This column is not about losing weight or dieting. It’s about athletic performance. But it contains some surprising fat-loss information.
To start, ketone strips are an inexpensive, nonprescription testing device used by diabetics and Atkins diet followers. When wet with fresh urine, the reactive pad on each strip will change color if the pee contains ketones, signaling that the body is burning fat for energy because it has little or no carbohydrates to burn. This puts the body in a state called ketosis, the basic cause of the dreaded athletic “bonk.” Ketosis means the body is basically consuming itself for fuel to function.
Park City’s Frank Plasso—a former elite runner and now CEO of a company that operates supplement stores at commercial gyms—says, “Athletes don’t want their body to go into ketosis, because at that point, they’re starting to burn, first, stored body fat, which athletes in general don’t have that much of, and next, muscle. When you run out of carbs, if you’re very lean, you burn muscle. You don’t want to get to ketosis, because it takes a lot longer to recover, since you’ve got to build up your glycogen (stored carbohydrates) again. Glycogen is fuel for the muscles. When you run out, your muscles don’t work as efficiently.”
Glycogen, a form of sugar, is especially important for marathoners, triathletes and other endurance athletes. Plasso says, "In a marathon, the proverbial saying is, you tend to hit the wall around 20 miles. At that point, when your body runs out of glycogen, you start running less efficiently.”
Crystal Talbot is a registered nurse who owns Advanced Health Care Solutions in Salt Lake City and has extensive experience with ketone strips. Her company offers home care for diabetics, and she formerly owned a Murray health-food store that ran support groups for Atkins dieters. The Atkins diet promotes keeping the body in a continual state of ketosis to lose weight.
Talbot says a low- or no-carb diet has serious drawbacks, and athletes should not use it to “make weight.”
“It’s very hard on the kidneys,” she says. “They have to process all that protein. That’s hard on the liver, as well. Plus, in today’s economy, a no-carb diet is expensive. You have to buy ... all that meat.”
She offers testing advice: “If the strip turns dark purple, you’re in ketosis. You really have to be in the purple color to be in ketosis. People who are pink or kind of pink won’t lose weight because they weren’t yet in the fat-burning state. Purple is the magic color. But [constant ketosis] can cause long-term after-effects.” Some of those effects, she explains, include the same symptoms as a diabetic about to go into a diabetic shock: “thirst, dry skin, confusion, dry mouth.”
Athletes in a competition may wish to take a quick ketone test to see if they’re about to hit the wall. Plasso says those who know their body well “may even feel a subtle burst of energy when the body is switching over to a ketosis stage of burning fat, because the two fuel systems, carbs and fat, overlap as you’re running out of gas.” If the strip turns darker than rose pink, get some carbs in your system, quick!
Meanwhile, when it comes to weight loss and exercise, the whole fat-burning, carb-burning issue is actually surprisingly complicated. But the cold equation is still the same: It’s all about calories, notwhat your body uses for metabolic fuel. If you want to get thinner, you still have to use up more calories than you consume. The harder the effort (or physical work) your body does, the more calories it will use. Running for half an hour each day uses more calories than walking for the same amount of time. But whether they are fat or carb calories makes little difference when it comes to weight loss.