Sugar Shock!

Sugar, it can make you fast .... and it can make you fat! Experts argue about how much sugar active people need, but agree on one thing: We eat too much of it for our own good.

Imagine making a life-size sculpture of yourself out of sugar, then eating the entire thing over the next 365 days. That might sound gross, but many of us do roughly the equivalent every year, according to the latest figures from the United States Department of Agriculture. The average American eats 156 pounds of added sugar annually. We’re not talking about the kind you find naturally in whole foods, but sugar that’s been poured in during processing.

Not good. The American Heart Association recommends that we eat no more than six to nine teaspoons (24 to 36 grams) daily, depending on gender. But because food manufacturers dump sugar into many packaged foods—bread, crackers, soups, sauces, and ­salad ­dressings—most of us average two to three times the prescribed amount (about 22 teaspoons, or 89 grams) without even knowing it. New York Times food writer Mark Bittman recently called added sugar “the biggest public health challenge ­facing the developed world,” likening it to tobacco’s infiltration into every nook of our society in the 1950s and ’60s. Here’s what cyclists need to know about this problem.

FAST FUEL
To be clear, you need some sugar to fuel your rides. As the simplest form of carbohydrate, it’s easy to absorb and is found in whole foods in several common natural forms, including sucrose, glucose, fructose, and lactose. The process of digestion converts all sugars into glucose, which the body then stores as glycogen­ in the liver and muscles. Most of us can store only enough to get us through two hours (tops) of high-intensity­ hammering, however. So when your stores run dry, you need to pour sugar directly into the tank to keep muscles firing. Giving your muscles regular doses (30 to 60 grams an hour after the first hour) of the sweet stuff during hard efforts helps you squeeze more gains out of training because you can push harder and longer, says Michigan-based sports dietitian Donna Marlor, BSN, RD, CSSD.

After a hard effort, sugar also quickly replenishes the energy stores you’ve depleted, not only in your muscles but also in your liver and brain. In fact, your brain operates solely on sugar. It typically uses about 20 percent of the ­glucose circulating in your blood, but when you get on a bike, it demands more to keep you focused and send command signals to the rest of your body. Some experts believe that when you’re pedaling as hard as you can and start to lose steam, it’s because your neurons, not your legs, are running low on fuel. Your brain, like your muscles and liver, adapts with training to store more glycogen for your next effort.

TOO MUCH OF A GOOD THING
The problem is that the same simple sugar that gives you a boost on your bike is bad for your arteries and organs when you do a lot of sitting around. And even though cyclists are more active than people who don’t exercise, many of us spend more time at our desks (or on couches) than we do on our saddles. During inactivity, the sugar your muscles would normally sponge up forces your body to secrete insulin, the metabolic doorman that escorts free-floating sugar from your bloodstream into your cells. The doorman can work only so fast, however. And if you pour in too much sugar, the insulin starts blocking it, leaving it in your bloodstream, where it latches onto proteins and damages blood-vessel­ walls. That leads to ­inflammation, which paves the way for hardened arteries and heart disease. In the meantime, your body still pumps out insulin to try to clean up the mess and eventually converts the excess glucose into stored fat. Repeat this process over and over again, and the doorman eventually calls it quits, which means you can no longer get sugar into your cells, and that signals diabetes.

Eating a sugar bomb (a slice of cake, a doughnut) also triggers blood-sugar fluctuations and imbalances of the hormones that regulate appetite, which can lead to overeating and fat gain, especially in your belly. Some experts, most notably Joe Friel of the Training Bible series and The Paleo Diet for Athletes, caution that eating a lot of sugar in your daily diet also hinders your fat-burning metabolism both on and off the bike, so you’re less efficient in training. “Your body is very adaptive,” says Friel. “It’ll use what you give it the most of. And the more sugar that comes in, the more your body attunes to using quick energy.” That means you don’t burn fat as readily for fuel, leading to faster energy drain.

Not only does consuming excess sugar alter your fat-burning metabolism, it also changes your brain circuitry and may even be addictive. That’s right: There’s a reason you “can’t eat just one.” Sugar lights up the same reward receptors and triggers the same cascade of feel-good brain chemicals (like serotonin and dopamine) as cocaine does. So when you’re trolling for a postride cookie even though you sucked down a gel during your ride, it may not be about restocking your energy stores as much as it is about feeding your head. And because overloading on sugar messes with the chemistry in areas of the brain that control food intake, it becomes harder to regulate how much we eat. So we end up eating even more sugar and get caught in a vicious cycle.

THE SWEET SPOT
For the greatest on-bike benefits, fuel your riding by sticking to whole foods made with no added sugar. Nature delivers what you need in packages that meter out the doses in a healthy, sustained way. Fructose found naturally in fruits and vegetables is fine, for example, because the fiber in those foods slows the speed by which sugar enters your bloodstream. The protein in milk does the same for lactose, the natural sugar found in dairy.

Cut out foods with added sugar from your daily menu. The most obvious are sodas, bakery goods, and candy. But as noted earlier, you’ll also find sugar in most processed foods that come in a box, jar, carton, or can. Watch for added sugar in a multitude of names and incarnations, including beet sugar, corn sugar, corn sweetener, corn syrup, fruit juice concentrate or puree, high-fructose corn syrup, honey, malt sugar, molasses, syrup, and maple syrup. Ingredients ending in “ose” are all forms of sugar. If any of those are among the first three to five on the list, that’s too much.