Last November, Thirst founder and CEO Mina Guli finished the 2018 TCS New York City Marathon. It was only the first of 100 marathons she pledged to run in 100 days to raise awareness about the world's water crisis. The 48-year-old, who's never had a passion for racing and even considers herself "a bad runner," ran 62 consecutive marathons, she tells CNBC Make It. Then she broke her femur. Even so, she was able to complete the 100-day challenge in a way thanks to her team, who ran the remaining 38 marathons for her and even pushed her along in a racing wheelchair. "I learned about the resilience of the human spirit, the power of determination and the capacity we all have when we are inspired to achieve something," says Guli, who's campaign took her across the globe. She ran across parts of Europe, India, China, the Middle East, Africa, Australia and South America before finishing back where she started, in New York City, on February 11, 2019. There are two keys to developing grit, the activist says. For starters, you have to have a clear purpose, or a "why": "The first thing is knowing why you're doing something, and being so passionate about it and committed to it that nothing will stand in your way."

Mina Guli and her team complete one of 100 marathons she set out to finish in 100 days Source: Thirst

It's especially helpful if your "why" is "something that's bigger than yourself," she adds. "For me, it's water." The second thing "is surrounding yourself with a tribe of people who will support you no matter what, who will lift you up when you need to be lifted and who will kick you in the backside when you need to have a kick in the backside," says Guli. "If you can put together a strong team that will help you through the tough times, all of a sudden, you'll find that, instead of having your feet tied down with lead weight, you will have wings." It's not the first time Guli has pulled off something physically extreme: In 2016, she ran 40 marathons across seven deserts on seven continents in seven weeks. In 2017, she upped the ante and completed 40 marathons in 40 days. Running marathons is "my way of representing just how big this water crisis is," says Guli, an Australian corporate-lawyer-turned-activist who founded Thirst in 2012 to educate the next generation about the importance of water conservation. Her organization collaborates with over 1,000 schools, has hundreds of volunteers teaching its education programs and has graduated more than 1 million students from its programs. "I talked to a lot of people about what it means to be committed to something and I realized that to achieve anything — especially to achieve big things — we need to be 100 percent committed to them, and so the idea came up about running 100 marathons," she says. In early 2018, the ultra-runner teamed up with Colgate, who sponsored her "#RunningDry" initiative.

To achieve anything — especially to achieve big things — we need to be 100 percent committed. Mina Guli founder and CEO of Thirst