It’s that the time of the year when many people across the world overindulge in seasonal and festive delicacies and commit themselves to setting their bodies right in the New Year. At the heart of resolutions is a fresh gym membership and an intensive exercise regime that promises to deliver results in a short time. Despite best efforts, however, this approach doesn’t work for everyone — why is that? Why is intensive exercise not the most efficient way for some people to lose weight?
A study this year, using data from the IAEA’s Doubly Labelled Water Database, reveals insights on the effectiveness of exercise in spurring weight loss. The results aren’t as straightforward as you may think.
“When enrolled into exercise programmes for weight loss, most people lose a little weight, some individuals lose lots, but a few unlucky individuals actually gain weight,” John Speakman, professor at Shenzhen Institute of Advanced Technology and University of Aberdeen told the MailOnline. He’s the chair of the IAEA's Doubly Labelled Water Database Management Group and one of the authors of a study confirming what many of those seeking to lose weight have long suspected, that the calories shown burned on a treadmill’s display does not reflect the reality of the calories burned in your body.
According to the study published in Current Biology, in individuals with a normal body mass index (between 18.5 and 24.9) the body will offset the calories burned performing exercise by 28 per cent — meaning just 72 per cent of the calories will be lost over the course of the day. With age and weight, however, this ratio gets even worse, and those with the highest body mass index will only lose 51 per cent of the calories burned in exercise. The study confirms that individuals differ in the way their bodies budget energy use, and people living with obesity may have difficulty losing weight as their bodies are efficient at hanging onto their fat storage.
“There are many health benefits that can be gained by being more active and exercising, but relying on exercise alone will not help you lose weight,” said Alexia Alford, an IAEA nutrition specialist and co-author. Guidelines for weight loss do not take into account the reduction of calories burned in other life functions as the body compensates for the calories burned during exercise.
“If you increase your activity your body will compensate for it in other areas and cut back in the calories burned in breathing, digesting, fidgeting, and in general body maintenance and function. This can actually add up to quite a lot,” she explained. Alford advises to not rely on exercise alone to lose weight, but to pursue a more balanced lifestyle in all aspects and that diet is key to maintaining a calorific deficit for weight loss. Her guidance, and the conclusions of the study, come from data obtained through a nuclear technique involving doubly labelled water (DLW) and were made possible thanks to an IAEA database.
There are many health benefits that can be gained by being more active and exercising, but relying on exercise alone will not help you lose weight.
