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Test Gym
Carbo-Loading is Dead. Long Live Carbs!
What the science now says about housing pasta for peak athletic performance
Test Gym is a new Elemental column about the science of exercise.
When I was a high school cross-country runner a few decades ago, my team would gather for dinner the night before meets to load up on pasta and bread. We were taught that “carbo-loading,” as this pre-race feasting on carbohydrate-rich foods was called, would help us perform our best the following day.
The concept of carbo-loading arose from research done in the 1960s by Scandinavian scientists using needle biopsies to peek at what was happening in muscles. In this study, which made a splash after it was published in Nature in 1966, researchers Jonas Bergström and Eric Hultman used themselves as the sole test subjects to measure what happened to the stores of glycogen (sugar used to fuel exercise) in their leg muscles before and after an intense one-legged session on a cycling ergometer.
They found that immediately after the bout of hard exercise, muscle glycogen levels plummeted in the leg that had done the work, while glycogen levels in the other leg remained stable. Over the next three days, the men ate a high-carbohydrate diet and the glycogen levels in their exercised…
