I've never understood Gatorade. It doesn't taste good, it comes in a variety of disturbing neon colors, and the spout on the bottle is way too big, so I'm always spilling blue liquid on the front of my shirt. If I'm craving electrolytes - a wonderful marketing euphemism for those salts hidden in with the sugar - I'd rather drink a Coke and eat pork rinds or chug salt water and eat a piece of fruit.

And yet, the allure of sports drinks shows no signs of letting up. While Gatorade began as beverage for the Florida Gators football team - the seven tablespoons of sugar per serving were supposed to help replenish the carbs lost during sweat - it has since expanded into a Byzantine array of drinks tailored for different phases of the workout process. If we really want to maximize performance, then we can't just drink Gatorade while working out. We also have to drink Gatorade Prime before exertion, Gatorade Perform during and Gatorade Recover afterwards.

Needless to say, most of these claims are bullshit. But they're an interesting kind of bullshit. Because it turns out that sugary sports drinks (like Gatorade, Powerade, VitaminWater, etc.) do generate significant performance benefits. It's just that these benefits have little to do with the replenishment of lost electrolytes. And that's why we seem to get the biggest benefits from these expensive liquids when we spit them out.

Let's begin with a clever 2009 experiment conducted by scientists at the University of Birmingham, in which eight elite cyclists performed a series of time trials in the lab. The goal was to max out their levels of effort, to have the cyclists pedal as fast as possible for as long as possible.

The experiment itself consisted of two different conditions. In the first condition, the cyclists rinsed their mouth for ten seconds with a sugary sports drink before spitting it out. In the second condition, the cyclists gargled a diet drink sweetened with fake sugar instead. Although both liquids tasted about the same, only one contained calories.

Here's where things get interesting: cyclists gargling with real sugar performed significantly better than those gargling with saccharin. The differences were especially pronounced during the final time trials, with the calorie crowd consistently putting out between 3-7 percent more effort.

How could merely rinsing the mouth with Gatorade make us perform better? After all, we've been trained by decades of sports drink commercials to assume that we actually need to swallow the stuff, that the benefits depend on getting those precious electrolytes into our bloodstream. But the commercials are lying: a series of follow-up experiments demonstrated that the cyclists actually performed better when they just gargled with the sugary drink. (Apparently, having several ounces of liquid sloshing around the belly isn't ideal for intense physical activities.) Tasting energy was more important than ingesting energy.

To understand the mechanisms behind this peculiar gargling effect, the neuroscientists then had the cyclists swish around drinks made with real sugar and saccharin in a brain scanner. Although the athletes couldn’t reliably tell the difference between the two, their brain showed much higher levels of activation in reward areas, such as the nucleus accumbens and orbitofrontal cortex, when given the drink made with real sugar. According to the researchers, this is because the human mouth contains carbohydrate receptors that respond to foods independently of their taste. Once a hint of carbohydrate is detected, these receptors immediately send a sensory report to the brain, telling it to expect a lovely rush of calories. Nothing has been swallowed, but that doesn't matter: The sugar still makes us happy.

There are two lessons here. The first is that Gatorade is a waste of money. If you really want to improve performance, gargle with something that actually tastes good, since it was the activation of reward areas that allowed the cyclists to exert maximum performance.

The second lesson has to do with the variables underlying peak effort. In general, we associate high levels of effort with high levels of pain, which is why we assume that the hardest working athletes are also the most serious. These are the runners locked in a grimace, or those body builders letting out guttural grunts, or those cyclists on the Tour de France who look like they're about to cry.

But maybe that's exactly backwards. After all, the lesson of those cyclists tasting sugar water is that their endurance was improved by a fleeting sense of delight. The pleasure drowned out their pain, helping to compensate for the burning lactic acid in their legs. Even though they couldn’t explain this pleasure, it’s what allowed them to work so hard, pedaling faster than those sad souls gargling with fake sugar. While it's still unclear how levels of pleasure modulate levels of effort, the scientists endorse the “Central Governor Model,” in which bodily fatigue is registered as the total absence of enjoyment. In other words, we only know we can’t give anymore when our reward areas go silent. Instead of enjoying the physical activity, we notice every ache and pain. And then we give up.

And that is why, the next time I play pick-up basketball or go for a long run, I won't drink a bottle of gross blue Gatorade. Instead, I'll be gargling with ice cream.