It came on the heels of her marriage breaking up, and after returning to an empty home she was preparing to sell, she was overwhelmed by her emotions.
"I went from this full-on environment; avalanches breaking above my head, jumping across crevasses where you might die if you fell in… to coming back here, to a property I was potentially selling because I needed to move on with my life," she told the Telegraph. "I didn't really have security in where I was living, what I was doing next, the whole divorce, how I was feeling about that. It just overwhelmed me."
Pendleton has been open about struggles with mental health in the past, but said this was on another level. After being prescribed antidepressants, tranquilisers and sleeping tablets, she was told it would start to get better after two weeks.
"I said to them: 'Honestly, if I keep taking this for two weeks I won't be here.' Because there were mornings I woke up and I thought: 'I don't want to see the end of the day.' I was a zombie. Emotionless."
It was a morning around late May-early June that triggered real worry for Pendleton. Feeling helpless and not wanting to see the next day, she rang British Cycling psychiatrist Steve Peters.
"It was the one bit of sanity in the whole process," she said. "I'm so grateful that he picked up. Because I don't think I would be here if he hadn't."
Peters contacted Pendleton's twin sister Alex, who went over and confiscated the pills. It was arranged that Pendleton would move in with her mother, where she spent June and July going through the motions.
She told the Telegraph during that time she had ups and downs, and in her low periods fantasised about how she might take her life.
"All kinds of things - whether I'd hang myself, slit my wrists… It sounds melodramatic. But I can honestly say from the bottom of my heart that I was like minutes away from calling it a day."
It was a surfing trip to Costa Rica that saw things change for the better for Pendleton, after a friend suggested to go and stay with someone she knew who ran a B&B and surf school. It was against the recommendations of just about everyone, but she took herself on a trip.
She was taken out for a surf every day on her trip, and said she came back from her trip feeling 50 per cent better. She has since become a patron of the Wave Project - a UK organisation which uses surfing as therapy.
"There is something very healing about being on, or in the ocean. The way I felt when I came back [from Costa Rica] was like: 'This is way better than any of the drugs I was prescribed'."
Where to get help:
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youthline: 0800 376 633
• Kidsline: 0800 543 754 (available 24/7)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• Depression helpline: 0800 111 757 (available 24/7)
If it is an emergency and you feel like you or someone else is at risk, call 111.
