Grip strength, the speed we walk and our ability to balance could be indicators of how long we may live, according to scientists.

The decades-long study of more than 50,000 people in 33 countries found the link between grip strength and survival could be seen in younger as well as older adults.

Other tests of physical capability, including tests of walking speed, chair-rising and standing balance, were conducted in volunteers aged 60 years and older.

More research, however, is required to determine whether these are able to predict long-term survival in younger people, in the same way as grip strength.

"Simple non-invasive assessment measures like these, that are linked to current and future health, could help doctors identify those most vulnerable to poor health in later life and who may benefit from early intervention to keep them active for longer," said Dr. Rachel Cooper from the Medical Research Council.

The paper is published in the British Medical Journal.