People over the age of 55 do an average of 726 minutes of physical activity - 12 hours, six minutes - compared with the 698 minutes done by 18 to 25-year-olds, or 11 hours and 38 minutes.
The most popular exercise activity among over-55s was walking, with 80 per cent saying they went for a regular stroll.
Housework was the second favourite activity, cited by two-thirds of those questioned, followed by gardening, which was chosen by three in five.
Younger people were most likely to pick walking and dancing as their top activities, according to the survey carried out by drugs firm GlaxoSmithKline.
The company has launched a campaign to inspire over-55s with long-term medical conditions to lead a more active lifestyle, the Daily Mail reported.
People aged 18-29 were also found to be the least health-conscious, shunning exercise, indulging in takeaways, alcohol and not eating enough fruit and vegetables.
Those in their twenties were the least likely to eat enough fruit and vegetables with more than half claiming to not eat enough healthy food.
A quarter had two takeaways a week and 15 per cent said they wanted to address their unhealthy lifestyle.