"The extreme range of challenges you face when climbing are incomparable," he explains, adding that he enjoys the purity and simplicity of these remote environments.

Over the past 18 years, Zhang has steadily climbed 26 glaciated mountains and successfully reached the North and South Poles respectively in 2005 and 2008 during expeditions on foot.

Zhang first heard about the "14+7+2" after a conversation with Wang Shi, a businessman and renowned mountaineer, when they met during an expedition in 2009.

"But I didn't make '14+7+2' my goal back then. I never thought I could climb all those peaks during my lifetime," he explains. "I just kept climbing, and gradually I climbed them one by one."

Zhang says that while he feels lucky to have achieved this, he doesn't regard it as the summit of his climbing career, and his past experiences will only serve to motivate him more in the future.

According to Zhang's colleague and director Fang Hui, Zhang's qualities, reflected in daily life and work－such as his calmness, mental toughness and modesty－are important qualities for a successful mountaineer.

"He's not burdened by any obsessions like setting records or completing set goals, and that has allowed him to stay cool and make reasonable decisions when he faces risks on the mountain," Fang says, adding that his organization has been very supportive of Zhang's passion.

"Knowing when to wait and when to give up is important. We will only have the chance to make it to the top if we stay alive," explains Zhang, who says he has witnessed many tragedies and believes that his mindset of "never risking your life for the sake of mountaineering" has helped him to survive many dangers.

He remembers being evacuated many times due to bad weather or other hazards, sometimes from within spitting distance of a mountain summit.

His friend and climbing pal Cao Jun, who has known him for nearly two decades, is impressed by Zhang's ability to focus on details. The two often train with each other and have ventured to the Antarctic together.

According to Cao, Zhang always makes detailed preparations before each climb or expedition.

"I never use the word 'conquer'. I only have reverence for nature. We can only take on the challenge when we are fully prepared," Zhang explains, adding that many accidents he learned about happened due to insufficient preparation.

After losing many mountaineering friends and experiencing four life-threatening accidents himself, Zhang says he often has fears when he thinks about the potential risks involved.

"It's a normal reaction for anyone," he says. "What I can do is to prepare the best I can each time, and try to stay cool when danger comes."

Zhang participates in many sporting activities, such as football, badminton and marathons, and also takes the time to walk to his workplace every day to keep fit. He believes that his exercise regime and self-discipline help with mountaineering, as he often needs to trek for hours on end at high altitudes in extreme cold.

During his various expeditions, Zhang has had the opportunity to meet many top mountaineers and adventurers from all around the world.

In 2015, Zhang and his international team attempted to climb Mount Annapurna on the Nepalese side of the Himalayas, which is notorious for its harsh environment. There, the team experienced firsthand the kind of strong-mindedness required to stay alive in the face of danger.

During bad weather conditions, some of the climbers found themselves cut off from the rest of the party and in a hopelessly desperate situation. But Zhang's words of encouragement and clear thinking managed to guide them out of the crisis, and they were all eventually evacuated to safer ground without loss of life. His teammates praised Zhang's cool head in later interviews.

"Instead of my personal achievements, I always feel proud to have the chance to show the other side of Chinese people－our pioneering spirit－in this special field," says Zhang, who always carries a national flag with him during his expedition programs.

As he continues to climb, Zhang has gradually expanded his interests to other adventure sports, like orienteering.

Meanwhile, Zhang likes to spend much of his spare time on charitable activities, such as sharing his own experiences to help people through difficult situations in their lives.

"There is an invisible mountain in the heart of every person. Overcoming the invisible mountain is even more difficult than climbing a real peak," he explains, adding that he hopes to inspire them with his experiences of being a mountaineer.

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