Australian scientist Dr Karl Kruszelnicki shared the best time of day to exercise if you want to lose weight, revealing that those trying to shed pounds can get much better results by exercising before breakfast.
Posted in a clip on TikTokdr. Karl, 73, reviewed a 2010 University of Belgium study that compared groups on the same diet with when they exercised and found that those who did endurance work on an empty stomach had the best results.
In the now viral video, Dr. Karl revealed how one group in the study did not exercise, the other after eating and the third before eating.
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Australian famed scientist Dr Karl Kruszelnicki shared the best time of day to exercise if you want to lose weight, revealing that those trying to shed pounds can see much better results by exercising before breakfast.
All three groups increased their kilojoule intake by 30 percent and ate a 50 percent fat diet.
‘Group one did not exercise and gained three kilos, their blood chemistry was terrible,’ explains Dr Karl.
“Group two did endurance exercises four days a week after breakfast, they gained 1.4 kg and their blood chemistry was meh,” he added.
‘Group three followed the same exercise program as group two, but trained before breakfast.
“They gained 0.7 kg, the blood chemistry was normal,” he added.
“So it seems best to exercise on an empty stomach if your goal is to lose weight.”
In a clip posted to TikTok, Dr. Karl, 73, discussed a 2010 University of Belgium study that compared groups on the same diet with when they exercised, and found that those doing endurance work on an empty stomach had the best results.
The study was based on a group of 27 healthy men, with an average age of 21 years and an average body weight of 71 kilograms.
Although Dr. Karl said there was “not enough diversity” in the study, and it was a small sample size, he said it’s a good starting point for future research.
Many recent studies have shown that going to the gym on an empty stomach burns more fat, especially in the morning.
A 2017 study published in the University of Bath’s American Journal of Physiology – Endocrinology and Metabolism found that hitting the gym while sober can help burn the fat and even turn it into muscle.
Study author Dylan Thompson, of the University of Bath, said adipose tissue — commonly known as body fat — often faces competitive challenges after eating.
After eating, this tissue is busy responding to the meal and a little exercise at this point will not stimulate the same [beneficial] changes in adipose tissue’.
He added: ‘This means that fasting exercise may induce more beneficial changes in adipose tissue, and this may be beneficial for health in the long term.’
Another study in 2013 found that early risers who exercise before breakfast on an empty stomach can burn up to 20 percent more body fat.
Researchers found that those who exercised in the morning did not consume extra calories or increase their appetite during the day to compensate for their previous activity.
They also found that those who exercised in a fasted state burned nearly 20 percent more fat compared to those who had breakfast before their workout.
In 2019, a joint study by the Universities of Bath and Birmingham found that exercise in a fasted state helps people control their blood sugar levels than exercise after a meal.
Their bodies are efficient at using insulin, called “insulin sensitive,” which is generally seen as a sign of good health.
Controlling insulin can help fight type 2 diabetes and other metabolic disorders.
Although Dr. Karl said there was “not enough diversity” in the study, and it was a small sample size, he said it’s a good starting point for future research.
For six weeks, a group ate breakfast before exercise and a group after it – as well as a control group. All participants ate at 8 p.m. the night before.
Breakfast was a high carb shake. The participants were also given a placebo drink before or after the exercise, depending on which group they were in.
The group that exercised before breakfast increased their ability to respond to insulin, but both exercise groups lost a similar amount of weight and both gained a similar amount of fitness.