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JoAnna Lou
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The Restorative Effect of Sugar
Study looks at sugar, self-control and performance

We ask a lot of our dogs. We ask them to resist food on the counter, to stay inside when the front door is open and to be quiet when dogs are barking next door. With my new puppy, I’ve been thinking a lot about self-control, which is the foundation for everything from household manners to agility skills.

In humans, research has shown that there’s a relationship between the brain’s glucose supply and self-discipline. A recent study found that this is true for dogs too.

The experiment, published in this month’s Psychological Science, looked at the length of time a dog worked at an impossible task.

In the study, some of the dogs were put in a sit-stay for 10 minutes to “deplete their fuel reserves” and the rest of the dogs were put in a crate for 10 minutes. The dogs were then given a treat dispensing toy, known as a Tug-a-Jug, altered to make it impossible to get the food out.

The dogs who exerted self-control in the sit-stay gave up after less than a minute, as opposed to the crated pups who gave up after over two minutes. 

The scientists hypothesized that the self-control needed for the sit-stay depleted the dogs’ blood sugar supply, weakening their ability to exert “goal-directed effort.”

To test this theory, the scientists repeated the experiment with one difference. Half of the dogs performing the sit-stay got a sugar drink before going on to the Tug-a-Jug task. As a control, the other half got an artificially sweetened drink.

Amazingly, the sit-stay dogs that got the sugar drink performed just as long as the crated dogs. The pups who got the artificially sweetened drink showed no improvement.

Most of us will probably never give our dogs a performance-enhancing drink, but it’s interesting to know how taxing the behaviors are that we ask of our dogs. When I’m training, I usually alternate between practicing impulse control and playing games like tugging. Now I see why it’s so important to keep training sessions short and fun! 

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JoAnna Lou is a New York City-based researcher, writer and agility enthusiast.
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Submitted by Poosahkie | April 28 2011 |

It seems there would be a correlation between a sugared food and maintaining a working dog's time on task. So, would this be true - the dogs that work only for a tug/toy are not as focused or as reliable to time on task as in comparison to those dogs who work for food? Have any studies been performed with this group of dogs?

Submitted by Lisa | April 28 2011 |

I have a hunch it works the same with humans. Perhaps the best way to control that groper on the subway is to give them a candy bar and then put them in a crate for a couple of hours!

Submitted by Kay S. | April 28 2011 |

My dog would say that the tug-a-jug is always rigged to make it impossible to get food out. LOL. After a handful of attempts on different days she was never successful. Eventually she lost interest in trying at all. We went back to her busy buddy and she is much happier. The tug-a-jug went into the yard sale pile.

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