Outside Magazine, January 2012
Monday, December 12, 2011 11

Myth #9: Fructose is a performance killer

Truth: Fructose can be a performance superfuel

By: Photographer: Inga Hendrickson
Athletes should embrace fructose.

Athletes should embrace fructose.    Photographer: Inga Hendrickson

The warnings are stern: avoid fructose, ­especially in the form of high-fructose corn syrup, because it’s contributing to an obesity epidemic. And the evidence is strong that people who are sedentary should avoid it. But for active individuals, it’s a different story. “All athletes who compete or train for a period longer than 45 to 60 minutes will improve their performance by ­ingesting a ­solution containing carbohydrates,” or sugar, says Luc van Loon, a professor in the Department of Human Movement Sciences at Maastricht University Medical Centre in the Netherlands. And you’ll get more performance bang if that ­sugar is, in part, fructose. When cyclists in a British study drank a beverage containing both fructose and glucose (a simple sugar that typically appears on ­labels as maltodextrin), they rode almost 8 percent faster during a time trial than riders who drank fluids with glucose alone. “Fructose and glucose are ­taken up in the intestine by different transport proteins,” van Loon says. “This allows for a more rapid uptake of carbo­hydrates from the gut.” Which means you have more calories available to you more quickly if you drink or eat carbo­hydrates containing fructose.

Most high-fructose corn syrup contains approximately equal portions of glucose and fructose and is perfectly acceptable for athletes. The concerns about high-fructose corn syrup have more to do with the highly processed foods they often show up in ­rather than the intrinsic characteristics of the ­sugar. The drawback for endurance athletes is that the ideal ratio of glucose to fructose is 2:1 (not the 1:1 of corn syrups). “There are very few drinks on the market that provide that perfect mix,” says Asker Jeukendrup, a professor of exercise metabolism at the University of Birmingham in England, who led the study of cyclists.

Get over it: Read labels. Some drinks, such as PowerBar’s Ironman Performance beverages, tout their 2:1 glucose-fructose mix. For do-it-yourselfers, sports nutritionist Nancy Clark’s homemade sports drink, from the fourth edition of her Sports Nutrition Guidebook, is an ideal performance boost. Gather ­together these ingredients:

1/4 cup sugar
1/4 teaspoon salt
1/4 cup orange juice
2 tablespoons lemon juice

Then, in a quart pitcher, dissolve the sugar and salt in ¼ cup hot water. Add the orange and lemon juice and 3½ cups cold water.

More at Outside

Comments

11
Andrew

To say that high fructose corn syrup is okay for anyone is down right incorrect. A little institution known as Princeton University conducted a study where they fed genetically identical rat groups sucrose (table sugar), and the other high fructose corn syrup along with equal amounts of rat chow. The results are undeniable, the HFCS fed rats became obese, and exhibited early type 2 diabetes, among other problems. The sucrose fed rats were nearly identical to the control group. Food for thought.

Flag This
JOHN

you are not a rat

Flag This
JOHN

you are not a rat

Flag This
Joe

You are not a rat

Flag This
Don

The article doesn't say corn syrup is okay for anyone. In fact it acknowledges that sedentary people should avoid it.

Flag This
Don

The article doesn't say corn syrup is okay for anyone. In fact it acknowledges that sedentary people should avoid it.

Flag This
You have all the same organs as a rat

To say that high fructose corn syrup is okay for anyone is down right incorrect. A little institution known as Princeton University conducted a study where they fed genetically identical rat groups sucrose (table sugar), and the other high fructose corn syrup along with equal amounts of rat chow. The results are undeniable, the HFCS fed rats became obese, and exhibited early type 2 diabetes, among other problems. The sucrose fed rats were nearly identical to the control group. Food for thought.

Flag This
You have all the same organs as a rat

To say that high fructose corn syrup is okay for anyone is down right incorrect. A little institution known as Princeton University conducted a study where they fed genetically identical rat groups sucrose (table sugar), and the other high fructose corn syrup along with equal amounts of rat chow. The results are undeniable, the HFCS fed rats became obese, and exhibited early type 2 diabetes, among other problems. The sucrose fed rats were nearly identical to the control group. Food for thought.

Flag This
Anonymous

"High Fructose Corn syrup" ISN'T the same as fructose (fruit sugars - and its inverse "levulose" is found in honey..) - corn syrup is a mixture of glucose, sucrose, maltose and fructose. "High fructose" corn syrup simply has much higher proportion of fructose in that mix, due to it's manufacturing process. Corn syrup of any type is a polysaccharide manufactured gunk which will only flag your system up in the long run - pity so much of tat rubbish has found its way int processed foods these days.. IF you ingest fruit, fruit juices or honey, you're eating fructose...

Flag This
David

*sigh* ALL rats used in testing are sedentary to the point of being the equivalent of couch potatoes. This article was about athletes -- not couch potatoes.

Flag This
BIG DADDY

So when do u drink this homemade sports drink? B4, during or after your race? If B4...how long B4 the race starts....30 minutes?

Flag This

Post Comment

Current Issue Outside Magazine

Subscribe and get a great deal! 2 FREE Buyer's Guides plus a FREE GoLite Sport Bottle. Monthly delivery of Outside - your ultimate resource for today's active lifestyle. All that and BIG SAVINGS!

Free Newsletter

Get our e-mail dispatch, with Outside articles & online exclusives, delivered to your inbox each week.

Ask a Question

Our gear experts await your outdoor-gear-related questions. Go ahead, ask them anything.

* We might edit your question for length or clarity. If it's not about gear, we'll just ignore it.