Even a short period of strength training could improve the long-term health of obese people, if results achieved in mice scale up to human levels.
In a paper published in the Journal of Endocrinology, scientists led by Leandro Pereira de Moura of the University of Campinas in Brazil detail the results of short-term work-outs given to obese mice.
The mice underwent strength training, but not over a long enough period that the exercise led to weight loss or change to body shape. Nevertheless, the activity led to reduced levels of fat around the liver, reduced inflammatory markers and improved blood glucose regulation.
The outcomes are promising, because obesity is linked to increased risk of non-alcoholic fatty liver disease, insolence resistance and type 2 diabetes.
“The fact that these improvements in metabolism occurred over a short time, even though the overall amount of body fat was unchanged, suggest that strength training can have positive effects on health and directly affect liver function and metabolism so may be a more effective, non-drug and low-cost strategy for improving health in obesity,” says Pereira de Moura.
The findings, while encouraging, should be viewed with caution. Previous research indicates that many, perhaps most, results obtained using mice as models fails to replicate in humans. A staggering 95% of drugs successfully tested on animals fail to reach the market once human trials begin.
It’s a point readily conceded by Pereira de Moura.
“Although these findings show a clear benefit in obese mice, to mimic strength training in animals is difficult,” he says.
“More investigation is required in both animals and people to really understand how liver metabolism is affected by strength training.”
He adds that even if the rodent results do turn out to be replicable in obese humans, “these health benefits would be even more effective if accompanied by reduction of body fat”.