Statistics suggest many women are not getting enough exercise, with reasons ranging from harassment at the gym to having to manage childcare. However, some women are leapfrogging such obstacles to take up the iron-distance triathlon.
Three so-called "ironmums" explain the appeal of repeatedly completing one of sport's most gruelling challenges - a 2.4-mile swim, followed by a 112-mile bike ride and rounded off with a 26.2-mile run.
'The older I get, the better I want to get'
Claire Adam, 56, brands herself as the "hot flush athlete" because, she says, when she took up Ironman competitions, her menopause symptoms receded.
"I feel that doing endurance sport has helped me through the menopause," she says. "When I read about what other women have gone through, I feel very lucky."
Despite being sporty at school, Claire, from East Leake in Nottinghamshire, fell out of a regular exercise routine in her 20s - "when I discovered alcohol", she says - only returning to running as a single parent when her two children were teenagers.
"I could go out running at eight in the morning and come back at 12:00 and they were still in bed. They didn't even notice I'd gone," she says.
"I'm in awe of women with young children who do Ironman competitions. I was lucky that, when I got into it, mine were old enough to be left."
In 2016 she did Nottingham's Outlaw Half triathlon event and says she hasn't looked back since.
She completed her first Ironman in 2018 and has qualified to represent Great Britain in her age group at middle-distance European Triathlon Union (ETU) championships in Romania and Austria.
"For me, it was a massive achievement," she says. "I had a GB triathlon suit with my name on it.
"I wasn't competitive at all when I started - I just wanted to finish. But now I've had a few podiums and it's given me a buzz. The older I get, the better I want to get."
Claire works in sales and also cares for her elderly parents. Her routine, which consists of daily bike training, running and swimming that can last five to six hours at the weekends, has to fit around such commitments.
"When I start training for an event, I give them plenty of notice so they can organise friends to look after them - and my daughter helps out too," she says.
"Neither of my kids are that interested in sport at the moment but my elder daughter wrote on Facebook how proud she was of me and that really meant something."
'I have suffered with low self-esteem'
"You do suffer from guilt. There's a feeling - perhaps particularly for women - that you shouldn't be training. You should be looking after the family."
So says Sarah Myford, a single mum from Cornwall with seven children aged between 12 and 31.
Sarah says her passion for triathlons has worked wonders for her self-confidence - but alas not for her marriage, which foundered when she took up the sport.
She says women are often made to feel selfish for taking up exercise. "But it's hard for women in particular to find the time to do this sort of thing," she says. Sarah found the time by squeezing her training around her family life.
"I would get up in the summer at 4am to go cycling and try to get back before everybody got up," she says. "I trained for my first marathon with my youngest in a running buggy, up and down the Camel Trail. I nearly had him with me for the actual race in the buggy when the babysitter fell through."
She says she was never good at sport at school and dropped out of university when she started having children.
"I have suffered with low self-esteem because I didn't do particularly well at school. I was unemployed for quite a long time, then ended up with children and earned money by cleaning holiday lets."
She says it was only as her children grew up that she started running. "A friend said, 'Why don't you do a triathlon?' I said, 'I can't ride a bike'. That was 11 years ago."
Since then, Sarah has run six Ironman-distance races, and hopes to compete in the middle-distance ETU championships in Austria, where she has qualified to represent Britain in the 55-59 age group.
There have been hardships along the way, both for Sarah and her family.
"One of my sons got teased at school because of what I did," she says. "Teenagers are not used to seeing women do stuff like this. That is changing slowly, but too slowly.
"When I started doing triathlons, I suddenly found something I could do," she says. "It's given me the confidence to go back to university and do a degree in sport and health.
"It sounds like a cliché but I would never have felt able to go and study alongside a load of teenagers without the confidence triathlons have given me."
What is an Ironman event?
- IRONMAN (in capital letters) is a branded format for a triathlon competition that consists of a 2.4-mile (3.9km) swim, a 112-mile (180km) bike ride and a 26.2-mile (42km) run. The popularity of the brand means many people use it to refer to "Ironman-style" events held around the world with a similar format.
- If those distances feel a little excessive, you may wish to look into the positively gentle pace of a "half-Ironman" instead - a 1.2-mile swim, a 56-mile bike ride, and a-13.1 mile run.
- Ironman-style events are regarded by many as one of the toughest one-day sporting challenges in the world.
Source: International Triathlon Union
'It's never too late to start exercising'
Until she turned 50, Edwina Brocklesby would not have described herself as sporty at all.
"I played a bit of netball at school and did some ballroom dancing as an adult, but that was about it," she says.
"I was a full-time social worker and typical stressed-out mum with three children and, for many years, I didn't have time to do much exercise."
Eventually, a pointed comment by her husband Phil - that his wife would be incapable of "running even two or three miles" - sparked Edwina into action.
She decided to run a half-marathon in Nottingham. "I joined a tiny running group in the city and that group of runners were so, so supportive. They had one place in the London Marathon that year and they gave it to me."
When her husband Phil died, aged 54, Edwina found running - and the support of those in the club - helped her cope with the grief. "He died of cancer. It was very sudden - he was gone in about six weeks," she says.
Edwina, from Northamptonshire, threw herself into the sport and found endurance events were her forte. Now 76, she believes she is the UK's oldest Ironman triathlete and has completed 10 marathons and six Ironman competitions.
Part of the thrill for Edwina is the support she gets from other competitors. "You are all in it together," she says. "The run is almost always fun. I'm not one of the serious athletes - I finish around midnight."
Edwina's experiences led her to set up a charity called Silverfit, aimed at supporting older people to take up physical activity, and she has also written a book called Irongran - although she says her grandchildren Ben and Tilly say she should be called "mad gran".
"They say nobody they know has a grandmother like me.
"But I don't think it's ever too late to start exercising. The fact I've been able to achieve what I have proves that."