Halifax, Nova Scotia · November 10, 2026
Dr. Darren Burke, PhD, co-founder of Headstrong, has shared for the first time the story of why he gave up a tenured professorship at St. Francis Xavier University (StFX) to build the supplement brand Rivalus, and the moment at a grocery store checkout that made the decision for him.
The account first appeared in The Brain-First Brief, Dr. Burke's weekly newsletter on science, entrepreneurship and mentoring. In it, he describes going from what academics call the ultimate job security to almost three years without a paycheck.
Tenure, and the joke about "Full Retirement"
Dr. Burke had tenure at StFX and had just been promoted from Assistant to Associate Professor. Full Professor, the highest pay an academic can reach, was only a few years away.
"Most academics joke that 'Full Professor' really means 'Full Retirement,'" he said.
He is clear that he loved the job. He ran a large lab with state-of-the-art equipment, significant external funding, industry partners from around the world and a team of graduate students doing advanced research. "I'd encourage anyone to consider academia," he said.
His research caught the attention of several large sports nutrition companies, leading to funded product development and clinical trial projects. That work sparked his interest in how science could grow a business. At the same time, athletes kept asking him the same question: "Hey Doc, what supplements should I be taking?" He didn't have an answer he fully trusted, so he built his own brand, Rivalus.
Science first, packaging last
"I knew nothing about business," Dr. Burke said. He focused on what was inside each product: the best suppliers and the right dosages. Then he put it in stock bottles with plain labels.
A buyer later told him that most competitors did the reverse, spending little on ingredients and a lot on packaging. Rivalus changed its packaging several times in the early years before getting it right.
"Great product isn't enough if nobody picks it up," he said.
 Before: great inside, forgettable outside. |
 After: Dr. Burke in store with the redesigned packaging. |
The day three cards got declined
The turning point came while he was still teaching. Rivalus's largest retail partner was late paying, and his university salary couldn't cover growing inventory costs and household bills at the same time.
"My credit card got declined at the grocery store. So I tried my second card. Declined. Then my debit card. Declined," he said. "My kids were really young. We needed food and diapers, and I couldn't pay."
He borrowed money to cover the gap for 60 days, and the family nearly lost their house.
Going all in
Dr. Burke had been running Rivalus on the side, missing classes for trade shows and sales calls and spending less time with his students. After surviving that cash crunch, he decided he could no longer do both halfway.
"That's when I knew I couldn't keep doing both halfway," he said. He resigned his tenured position at StFX to focus on Rivalus full time.
His department chair was sad but supportive. Colleagues had what he calls a love-hate reaction. "Many academics secretly wish they could try business too," he said.
For almost three years he took no salary, reinvesting every dollar into the company. The breakthrough came when Rivalus's retail partner asked the brand to fill displays nationwide with its new packaging as part of a promotion. "That changed the company forever," he said.
Rivalus, now RivalNutrition, went on to become the first supplement brand made for athletes in drug-tested sport, and Dr. Burke later exited the business. Today he is co-founder of Headstrong, a brain-first sports nutrition brand whose products are NSF Certified for Sport.
Advice for anyone in a safe job
Dr. Burke's advice to anyone weighing a similar leap is practical: "Keep your day job while you build your side hustle, until you hit a breaking point where something has to change."
He says he has no regrets. "Make decisions with the information you have, take risks, and make new decisions when you need to. Live, and to the fullest."
About Dr. Darren Burke
Dr. Darren Burke holds a PhD in Exercise Physiology and Sport and Exercise Science and was a tenured faculty researcher at St. Francis Xavier University. A former national champion in flatwater canoe, he founded Rivalus, built it from a bootstrapped startup to a successful exit, and is now co-founder of Headstrong, based in Halifax, Nova Scotia. He also mentors pro athletes who are building businesses. Read more about his work with athlete entrepreneurs and why he built Headstrong.
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Frequently asked questions
Who is Dr. Darren Burke?
Dr. Darren Burke, PhD, is a sport scientist and entrepreneur based in Halifax, Nova Scotia. He is a former tenured professor at St. Francis Xavier University, the founder of Rivalus, and co-founder of Headstrong.
Why did Darren Burke leave StFX?
He left his tenured role to focus fully on Rivalus after a cash flow crisis nearly cost his family their home. Running the company on the side meant he felt he was doing both jobs halfway.
What is Rivalus?
Rivalus, now RivalNutrition, is the supplement brand Dr. Burke founded. It was the first supplement brand made for athletes in drug-tested sport. He built it from a bootstrapped startup to a successful exit.
