LONDON - Women should not exercise for more than an hour a day in retirement if they want to live to a ripe old age, research suggests.
But the opposite is true for men: the more active they are, the better.
Researchers tracked nearly 8000 men and women for 22 years, starting from their late 60s, and monitored how physically active they were. The scientists, writing in the BMJ Journal of Epidemiology & Community Health, said the more active men were, the more likely they would live to 90.
For women, though, the benefits peaked at about an hour a day, suggesting exercise has a maximum benefit before it starts to do more harm than good.
Researchers included moderate exercise such as gardening, dog walking, DIY, cycling to work and team sports. Overall, 17% of the men and 34% of the women studied survived to the age of 90.
But the scientists, from Maastricht University Medical Centre in the Netherlands, found exercise had a big impact on the chance of reaching the milestone birthday.
Women who did 30 to 60 minutes of exercise a day were 21% more likely to survive to the age of 90 than if they did less than half an hour. When they did more than 60 minutes a day, the odds of living to 90 plateaued - and then fell. Meanwhile, men who performed more than half an hour of exercise a day were 34% more likely to reach the age of 90. But for those who exercised for more than 90 minutes a day, the chance of surviving went up 39%.
“Average life expectancy has risen over the past few decades, but has recently started to plateau in some developed nations with increasing levels of obesity and inactivity thought to be behind the trend,” said researchers.
They are not sure why gender makes a difference in the impact of exercise on longevity, but say it could be influenced by factors such as hormones, childbirth, genes and lifestyle. They also found that women who were taller than 1.75m were 31% more likely to reach 90 than women who were shorter than 1.60m.
The NHS recommends all adults get at least 150 minutes of moderate activity a week, and say exercise should come in 10-minute bursts to allow the heart rate to build up. Previous research has found only 16% of those in their 70s and 80s hit this target.