Researchers at the University of California-Davis evaluated the effects of natural and commercial carbohydrate supplements have on endurance running performance.
Runners depleted their glycogen stores in an 80-minute run followed by a 5K time trial. Runners completed three randomized trials -- raisins, chews and water only -- separated by seven days.
The study, published in the Journal of the International Society of Sports Nutrition, found those who ingested raisins or sports chews ran their 5K on average 1 minute faster than those who ingested only water.
Eating raisins and sports chews promoted higher carbohydrate oxidation compared to water only, the study said.
"Raisins are a great alternative to sport chews as they also provide fiber and micronutrients, such as potassium and iron, and they do not have any added sugar, artificial flavor or colors," James Painter, nutrition research adviser for the California Raisin Marketing Board, said in a statement.