“Gym Bunnies”- Exercise Alone Won’t Lose Kilos, Study Suggests
29 Jan 2016 --- ‘Gym bunnies’ who spend hours working out in an attempt to burn calories to lose weight are wasting their time, new US research suggests. The study, published in the Current Biology journal, indicates that the body adapts to higher activity levels - changing metabolism so that fewer calories are burned.
Researchers measured the daily energy expenditure and activity levels of more than 300 men and women. Those with moderately active levels – such as a daily walk to work, and a trip to the gym twice a week – were found to burn about 200 calories more per day than those living ‘couch potato’ lifestyles.
But after a certain threshold – described by scientists as a “sweet spot” – the extra time working up a sweat made no difference to the amount of calories burned. This might explain why those who embark on gym routines in a bid to lose weight often see weight loss hit a plateau after a few months.
Lead scientist Dr Herman Pontzer, from the City University of New York, said the findings showed that exercise alone was not enough to prevent or reverse weight gain. He explored the link between activity and energy expenditure after working among a community of traditional hunter-gatherers in northern Tanzania: "The Hadza are incredibly active, walking long distances each day and doing a lot of hard physical work as part of their everyday life” he said. "Despite these high activity levels, we found that they had similar daily energy expenditures to people living more sedentary, modernized lifestyles in the United States and Europe. That was a real surprise".
The study measured the activity and food consumption of more than 300 men and women over a week. Those with moderate activity levels were found to expend the most calories- such lifestyles might involve walking or cycling to work, taking the stairs rather than the lift, and a couple of bursts of exercise, such as gym trips, during a week.
But doing more than that makes no difference.
"The most physically active people expended the same amount of calories each day as people who were only moderately active," said Dr Pontzer.
The findings reinforce the importance of diet when trying to lose weight. However, the researchers stressed that exercise had a host of benefits for maintaining health: "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. 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" Dr Pontzer concluded.
by Kerina Tull
