Eating
breakfast burns more carbs during exercise and accelerates metabolism for next
meal
University
of Bath
Eating
breakfast before exercise may "prime" the body to burn carbohydrates
during exercise and more rapidly digest food after working out, University of
Bath researchers have found.
Scientists from
the University's Department for Health, working with colleagues at the
universities of Birmingham, Newcastle and Stirling, were studying the effect of
eating breakfast versus fasting overnight before an hour's 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.
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.
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.
Dr Javier Gonzalez, senior lecturer in the Department of Health who co-led the study, 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."
Rob Edinburgh,
PhD student in the Department for Health who co-led the study, 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 study is
published in American
Journal of Physiology: Endocrinology and Metabolism.
An interesting
aspect of this research is that it shows that extrapolating from other studies
conducted on people who are fasted, which is common in metabolism experiments,
may not be reliable, as being fed alters metabolism.
Dr Gonzalez
added: "Whilst 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 are not fasted during the day."
Rob Edinburgh
said: "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.
"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 research was
funded by grants from The European Society for Clinical Nutrition and
Metabolism, The Rank Prize Funds, and the Medical Research Council.