By Robert Preidt
A small British study finds that having breakfast before a morning workout triggers the body to burn more carbohydrates during exercise and also speeds digestion afterward.
The study included 12 healthy men who did an hour of cycling in the morning. They either had a breakfast of porridge made with milk two hours before exercise, or had breakfast after they exercised.
The researchers tested the blood glucose levels and muscle glycogen levels of the volunteers. They found that eating breakfast increased the rate at which the body burned carbohydrates during exercise, and increased the rate the body digested and metabolized food eaten after exercise, too.
"This is the first study to examine the ways in which breakfast before exercise influences our responses to meals after exercise," study co-leader Javier Gonzalez, a senior lecturer at the University of Bath, said in a school news release.
Study co-leader Rob Edinburgh is a Ph.D. student at the university. "We also found that breakfast before exercise increases carbohydrate burning during exercise, and that this carbohydrate wasn't just coming from the breakfast that was just eaten, but also from carbohydrate stored in our muscles as glycogen," he said.
"This increase in the use of muscle glycogen may explain why there was more rapid clearance of blood sugar after 'lunch' when breakfast had been consumed before exercise," Edinburgh said.
"This study suggests that, at least after a single bout of exercise, eating breakfast before exercise may 'prime' our body, ready for rapid storage of nutrition when we eat meals after exercise," he added.
The study was published Aug. 15 in the American Journal of Physiology: Endocrinology and Metabolism.
"As this study only assessed the short-term responses to breakfast and exercise, the longer-term implications of this work are unclear, and we have ongoing studies looking at whether eating breakfast before or after exercise on a regular basis influences health," Edinburgh noted.