"When people tell me I can't do something, I take it as a challenge," she says quietly. "Endurance sports appeal to people who have had it tough in life. After having to fight so hard as a child, I know I can use those same skills to complete a hard race."
Svendsen moved to New Zealand from Scandinavia to study in 2001 and quickly immersed herself in the adventure racing community.
She was to suffer one more blow.
"I didn't even realise I suffered from depression until I had a massive anxiety attack on the start line of the [Coast-to-Coast] Longest Day in 2012.
"Several athletes who knew me helped me get through. Then a few days later, Nat and Kristina Anglem called and said, 'we know what you're going through, and we want to help you. You cannot do this alone.'
"Somehow I clung to the hope that I could get better. I just didn't know how, as I was afraid of asking for help. My recovery took a while but I just had to fight again like I did when I was 10."
Svendsen went on to complete Godzone later that year. Next weekend, she joins an international cadre of elite adventure racers in Wanaka for Red Bull Defiance - a 160km multisport event that combines running, mountain biking, kayaking and undisclosed special stages such as abseiling and clay bird shooting.
Race director Patrick McAteer is just as excited as the competitors to be back.
"Red Bull Defiance 2014 set a benchmark for the toughest, most challenging two-person, two-day multisport endurance race in the world. True to the nature of this world-class event, 2016 retains all the challenging elements of 2014 with increased competitor numbers, new categories and evolving the special stages with a twist."
Svendsen was part of the 2014 winning women's team, and returns to race the new elite women's category with Joanna Williams, Katie Bryan and Sarah Manders.
A hefty prize purse and high-calibre competition has attracted a strong international field in the men's elite, including Australians Jarad Kohlar and James Pretto, Kiwis Sam Manson and Hamish Fleming and Swedish Team Thule members Jacob Roberts and Rickard Norlin.
The elite mixed teams race will be a tough contest, with defending champions Simone Maier and Marcel Hagener (New Zealand) duking it out with Mimi and Jacky Boisset (France), Martin Flinta and Helena Erbenova (Sweden), and South African stars Ryan Sandes and Bianca Haw.
The 2014 elite men's champion, Braden Currie, will not race this year as he maintains a firm focus on triathlon in the build-up to the Rio Olympics. Competitors will still feel Currie's presence as they race a course he designed, traversing more than 100km of private land.
Richard Ussher will be missing from the start line but not the event, as he takes his place on the 2016 organising team alongside McAteer and Mike Watkins.
Svendsen is undaunted by the stiff competition.
"We don't look at who else has entered - the pressure comes from ourselves. Jo [Williams] is an incredible athlete and an amazing friend."
Svendsen encourages others to ignore people who say you can't.
"There are many inspiring people in New Zealand who will say 'you can!' Choose to listen to their voices instead."
Red Bull Defiance
What: 160km two-day multisport
When: January 23-24
Where: Wanaka
For more information: www.redbulldefiance.co.nz
