Here's something that might please those in their 50s - researchers are suggesting that 60 is the new middle age.
The claim has been made by Sergei Scherbov, the world population program deputy director at the International Institute for Applied Systems Analysis in Austria.
Dr Scherbov has been working on a study of future population projections for Europe, up to the year 2050.
The study, led by Professor Warren Sanderson, of Stony Brook University in the US, notes that if old age is fixed at a certain point, the proportion of old people will rise because of increasing life expectancy.
If the threshold for being old is moved to take into account longer lives, the proportion of old people actually falls over time.
Dr Scherbov said: "What we think of as old has changed over time, and it will need to continue changing in the future as people live longer, healthier lives."
"Someone who is 60 today, I would argue is middle aged," he said, adding that 200 years ago, a 60-year-old would be a very old person.
The study says that, with people living longer, healthier lives, age should not just be a number we reach but a reflection of the life we lead.