A lot has changed since 1986 when PowerBar introduced the first carbo-rich bar for endurance athletes. Once found only in health food stores and the backpacks of mountain climbers, the now ubiquitous energy bar has become the 21st century food of choice, sold everywhere from Wal-Mart to organic cafes. And many of these products claim a variety of benefits, from providing energy enough for a marathon to meeting a woman's specific nutritional needs. With all the choices and high-powered marketing, who could blame you for wondering, "How do I know what's right for me?" Let us help.
"The crux of a pre-workout bar needs to be carbohydrates," says Tara Gidus, M.S., R.D., a sports dietitian and spokesperson for the American Dietetic Association. When eaten an hour or so before a workout or race, a carb-rich energy bar can top off carbohydrate stores called glycogen. Because glycogen is predominantly what your muscles burn for energy during moderate- to high-intensity activity, eating a pre-exercise bar means you'll have more reserves during a workout.
How many carbs should you look for? "I recommend finding a bar with 25 to 40 grams of carbohydrate and 100 to 200 calories," says Gidus. However, she cautions that a pre-workout bar should have minimal amounts of fat, protein and fiber. "These will slow down digestion, which can lead to unwelcome stomach unrest during exercise." In other words, find a bar that is predominantly quick-to-digest high-glycemic carbs such as dried fruit, cane juice or honey with no more than five grams of fat and fiber and 10 grams of protein.
What We Like
PowerBar Pria Grain Essentials Orchard Apple Cinnamon Crisp (powerbarpria.com)
160 calories, 31 grams carbs, 2 grams fat, 5 grams protein, 5 grams fiber
Kashi Chewy Granola Bar Cherry Dark Chocolate (kashi.com)
120 calories, 24 grams carbs, 2 grams fat, 5 grams protein, 4 grams fiber
Honey Stinger Apple Cinnamon with Cranberries (honeystinger.com)
180 calories, 28 grams carbs, 3 grams fat, 10 grams protein, 1 gram fiber
The Long Workout
Similar to your pick for a pre-workout bar, your choice for extra energy during long workouts (more than an hour) should be one containing roughly 70 percent of its calories from quick-digesting carbs. When you exercise past the 60-minute mark, says Kristine Clark, Ph.D., R.D., director of sports nutrition at Pennsylvania State University, the carbohydrates in an energy bar can raise your blood sugar levels and provide glycogen, sparing your body from raiding its glycogen stores in your muscles. This is an excellent way to avoid hitting the wall before crossing the finish line as well as curbing hunger during prolonged physical activity. Aim for 30 to 60 grams of carbohydrate for each hour of activity.
Clark recommends breaking bars into equal-sized pieces prior to exercise and eating the smaller chunks throughout the event. "This will prevent too much digestion from taking place at once, which can divert blood away from the working muscles," she says. Also, be sure to eat various bars during training to find one that agrees with you; trying one for the first time during a race could lead to trips to the porta-potty instead of the finish line.