Nearly a quarter of adults (22%) say they rarely go for walks but more than two-thirds (68%) report a feeling of euphoria upon reaching a summit or a spectacular viewpoint, research has found.
A further eight out of 10 people (80%) said going walking makes them feel happy, with two in three people (64%) saying they wished they went walking more often.
The survey was carried out to celebrate the Great British Walk festival this weekend and as the National Trust reveals the country's top 10 secret trails that can only be accessed by foot.
Its research found that despite people saying they enjoyed walking, 17% say they never venture more than 500 metres from their car, while nearly a quarter (23%) admitted to walking less than five miles a month.
A further 19% said they walk only five to 10 miles a month, with just 7% walking more than 50 miles.
The majority of people (89%) said the best thing about the activity is simply the feeling of being in the fresh air, while nearly as many (84%) said it was the places or things they discover en route.
Nearly three-quarters (73%) said they enjoy the memories made with friends and family, with 69% revealing that walking leaves them feeling revived.
The poll found nine out of 10 (90%) agreed that the majority of children walk less now than they did as children, with more than half (58%) saying they wished their children walked more. The survey found that 70% said they would like to go on more family walks together.
And it showed that more than a quarter of people (27%) blame their own fitness as the reason they do not walk as much as they would like, while nearly a third (31%) say they would if the weather was better.
The National Trust is encouraging everyone to join in with the campaign, get out for a walk and share their photos on Twitter, Instagram and Facebook at #GBwalk this weekend.
Alex Hunt, the National Trust's lead on outdoor engagement, said: "The Great British Walk is all about celebrating the outdoors and discovering new places on foot.
"There is something magical about walking somewhere new and uncovering its story, and the Great British Walk is the perfect way to join in and discover something new.
"We hope the nation use their feet this autumn to get outdoors and explore, and then share their photos with us."
Here are the top 10 "secret discovery" walks to mark the Great British Walk festival:
1. The White Cliffs of Dover, Kent - land acquired by the National Trust last year is now open to the public for the first time.
2. The Giant's Ring henge and stone circle in Minnowburn, Northern Ireland.
3. Erddig House, near Wrexham, North Wales - a love story between two of Erddig's family servants has been brought to life in a walk taking in rarely visited parts of the estate.
4. Sizergh Castle, Cumbria - walk to a 1,600-year-old yew tree, buried deep in the woods.
5. Sparrow Dale, Sheringham Park, Norfolk - o ften overlooked by visitors to the park, Sparrow Dale is a hidden valley that is perfect for wildlife lovers.
6. Dunstanburgh Castle, near Alnwick, Northumberland - few people venture around the back of the castle to see the breathtaking views
7. Malham Waterfall, Yorkshire Dales - a path leads to a waterfall with a hidden cave that local legend says is home to the Queen of the Fairies.
8. Trelissick, Cornwall - a walk o verlooking the Fal estuary leads hikers much further into the estate than many usually venture to a secluded, iron-age fort.
9. Stowe House, Buckinghamshire - it is possible to e xplore never-before-seen parts of the Stowe estate, including a secret garden hidden for many years surrounded by monuments and waterfalls.
10. Attingham, Shropshire - a path, newly opened up for the Great British Walk, allows visitors to share a rare view of the front of Attingham House previously only reserved for guests of the owners, the Berwick family.
The National Trust used the independent online research company FlyResearch to carry out the survey of 1,016 adults earlier this month.