Although Mark Inglis walks on prostheses, he has achieved a feat that tests the physical boundaries of many. A few years ago, the New Zealander reached the highest point on Earth, the 8,849-metre summit of Mount Everest.
And he says that he barely needed more help than fellow mountaineers during the climb.
"I don't have a disability," emphasizes the 64-year-old in an interview with dpa. "I just have an additional complication in my training and have to concentrate much more on the mountain and make more of an effort."
He explains in an online video that he has loved mountaineering since his youth. He still had legs when he started doing it.
His great passion remained even after he suffered severe frostbite on Mount Cook in New Zealand and had to have his legs amputated below the knees.
At the time, he was trapped in an ice cave for a fortnight in bad weather.
"My family and mountaineering friends always knew that I would climb Everest," he says. "The only question was when... The mountain is like the world championship for a mountaineer."
Not many people with a disability take on this risk. According to the Himalayan Database, 26 have made it to the top - 24 men and two women - with some using helicopters.
Inglis climbed Everest in May 2006 at the age of 46 with other climbers without disabilities. "Only on the descent did I reluctantly accept help to make sure everyone got down the mountain quickly," he says. One of his colleagues died on the way down.
Inglis' wife Anne told the NZ Herald newspaper at the time: "He's going back on a sledge and the last part of the way he'll be riding a yak because he's injured his leg stumps."
Inglis later entered the Guinness Book of Records as the first double amputee to climb the world's highest mountain.
Climbing Mount Everest is expensive. A foreigner pays at least $43,000 - often twice as much, as US mountaineer and blogger Alan Arnette estimates.
This includes the fee for a permit, equipment, oxygen tanks, domestic flights, accommodation, food and a local team of helpers to guide the route, carry luggage and cook.
Inglis says that a sponsor covered most of the costs. He collected donations totalling $70,000, which were used for a rehabilitation centre in Cambodia.
Mount Everest lies on the border between the Tibet Autonomous Region in China and Nepal - the country is home to many of the world's highest mountains.
In 2017, the local Ministry of Tourism banned people with a disability from climbing peaks higher than 6,500 metres.
The reason? Concern for the safety and well-being of those affected. However, a journalist and a visually impaired mountaineer took legal action against the ban, arguing that the rule violated the human rights enshrined in the constitution.
The country's supreme court ruled in their favour - and in 2018 allowed everyone to climb the higher peaks again.
Chinese climber Zhang Hong wanted to prove something to himself - and his wife - by climbing Mount Everest in May 2021.
"After I lost my sight at the age of 21, I always wanted to do something to make my life more exciting," he says in an interview with dpa.
Zhang comes from the Chinese metropolis of Chongqing, but had long lived in Lhasa, the capital of Tibet, where he worked as a masseur.
When he started to go blind due to glaucoma, his wife married him - against the advice of other people. "I always wanted to do something to prove myself and show her that she married me without losing anything," he says.
Many people said he was crazy for his goal of reaching the world's highest summit at the age of 46, says Zhang, now 49, especially as he had no mountaineering experience at the time.
But he was inspired by American Erik Weihenmayer in 2015, who was the first blind person to climb Everest in 2001 and he wanted to do the same. Zhang scaled the 5,800-metre mountain that same year with the help of a mountain guide.
"Although I couldn't see the surroundings, the wind blew in my face and I smelled the odour of snow, but most importantly: I heard the sound of many prayer flags flapping in the wind," he reports.
Zhang faced many challenged before achieving his goal. "I had no stamina, no money, no team and no training base," he says.
To get in shape, he climbed his staircase up to the 12th floor for several hours a day with 20 to 30 kilograms of luggage and heavy mountain boots on his feet. He borrowed money for his multi-month journey and raised some of it through crowdfunding.
A film team accompanied him on his adventure. The documentary "Invisible Summit" was released in cinemas last year. The film shows the hardships of training at the base camp, tears, exhaustion and how difficult it was for his mountain guide Qiang Zi to get Zhang safely across gorges and huge masses of ice.
Just below the summit, Qiang and the cameraman were no longer able to make it, says Zhang. In his own words, he had to trust other mountain guides who spoke neither English nor Chinese.
For Inglis and Zhang, it is important to show that you can achieve a lot despite a disability - and that it all depends on the right attitude.
Zhang says that climbing Everest has made him more self-confident. He used to worry about what others thought of him.
Not any more.
