PARIS: Among covid patients, a lack of exercise is linked to more severe symptoms and a higher risk of death, according to a study covering nearly 50,000 people who were infected with the virus.

People physically inactive for at least two years before the pandemic were more likely to be hospitalised, to require intensive care, and to die, researchers reported Tuesday in the British Journal of Sports Medicine.

As a risk factor for serious Covid disease, physical inactivity was surpassed only by advanced age and a history of organ transplant, the study found.

Indeed, compared to other modifiable risk factors such as smoking, obesity or hypertension, "physical inactivity was the strongest risk factor across all outcomes," the authors concluded.

The pre-existing conditions most associated with severe Covid-19 infection are advanced age, being male, and having diabetes, obesity or cardiovascular disease.

But up to now, a sedentary lifestyle has not been included.

To see whether a lack of exercise increases the odds of severe infection, hospitalisation, admission into an intensive care unit (ICU), and death, the researchers compared these outcomes in 48,440 adults in the United States infected with Covid-19 between January and October 2020.

The average age of patients was 47, and three out of five were women. On average, their mass-body index was 31, just above the threshold for obesity.