It’s the age old debate: What time of day is best to work out?
But now an intriguing new study seems to have answered this question.
Researchers in Spain found that those who worked out at 6pm — doing running, cycling or another activity — had lower blood sugar than those who exercised in the morning.
The scientists argued that this suggested that late exercisers had both a more active metabolism and were better able to resist hunger pangs.
This meant they would both burn more calories during the day and consume less energy, they suggested.
Researchers in Spain found those who worked out at 6pm — doing running, cycling or another activity — had lower blood sugar levels than sedentary people
Normally, muscle cells become less able to absorb blood sugar in the evenings, research suggests — because insulin drops at this time.
But exercise in the evening boosts insulin levels, making it easier for cells to absorb sugar from the bloodstream and burn it for energy.
For the study, researchers tracked 186 40-something Spanish adults for two weeks, most of who were obese.
Each participant wore an accelerometer to track exercise and a continuous blood glucose monitor to track blood sugar.
Exercise times were split into morning — 6am to 12pm, afternoon — 12pm to 6pm — or evening — 6pm to 12am.
Researchers then compared blood sugar levels among sedentary participants, who did not exercise for a day, to those who had exercised at the different times.
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Dr Antonio Clavero-Jimeno, a sports scientist at the University of Granada in Spain, and others wrote in the study: ‘[Exercise] during the evening appears to have a beneficial effect on [blood sugar] in sedentary adults with obesity.’
The study was only carried out in obese and overweight people, meaning it is unclear whether the results apply to those of a healthy weight.
But it follows in the footsteps of other studies that have suggested evening exercise is best for weight loss.
One study from the University of Sydney, Australia, found that obese people who exercised after 6pm had an about 36 percent lower risk of heart disease.
Among those who exercised before this time, the benefit was only half as high — or being 17 percent less likely to develop the condition.
Another paper from Germany carried out in 2022 and involving 5,000 overweight or obese people also found that those who exercised in the evening had an up to 25 percent reduction in insulin resistance.
A handful of weight loss studies have suggested that working out in the morning is best for weight loss.
These have been based on data showing those who exercise at this time tend to be thinner than those in the evening.
But these do not account for other factors, such as more health conscious people are more likely to start off their day with a workout.
Any amount of exercise at any time of day can prompt weight loss in obese people, so long as they are not eating excess calories, doctors say.
The World Health Organization (WHO) says everyone should exercise for at least 150 minutes every week.