Academics found that a combination of weightlifting and aerobic exercise every week reaped the most benefits.

While most physical activity recommendations urge people to take part in muscle-strengthening exercises, few studies have specifically looked at the importance of weightlifting and early-death risk.

So researchers, led by academics at the US's National Cancer Institute in Rockville, Maryland, examined data on almost 100,000 adults taking part in a US screening study.

Participants, who had an average age of 71, gave information on their weightlifting activity and told researchers about any other exercise they took part in.

Some 23 per cent reported any weightlifting activity and 16 per cent reported regularly weightlifting at least one to six times per week.

Almost a third (32 per cent) were deemed to be "sufficiently active" by researchers, with 24 per cent meeting aerobic activity guidelines and eight per cent exceeding them.

During the follow-up period of 9.6 years, there were 28,477 deaths.

The study, published in the British Journal of Sports Medicine, found that adults who reported any weightlifting had a nine per cent lower "all-cause mortality risk".

A similar observation was made for heart disease deaths but no link was found between weight-training and cancer deaths.

Those who took part in "regular" weightlifting were found to have a 14 per cent lower risk of death.

Those who met the aerobic activity levels had a 32 per cent lower risk of death.

Adults who reported meeting the aerobic activity guidelines and weightlifting at least one or two times every week were found to have a 41 per cent to 47 per cent lower risk of death.

"Weightlifting in older adults was independently associated with lower all-cause and cardiovascular disease mortality," the authors wrote.

"The weightlifting-associated mortality benefit shown here provides initial evidence to clinicians and other health professionals that older adults would probably benefit from adding weightlifting exercises to their physical activity routines."

Adults are urged to take part in at least 150 minutes of moderate intensity activity a week or 75 minutes of vigorous intensity activity.

They are also encouraged to do "strengthening activities" that work on the legs, hips, back, abdomen, chest, shoulders and arms, at least two days a week.

Australian Associated Press