The efforts of millions of people who try to keep in shape with jogging, swimming or hitting the gym have been rendered useless after scientists claimed the activities were a waste of time.
Researchers at the University of London found that nearly 20 per cent of people who follow regular aerobic exercise did not gain any significant health benefits which are determined by our genes and can vary substantially between individuals.
Principal investigator James Timmons, from the Royal Veterinary College, said other ways of keeping healthy, such as improving diet or taking medication, may work better.
"We know that low maximal oxygen consumption is a strong risk factor for premature illness and death so the tendency is for public health experts to automatically prescribe aerobic exercise to increase oxygen capacity," the Telegraph quoted Dr Timmons as saying.
"Our hope is that before too long, they will be able to target that prescription just to those who may stand a greater chance of benefiting, and prescribe more effective preventive or therapeutic measures to the others," Dr Timmons added.
The research, published in the Journal of Applied Physiology, was conducted in association with the Human Genomics Laboratory in Louisiana and the Centre for Healthy Ageing at the University of Copenhagen.