NEW YORK: While pounding the treadmill and pumping iron will initially reduce your spare tire, the effect of exercise reduces over time as your body gets used to the strain.
“Its a surprise”, said lead author Herman Pontzer, of the department of anthropology at City University of NY.
However, those who passed the spot of twice a week were actually passing the threshold of productivity.
Pontzer succinctly summarizes their findings when he notes that the “most physically active people expended the same amount of calories each day as people who were only moderately active”. On the other hand, those with above moderate activity levels had no effect of the extra work on energy expenditure.
Those with moderately active lifestyles were found to shed just as many calories as those hitting the gym all week long.
“Too little, and we’re unhealthy, but too much and the body makes big adjustments in order to adapt”, he said. So simply adding another mile to our run or squeezing in another spin class won’t help us lose more weight.
During the study, individuals classed as having moderately active lifestyles were found to burn around 200 more calories each day than most sedentary people. That contradicts the previous understanding of how activity and energy expenditure are directly linked. Their bodies have adapted to the new routine and were burning much fewer calories than they did before.
The researchers measured the daily energy expenditure and activity levels of more than 332 adults drawn from five countries across Africa and North America over the course of a week.
“As we move from moderate activity levels up to more and more activity, our bodies adapt, so that energy expenditure per day stays basically the same even as we’re more and more active”, Pontzer said.
For future study, the researchers plan to investigate how the body responds to activity level changes.
“I see patients training for a marathon and they ask me, ‘Why am I not losing weight?’ ” even though they are exercising more and eating the same number of calories, Lofton said.
“The reality is, exercise by itself is not great for weight loss”, said Dr. Timothy Church, a professor of preventative medicine at Pennington Bio-medical Research Center, in Baton Rouge, LA. “Burning a few hundred calories through exercise and reducing caloric intake by a few hundred each day will lead to one to two pounds of weight lost per week-a realistic and sustainable goal”. Just one of them separated won’t be of much help.
The scientists use the example of the Hadza, a group of traditional hunter gatherers in Tanzania. While physical activity did have some influence on daily energy expenditure, it only made a significant difference to people who were previously sedentary. Pontzer joined up with Amy Luke at Loyola University Chicago and her team, which carried out all the measurements for the current study, to get a better idea what was going.
Neo Monitoring Desk