Morning workout: Speed up your metabolism with breakfast, study suggests

15 Aug 2018 --- Eating breakfast before exercise may “prime” the body to burn carbohydrates during exercise and more rapidly digest, absorb and metabolize food after working out, University of Bath researchers have shown in a study published in American Journal of Physiology: Endocrinology and Metabolism.

“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,” says Dr. Javier Gonzalez, Senior Lecturer in the Department of Health who co-led the study.

“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 metabolize carbohydrate that we may eat after exercise,” he adds.

The researchers were studying the effect of eating breakfast versus fasting overnight before an hour of cycling. In a control test, breakfast was followed by three hours' rest. The 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.

The results indicated that eating breakfast increased the rate at which the body burned carbohydrates during exercise, as well as increasing the rate the body digested and metabolized food eaten after exercise.

An interesting aspect of this research is that it shows that extrapolating from other studies conducted on people who have fasted, which is common in metabolism experiments, may not be reliable as being fed alters metabolism, the researchers note.

Dr. Gonzalez adds: “While fasting prior to laboratory trials is common in order to control for baseline metabolic status, these conditions may preclude the application of findings to situations most representative of daily living because most people do not fast during the day.”

Regarding future studies, the co-author of the study Rob Edinburgh adds that this study only assessed the short-term responses to breakfast and exercise. Meaning, the longer-term implications of this work are unclear. However, they do 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,” Edinburgh concludes.