Never do anything new on race day.”
If you haven’t started figuring out your race day nutrition yet – get on it! We have a lot of options at Gazelle Sports, including those mentioned above, plus more!
Try some different things out. It’s imperative that you figure this out before race day.
Your Challenge this week is to come up with a nutrition plan. Do you know when you’re going to take your nutrition during your race? Do you know when you’re going to eat before hand (we’ll discuss this more next week)? Do you know what you’re going to use during the race? When you’re going to hydrate? There’s a lot to think about when it comes to distance running and nutrition – so start thinking about it, and practicing it during your long runs!