Working out on an empty stomach before breakfast could help fight off type 2 diabetes because it ‘makes the body more efficient at using insulin’, study finds
- Exercising in a fasted state helped people control their blood sugar levels more
- They are ‘insulin sensitive’, which means they are more responsive to insulin
- The opposite, ‘insulin resistant’, is a risk factor type 2 diabetes
We’re told to fuel up before hitting the treadmill.
But a workout on an empty stomach could have ‘profound’ positive effects on our health, scientist say.
A study found exercising in a fasted state helps people control their blood sugar levels more than working out post-meal.
Their body becomes efficient at using insulin, called ‘insulin sensitive’, which is generally seen as a sign of good health.
Keeping insulin in check has the potential to fight type 2 diabetes and other metabolic conditions.
A workout before breakfast could be protective against type 2 diabetes, research shows
The study at universities of Bath and Birmingham involved 30 men classified as obese or overweight who were split into two intervention groups.
For six weeks, one group ate breakfast before exercise and one after – as well as a control group. All participants ate dinner at 8pm the night before.
The breakfast was a high carbohydrate shake. The participants were also given a placebo drink before or after the exercise, depending on which group they were in.
The exercise was cycling three times a week, supervised by a researcher, lasting up to 50 minutes.
There were no rules around their diet other than the restricted times of their breakfast and dinner.
Muscles in the group who exercised before eating were more responsive to insulin than those who exercised after, a sample of muscle tissue after the intervention showed.
This means they need smaller amounts of insulin to lower blood glucose levels – called ‘insulin sensitive’.
People with low insulin sensitivity, also referred to as insulin resistance, will require larger amounts of insulin and may have diabetes.
It could also indicate problems such as high blood pressure and high cholesterol levels.
Dr Javier Gonzalez, of the University of Bath, told MailOnline: ‘If you’re more insulin sensitive less likely to develop type 2 diabetes. When insulin sensitivity starts to deteriorate, that’s the first pathway to type 2 diabetes.
‘The group who exercised before breakfast increased their ability to respond to insulin, which is all the more remarkable given that both exercise groups lost a similar amount of weight and both gained a similar amount of fitness.
‘The only difference was the timing of the food intake.
‘Our results suggest that changing the timing of when you eat in relation to when you exercise can bring about profound and positive changes to your overall health.’
Dr Gareth Wallis, of the University of Birmingham, said: ‘This work suggests that performing exercise in the overnight-fasted state can increase the health benefits of exercise for individuals, without changing the intensity, duration or perception of their effort.’
The study found the muscles of those in the fasted exercise group had more key proteins involved in transporting glucose from the bloodstream to the muscles.
They also burned double the amount of fat than the group that did so after eating, meaning they use more of their fat as fuel because their insulin levels are lower.
This did not have an effect on their weight loss, but would have profound benefits to their bodies’ use of insulin, scientists say.
Dr Javier Gonzalez, of the University of Bath, told MailOnline: ‘When we normally exercise we get an increase in fats circulating in the blood. That’s one signal for the muscle to adapt to exercise.
‘If you do exercise in the overnight fated state, you increase the number of fatty acids that go into the bloodstream.
‘This causes changes within the muscle we can’t really see [as opposed to physical muscle growth] that contribute to overall health.
‘”Burning fat” doesn’t necessarily mean weight loss because we need negative energy loss from calories for that.’
Next, the intervention will be tested in women. The study was led by Dr Rob Edinburgh as part of his PhD and was published in the Journal of Clinical Endocrinology and Metabolism.