The researchers say their findings show the importance of encouraging people of all abilities to be active through life.
Previous research suggests the better our physical performance in middle age, the more likely we are to retain our independence and cope with everyday activities in old age, such as carrying our shopping and getting dressed.
Researchers who study this area usually employ a number of tests - such as handgrip strength, balance, chair rises, jumping height (a measure of leg strength), and back strength - when measuring physical performance.
