Which Comes First, Cardio or Weights_ - Alex Hutchinson [87]
Scientists have long been puzzled about why carb-filled drinks also seem to help in shorter bouts of exercise, when energy stores shouldn’t be an issue. Researchers at the University of Birmingham published a study in 2009 showing that cyclists performed better in a time trial if they rinsed their mouth with a drink containing either glucose or a tasteless carbohydrate called maltodextrin but saw no improvement from rinsing with an artificially sweetened drink. Brain scans showed that glucose and maltodextrin made the reward centers in the subjects’ brains light up while artificial sweetener didn’t, suggesting that our mouths have previously unknown carbohydrate sensors. Sports scientists have now begun advising elite athletes to rinse and spit out sports drinks as they approach the end of grueling endurance races, when their stomachs may be unable to handle drinking anything.
• SALTS: Electrolytes, which replace the salts lost in sweat, are thought by some researchers to play a role in muscle cramping (see Chapter 3) but are more relevant to post-exercise recovery for most people. “You have to be working really, really hard for the salt to matter,” Spriet says. Gatorade makes a little-known product called GatorLytes, which is essentially a sachet of salts that you add to regular Gatorade to up its electrolyte content—but it’s available only to high-level sports teams, since typical athletes simply don’t need it.
For the average person working out at the gym for an hour or less at a time, there’s no need to drink anything other than water. If you prefer a sports drink, choose one with a smaller amount of carbohydrate (3 percent is better than 6 percent), or simply dilute a standard sports drink with water. And don’t put your faith in the magical claims of high-tech additives in some sports drinks—because beyond the three ingredients listed above the science gets a lot weaker. In fact, Gatorade’s relaunch of its product line in the United States coincided with the decision to disband its U.S. scientific advisory panel in 2009. The new line boasts specialized formulations such as vitamin C to perk you up in the morning, B vitamins to help you metabolize energy, theanine to improve focus, antioxidants to “protect your body,” and so on. Spriet is unimpressed. “Everyone wants to make things more complicated, but there’s a reason the basic formulation hasn’t changed in years,” he says. “It’s fluid, sugar, and salt. That’s all it is—and it works!”
Will taking antioxidant vitamins block the health benefits of exercise?
Every year when cold and flu season hits, sales of orange juice soar as people seek the protection of vitamin C. Faith in the power of antioxidants is deeply entrenched. But over the past few years, a series of vast studies involving hundreds of thousands of subjects has failed to find any health benefits from antioxidant supplements. Now, another group of studies suggests that popping these pills may even block some of the benefits of exercise and slow down post-workout muscle recovery. It would be premature to pronounce the end of the vitamin era on the basis of a few studies—just as premature as it was to leap on the vitamin bandwagon in the first place. But some skepticism is due. “For something like vitamin C, it’s important