Key points from article :
People doing both aerobic and muscle exercises were more likely to live longer than those who did just one, US researchers found.
The NHS advises adults over 65 to be physically active every day and do activities to improve strength, balance and flexibility at least twice a week.
It also recommends at least 150 minutes of moderate-intensity activity a week.
They asked more than 150,000 people in their 60s and 70s about their exercise routine and then followed them up.
But those who combined regular aerobic exercise with muscle-strengthening activities once or twice a week fared even better.
They had a 47% lower risk of dying from any cause, apart from cancer, over the next nine years - than those who were not active at all.
"Older adults would probably benefit from adding weightlifting exercises to their physical activity routines." said study author Dr Jessica Gorzelitz.
The study was published in the British Journal of Sports Medicine.
