The insurer’s latest Real Retirement Report found that 39 per cent of over-55s continued to receive a wage even after the traditional retirement age.
Some 23 per cent of 65 to 74 year olds were still wage earners in December 2012 - up from 18 per cent in February 2010.
The report, which draws on data from the 2011 census and interviews with 14,600 UK consumers aged over 55 between 2010 and 2012, states that a maturing generation of baby-boomers born after the Second World War will push the number of people turning 65 to 6.5m over the next decade (an increase from 5.2m over the past 10 years).
Roger Marsden, head of at-retirement at Aviva, claimed this generation was capitalising on improved healthcare and more active lifestyles to work harder in retirement and increase their wealth.
He said: “What we are seeing is the first baby-boomers setting out a new model for later life, and getting the most out of their improved physical health and the freedom to continue working for longer.
“Many people find that staying active in a job helps to keep them young at heart, with the bonus being that it boosts their earning and savings potential in the process.
“The key to making the most of this opportunity is for people to start planning for their retirement well in advance. This way, as you approach the age of 65, you have the freedom of choice about whether you continue to work or not, rather than feeling forced to carry on out of the demand to meet financial commitments.”
The report also revealed that a typical person over the age of 55 had an average income of £1444 each month, and had £14,544 in savings.
Some 44 per cent planned to use their extra time in retirement to travel more, with 37 per cent planning to spend more time with their families in retirement.