But not Sally Field, who is a passionate fundraiser, tireless volunteer and dog walker for her local RSPCA - at the age of 98.
At a time in her life when most of us would put our feet up in well-deserved retirement, Sally puts animal welfare first.
She has been volunteering at RSPCA Millbrook Animal Centre in Surrey for the last 37 years, and still takes ten of the centre's dogs for a walk twice a week - after walking her neighbour's five dogs first.
Widow Sally has also adopted many of the centre's rescued dogs herself, and currently looks after Jack Russell Rosanna, and terrier cross Whisky, who had been badly beaten.
If that were not enough, the pensioner, who worked in the fire service before retiring, also helps in the snack bar and on fundraising days, cooking and serving up teas and coffees to volunteers and supporters.
And as a long-standing member of the Centre's Friends Group, she has helped to raise thousands of pounds to help support its vital work.
She has also refused to allow health problems and a burglary to prevent her from helping animals.
Earlier this year she spent months in hospital after a knee replacement, during which time her house was broken into and sentimental jewellery and mementos stolen.
The RSPCA's Liz Wood said: "It's been a rough year for her, especially losing items that belonged to her husband, but she carried on regardless. She never moaned about her aches or pains, or the emotional pain of losing things so dear to her.
"The centre got together with her neighbours and raise money to repair the broken windows of her bungalow and replace some of the items that were stolen.
"She's an incredible lady who has devoted four decades of her life to volunteering for us, and now she comes in every Wednesday and Friday to walk the dogs, rain or shine.
"Most people who see her on our fundraising days, on her feet all day cooking or making sandwiches, can't believe she's nearly 100.
"She is always standing up for animal welfare. She's quite a feisty character who doesn't mince her words and who says what's on her mind. If she sees someone who isn't treating their animal correctly she'll go straight in there and tell them off.
"The dogs love her and wait anxiously for her to arrive, and the same goes for all the staff and other volunteers here. She really is an inspiration to everyone."
Sally spent many years caring for her husband after he returned from action in Burma during the Second World War, until he died 20 years ago - but even while she was nursing him, she carried on volunteering at the centre.
The widow, who experienced German bombing raids herself during the war, then filled her home with Corgis, her favourite breed, before she began to bring home and care for rescue dogs, many of which had been badly abused.
An inspiration to everyone who meets her, a video of Sally talking about her dog walking went viral earlier this year, watched over 10 million times in the first three days.
Sally said she walks the centre's dogs because "it's a job that has to be done. I really like doing it, I love animals and I've always been passionate about their welfare.
"I walk ten dogs a day, and five of my neighbour's dogs before that. Then I take an old lady's dog out that's got Alzheimers. If I could afford it I'd take them all home.
"I don't sit indoors watching the telly. People say I should rest more, and I say, 'are you joking?'. I don't feel any different than when I was in my 50s. I think it's all down to keeping exercised and working. Age doesn't mean anything, it's just a number.
"The kennels is my life, I always look forward to going up there. I'll never stop doing it, I'll keep going until I'm finished.
"You do it to help people, that's what we're on this earth for to help one another, isn't it?"