While many in their 80s and 90s may be starting to take it easy, 85-year old track star Irene Obera is at the other end of the spectrum.
Setting multiple world athletics records in her age category, she is one of a growing band of "master athletes" who represent the extreme end of what is physically possible later in life.
Another is John Starbrook, who at 87 became the oldest runner to complete the 2018 marathon.
Studies suggest regular exercise is more effective than any drug yet invented to prevent conditions facing older people, such as muscle loss.
To reap the full benefits, this pattern of behaviour should be laid down in a person's teens and early 20s.
Studying master athletes - sportspeople aged 35 and over - gives us an idea of what is physically possible as we age.
Analysing the world record performance times of each age group unsurprisingly reveals that physical ability does ultimately diminish, the older you get - but doesn't fall off rapidly until after the age of 70.
It is reasonable to assume these top athletes have a healthy lifestyle in general; as well as exercising, they follow a balanced diet and don't smoke or drink heavily.
Read the remainder of this article @bbc.com
Comments will be approved before showing up.