How fructose improves performance in endurance athletes

Fructose sometimes gets a bad rap for endurance athletes because it is thought to cause stomach and GI discomfort. Like anything else, if you take too much fructose it can be a problem. But if you use it properly it can actually significantly improve performance … without stomach issues.

Here’s why:

Most of the energy that we use during endurance sports comes from consumed carbohydrates that are converted into glycogen and stored in our muscles. Glycogen can then be quickly broken down into glucose and used to fuel the muscles. The liver also stores glycogen which has been converted from fructose and serves as an additional “fuel tank” to power your muscles.

here's where it gets interesting

The main route for glucose absorption from the gut is through a transporter called SGLT1 – a protein that acts like a door, helping glucose go from the gut to the bloodstream. SGLT1 has a maximum capacity and can only transport around one gram of glucose per minute (240 calories/hour). Fructose, however, is absorbed with a different transporter, called GLUT5. By using both transporters you can increase the amount of carbohydrate the body can use during exercise up to approximately 300 calories/hour.

GLUT5’s sole job in life is to transport fructose, so if you’re not consuming fructose then you’re not using the GLUT5 transporter … it’s like have an additional fuel line and not using it, why would you do that? In addition, your secondary fuel tank (your liver) will be under utilized as well.

The rapid absorption of fructose mixtures and special handling of fructose in the liver are the two main reasons that fructose can also help to speed up recovery after exercise. A recent study found that when athletes drank sports drinks containing both fructose and complex carbohydrates after exercise, they accelerated the recovery of their liver glycogen stores. It almost doubled this rate of recovery compared with drinks that didn’t have fructose, when the same total amount of carbohydrate was consumed.

bottom line

If you want to “be your best”, incorporate some fructose into your training and competition nutrition program.

Both e-Gel and e-Fuel are formulated with this in mind. The main ingredient in our products is maltodextrin, a complex carbohydrate from corn. Added to the maltodextrin is fructose in levels that can be efficiently processed and stored by the liver, thus supplementing your total available energy without causing stomach issues.

fructose research references
Don’t just take our word for it. Independent scientific research has consistently shown that using fructose and maltodextrin together increases total carbohydrate transport, available energy and oxidation (Jentjiens, 2004, Wallis, 2005). The combination of fructose and maltodextrin also allows an athlete to exercise at a higher percent of VO2max, once the muscle glycogen stores have been depleted (Smith, 2010).

if you found this useful please share!

Share on facebook
Facebook
Share on twitter
Twitter

related resources

gels, drinks, chews ... what's best for your sport?

Use our Sherpa Nutrition Guide tool to get your nutrition dialed in. Just plug in your sport, problems you’re having (cramping, stomach issues, running out of energy) and Sherpa will give you a detailed person guide. Free, quick and easy!

what is an energy gel and who should use them

Many people are not fans of energy gels at first because they can be sticky, thick and hard to get down. Why would anyone use an energy gel? Why not just stick to energy bars and sports drinks? All good questions… read on

when to use energy gels and sports drinks and can they be used together

If you decide to use e-Gel and e-Fuel together (or any energy gel and sports drink), follow these guidelines for best results.

energy gel comparisons

See how your energy gel stacks up

hydration and proper use of energy gels

Before building an energy gel into your training and competition program, it is critical to understand the importance of proper hydration.

energy gels are a better choice than bars and chews

Protein bars, energy gels, chews, hydration drinks, fruit … what should you use? Making the right selection can significantly improve performance.

marathon training with e-Gel

One of the golden rules of running a marathon, triathlon or any endurance event is to not change anything on race day, and this applies to your nutrition as well.

ingredient articles

electrolytes in energy gels

Why is this important?

caffeine

Our recommendations on when to use caffeine and when to avoid it.

hyponautremia, electrolytes may save your life

Over hydrating and not getting enough electrolytes can lead to a condition called hyponatremia, which is serious and sometimes deadly.

race tips and strategy

the marathon wall and how to avoid it

The bad news is that “the wall” is a very real thing. The good news is that you can avoid “hitting the wall” if you follow this advice.

marathon race day tips and nutrition strategy

How much should you drink before and during the race? When and what should you eat? How many gels should you use?

how to avoid the porta potty during your race

We’ve all seen it and most of us have done it … 30 minutes (or less) into a race athletes are already looking for a porta potty. Don’t let this be you!

how to avoid "runner's trots"

This article is for athletes that experience intestinal discomfort while running and have to “go” while running.