Eating breakfast before exercise may “prime” the body to burn carbohydrates during exercise and more rapidly digest food after working out, according to a study.
Scientists studied the effect of eating breakfast versus fasting overnight before an hour’s cycling.
They also carried out a control test where breakfast was followed by three hours’ rest and volunteers ate a breakfast of porridge made with milk two hours before exercise.
Post exercise or rest, the researchers tested the blood glucose levels and muscle glycogen levels of the 12 healthy male volunteers who took part.
They discovered that eating breakfast increased the rate at which the body burned carbohydrates during exercise, as well as increasing the rate the body digested and metabolised food eaten after exercise too.
Scientists from the University of Bath worked with colleagues at the universities of Birmingham, Newcastle and Stirling to conduct the study.
Dr Javier Gonzalez, from the University of Bath, said: “This is the first study to examine the ways in which breakfast before exercise influences our responses to meals after exercise.
“We found that, compared to skipping breakfast, eating breakfast before exercise increases the speed at which we digest, absorb and metabolise carbohydrate that we may eat after exercise.”
PhD student Rob Edinburgh said: “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.
“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.
“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.”
The authors said the long-term implications were unclear and further research would have to be carried out.
Mr Edinburgh added: “We have ongoing studies looking at whether eating breakfast before or after exercise on a regular basis influences health.
“In particular there is a clear need for more research looking at the effect of what we eat before exercise on health outcomes, but with overweight participants who might be at an increased risk of Type 2 diabetes and cardiovascular disease.
“These are some of the questions we will now try to answer.”
– The study, Pre-Exercise Breakfast Ingestion versus Extended Overnight Fasting Increases Postprandial Glucose Flux after Exercise in Healthy Men, is published in The American Journal of Physiology – Endocrinology and Metabolism.