CHAMPAIGN, Ill. -- After you've run that marathon, take time to eat. A post-exercise
meal containing amino acids and carbohydrates may speed your body's recovery
and enhance peak-performance levels, according to University of Illinois
In a series of studies, researchers also found that eating oat-based cereal before exercise can help fight fatigue and feelings of hunger. The pre-exercise findings, based on human studies, were published in the American Journal of Clinical Nutrition and in the Journal of Nutrition.
The post-exercise findings, involving rats, will be presented April 6-9 by U. of I. graduate students Tracy Gautsch and Josh Anthony at the American Society for Nutritional Sciences annual meeting in New Orleans.
Healthy adults consumed nothing or a cereal with oat, wheat or corn meal 90 minutes before a 90-minute low-level cycling exercise followed by a competitive 5-mile ride. Those who had eaten reported less fatigue and less hunger after the workouts. Performance levels were not affected in this study, funded by Quaker Oats Co., but initial metabolic changes suggested a pattern of improvement.
The goal of the research was to alter blood chemistry, specifically the ratio of tryptophan, an essential amino acid, to large neutral amino acids, said principal investigator Donald K. Layman, a U. of I. professor of nutrition. Tryptophan levels in the blood help regulate the release of serotonin in the brain, causing lethargy and fatigue.
"The oat-based cereal allowed us to increase the denominator in the ratio," Layman said. "Raising the level of large neutral amino acids should reduce the amount of tryptophan getting into the brain and reduce feelings of fatigue."
The oat cereal worked to reduce the rise of glucose and insulin, allowing for a stable blood chemistry that promoted the efficient use of free fatty acids, Layman said. These effects, he added, are probably derived from the soluble fiber in oats.
In the post-exercise study, funded by the National Institutes of Health, rats did exhausting running exercises, leaving them with low rates of muscle-protein synthesis and low glycogen levels. A follow-up meal of amino acids (from a high-protein liquid) and carbohydrates (a sugar solution) allowed the rats to recover to normal rates of muscle-protein synthesis in less than an hour.
Rats that were given just water didn't recover for at least eight hours; those that drank a carbohydrate solution similar to a sugar-based sports drink took at least four hours for complete recovery, although they attained 60 percent of their recovery in an hour.
"No one has really focused on the issue of post-exercise food consumption," Layman said. "If we can shorten recovery with dietary treatment after exercise, then obviously we could enhance performance with it."