MONTREAL -- Here’s a holiday recipe for relaxation: binge-watch movies, take naps, read books.

However, you might want to limit the lethargy to a scant couple of days if you want to keep your muscle strength up and your percentage of body fat down.

New research to be presented next week at the Physiological Society’s conference in Liverpool, England, indicates taking just a short break from physical activity could be a recipe for disaster, particularly for older adults.

"The severe impact of short-term inactivity on our health is hugely important to communicate to people,” said one of the authors Juliette Norman, a doctoral student at the University of Liverpool.

It’s a unique study, according to the researchers, because it analyzed only two weeks of inactivity. The time-frame reflects natural ebbs and flows in life; when people may naturally lay low for short periods, as they recover from an illness or are at home during the holidays.

The goal was to determine how age influences musculoskeletal changes that occur after someone has been sedentary.

Researchers studied 26 young adults between 20-35 years old and 21 older adults between 54-66 years old.

After two weeks of reduced physical activity (around 1500 steps per day), researchers found the older adults had lost significant amounts of muscle and had gained a substantial percentage of body fat – particularly around their waist. The lack of physical activity also reduced bone density, increasing the risk of developing osteoporosis and breaking bones from falls.

Even though the younger group also had decreases in muscle size, muscle strength and bone mass and gained the same amount of body fat as the older adults, the 50 and 60-year olds had less muscle and more fat at the outset. So the researchers say the ageing population has more to lose – in all respects – than the younger crowd.

According to the Physiological Society, these changes can lead to chronic health conditions.

So as temperatures drop - along with your will to walk briskly around the block – you might want to find a warmer, but active way to while away your time.

"If the gym is hard to get to, people should be encouraged to just meet 10,000 steps,” says Juliette Norman, and stay as fit as possible all year round.