If you have parents in their mid-80s, a sense of inevitability and even dread can settle in. Every phone call that comes at an odd hour makes you wonder; “Is this it?”

After all, people aged 85 are sometimes known as “extreme agers” or the “oldest old” – and so it’s not unreasonable to wonder how much time they have left.

Possibly more than you expect – but it largely depends on how much time they spend out of their comfy rocker.

A new study finds that one hour of walking per week is associated with greater longevity in people aged 85 and above.

It’s a paltry amount of exercise – but it pays surprisingly big dividends,.

Compared to inactive individuals, study participants – average age 87 – who walked at least one hour per week had 40 per cent lower relative risks of all-cause mortality, and 39 per cent lower cardiovascular mortality.

How much exercise is best?

Regardless of age, adults are advised to follow those government guidelines that even youngsters tend to ignore – at least 150 minutes a week of moderate intensity activity or 75 minutes a week of vigorous intensity activity, or an equivalent combination.

That breaks down to about 21 minutes a day.

Even for someone heading into their 90s and beyond, it’s not necessarily a lot.

But, as study author Dr Moo-Nyun Jin of Inje University Sanggye Paik Hospital, Seoul, observes: people tend to become more sedentary as they age, and their physical activity levels drop.

“Adults are less likely to meet activity recommendations as they get older,” he said.

“Our study suggests that walking at least one hour every week is beneficial for people aged 85 years and older. Put simply, walk for 10 minutes every day.”

From 10 minutes a day, exercise can help you live to 100.

The study included 7047 adults aged 85 or older who underwent the Korean National Health Screening Program from 2009 to 2014.

Participants completed a questionnaire on leisure time physical activity which asked the length of time spent each week on walking at a slow pace, moderate intensity activity such as cycling and brisk walking, and vigorous intensity activity such as running.

Here’s how it broke down:

• 4051 (57.5 per cent) participants did no slow walking at all.
•  597 walked less than one hour.
• 849 walked one to two hours.
• 610 walked two to three hours.
• And 940 walked more than three hours per week.
• Only 538 participants (7.6 per cent) met the guideline recommendations for moderate-to-vigorous intensity physical activity.

The researchers analysed the associations between walking, all-cause mortality and cardiovascular mortality after adjusting for energy expended on moderate-to-vigorous intensity physical activity.

Dr Jin said that walking was linked with a lower likelihood of dying in older adults, regardless of whether or not they did any moderate-to-vigorous intensity physical activity.

Minimum amount required

“Identifying the minimum amount of exercise that can benefit the oldest old is an important goal since recommended activity levels can be difficult to achieve,” he said.

“Our study indicates that walking even just one hour every week is advantageous to those aged 85 years and older compared to being completely inactive. The take home message is to keep walking throughout life.”

That’s the good news. The bad news, if the results are an indication of the wider population, more than half of older people are doing no exercise at all – and perhaps dying earlier than they might have liked.

These results were presented last week at the European Society of Cardiology 2022 Congress in Barcelona.