Why working out harder doesn’t give you a licence to pig out afterwards

Our bodies adjust to higher levels of physical exercise by using energy more efficiently, so while hitting the gym is good for your health it doesn’t mean you can eat more, researchers find

PUBLISHED : Friday, 29 January, 2016, 10:56am
UPDATED : Friday, 29 January, 2016, 12:22pm

Think by working out more you can eat more? Think again.

Our bodies actually adapt to higher activity levels – so we don’t necessarily burn extra calories even if we exercise more, according to a new study by researchers published in the journal Current Biology.

“There is tons of evidence that exercise is important for keeping our bodies and minds healthy, and this work does nothing to change that message,” says researcher Herman Pontzer from the City University of New York

“What our work adds is that we also need to focus on diet, particularly when it comes to managing our weight and preventing or reversing unhealthy weight gain.”

Pontzer and colleagues measured the daily energy expenditure and activity levels of more than 300 men and women over the course of a week.

They found a weak but measurable effect of physical activity on daily energy expenditure. But further analysis showed that this pattern only held among subjects on the lower half of the physical activity spectrum.

People with moderate activity levels had somewhat higher daily energy expenditures – about 200 calories higher – than the most sedentary people.

But people who fell above moderate activity levels saw no effect of their extra work in terms of energy expenditure.

“The most physically active people expended the same amount of calories each day as people who were only moderately active,” Pontzer says.

Regular caffeine consumption does not result in extra heartbeats, study shows

Contrary to current clinical belief, regular caffeine consumption does not lead to extra heartbeats – which, while common, can lead in rare cases to heart problems and strokes which can be fatal – according to scientists at University of California, San Francisco.

The researchers analysed 1,388 randomly selected participants from the US National Heart, Lung, and Blood Institute Cardiovascular Health Study database of nearly 6,000 patients, excluding those with persistent extra heartbeats.

They were given a baseline food frequency assessment and 24-hour ambulatory electrocardiography monitoring. Frequencies of habitual coffee, tea and chocolate consumption were determined through a survey.

Of the total participants, 840 (61 per cent) consumed more than one caffeinated product daily. The researchers found no differences in the number abnormal heartbeats per hour across levels of coffee, tea and chocolate consumption.

More frequent consumption of these products was not associated with extra heartbeats.

Social media use in young adults linked to sleep disturbance

Young adults who spend a lot of time on social media during the day or check sites frequently throughout the week are more likely to suffer sleep disturbances than their peers who use social media less, according to new research from the University of Pittsburgh School of Medicine.

“This is one of the first pieces of evidence that social media use really can impact your sleep,” said lead author Dr Jessica Levenson.

“And it uniquely examines the association between social media use and sleep among young adults who are, arguably, the first generation to grow up with social media.”

In 2014, Levenson and her colleagues sampled 1,788 US adults aged 19 to 32, using questionnaires to determine social media use and an established measurement system to assess sleep disturbances.

On average, the participants used social media a total of 61 minutes per day and visited various social media accounts 30 times per week.

The assessment showed that nearly 30 per cent of the participants had high levels of sleep disturbance.

The participants who reported most frequently checking social media throughout the week had three times the likelihood of sleep disturbances, compared with those who checked least frequently. And participants who spent the most total time on social media throughout the day had twice the risk of sleep disturbance, compared to peers who spent less time on social media.