Older people who lift weights in the gym will live for longer, if new scientific research is to be believed.
But they will only have lower odds of being sent to an early grave if they lift weights quickly and in moderation - and they must avoid heavy ones.
Brazilian scientists tracked the muscle power of 4,000 people aged between 40 and 85 over the course of six years to make the conclusion.
Each participant was assessed for how many times they could lift weights that were gradually getting heavier in the 'upright row' position in a certain time frame.
The upright row position involves the participant holding a weight at hip-height and lifting it up to their shoulders with elbows pointing out.
The experts at the Exercise Medicine Clinic in Rio de Janeiro said it is a common movement used in daily life, such as for picking up shopping bags.
Researchers found that at a follow-up after six-and-a-half years, 247 men - or 10 per cent - and 75 women - or six per cent - had died.
Their results, presented at a cardiology conference, showed those with the ability to lift weights at speed lived longer.
But gym-users who lifted the heaviest weights - defined as having the most muscle power -were up to 13 times more at risk of dying.
Study author Professor Claudio Gil Araújo said: 'Doctors should consider measuring muscle power and advise more power training.'
Muscles get gradually weaker as people age and it's a common contributor to death in people over 40.
The average age of the participants was 59. Five per cent were over 80, and just over two-thirds were men.
Professor Araújo said: 'Rising from a chair in old age and kicking a ball depend more on muscle power than muscle strength.
'We now show that power is strongly related to all-cause mortality.
'But the good news is that you only need to be above the median for your sex to have the best survival, with no further benefit in becoming even more powerful.'
The research team are currently examining the link between muscle power and specific causes of death including heart disease and cancer.
But the new study is the first time that muscle power has been assessed. Previous research has focused only on muscle strength, primarily using the handgrip exercise.
The researchers said the best way to increase muscle power is to choose multiple exercises for the upper and lower body.
Choose a weight that isn't too easy or hard to lift, they added, and said to do up to three sets of six to eight repetitions moving the weight as fast as possible.
The findings were presented today at EuroPrevent 2019, a congress of the European Society of Cardiology, in Lisbon, Portugal.