Thousands of Transformations.Worldwide.
Nearly three decades of consistent, honest, evidence-informed coaching.
From personal training in 1996 to pioneering flexible dieting and metabolic restoration online — Jennifer Kersten Fitness has been at the forefront of science-driven women's transformation for nearly three decades. This is the story of how it was built, what it stands for, and where it is going.
The Foundation Was Built
Long Before the Name.
Jennifer Kersten Fitness began in early 2013 under its original name, INJAFit — Inner Jewell Athletics. But the foundation began long before that.
Jennifer started personal training and leading group fitness in 1996 while completing high school. A former competitive gymnast and high-level athlete, coaching became a natural extension of her discipline and self-expression. What began as training sessions and group classes evolved into a focused interest in strength development, physique transformation, and nutrition science.
By 2001, she was actively competing in fitness and figure while coaching competitors and lifestyle clients. Over the next decade, she built experience across both performance-based physique coaching and general population transformation — witnessing firsthand the long-term effects of extreme dieting and metabolic stress.
From 2000 to 2014, Jennifer worked for Thrifty Foods — one of Canada's 50 Best Managed Companies — as Vitamins and More Manager. Working directly with the public on supplementation, holistic nutrition, and root-cause wellness strategies gave her a systems-based understanding of health that extended far beyond aesthetics.
Following the birth of her daughter — diagnosed with the rare disease mastocytosis — Jennifer reassessed her career path. Thrifty Foods supported her transition, allowing her to return for a year after maternity leave while she built her online coaching business. That period provided the bridge between corporate leadership and entrepreneurship.
One Mission.
Two Names.
In 2013, online fitness coaching was still emerging. Jennifer recognized a gap in the industry — particularly for women struggling with metabolic adaptation, chronic under-eating, and the psychological aftermath of extreme competition culture. Having personally navigated metabolic adaptation, weight regain, and years of disordered eating patterns tied to physique sport, she built INJAFit to challenge the prevailing model.
Inner Jewell Athletics. Founded at a time when rigid meal plans and clean eating dominated the space. INJAFit became part of the early movement advancing science-based protocols, macro education, and metabolic restoration for women.
The name changed. The mission did not. Structured, physiology-informed coaching that restores metabolism, builds strength, and eliminates extremes — delivered with the same standards that defined the work from day one.
Built to Challenge
the Prevailing Model.
At a time when restriction was the industry standard, the mission was clear and deliberately counter-cultural:
- End chronic under-eating — and the cycle of damage it creates
- Teach women how to fuel properly — with precision, not punishment
- Bring flexible dieting to the mainstream — before it was widely understood
- Normalize reverse dieting and metabolic repair — as standard protocol, not a last resort
- Build food autonomy instead of food control — so clients leave more capable, not more dependent
The company grew rapidly and aligned with leaders in evidence-based physique coaching, including Dr. Layne Norton and Sohee Lee. Jennifer became part of the broader shift toward data-driven methods within transformation coaching — at a time when that approach was still far from the industry norm.
Beyond the Screen.
Into the Room.
Beyond online services, the company hosted in-person retreats that drew women from across North America and internationally. These events combined training, education, and community — reinforcing autonomy, strength, and sustainable practices in an environment built entirely around women showing up for themselves.
Women arrived as clients. They left as advocates for their own health — with tools, knowledge, and a community that extended well beyond any single program. That ripple effect has always been part of the intention.
The Standards That Have
Never Changed.
From personal training in the 1990s to pioneering flexible dieting online, one set of standards has remained consistent throughout every iteration of this company.
Long-term over short-term.
Every decision is made with sustainability as the filter. Quick results that do not last are not results — they are a setup for the next cycle of restriction.
Physiology first.
Coaching is informed by science, not trends. The body responds to specific inputs — and understanding those inputs is what separates transformation from temporary change.
Autonomy over dependence.
The goal is always to make the client less dependent on the coach over time — not more. Education is built into every program, every check-in, every interaction.
Honest coaching over comfortable coaching.
The women I work with deserve the truth — about what works, what does not, and what the data actually says. Honesty delivered with care has always been the standard.
Nearly Three Decades
of Consistent Work.
- 1996Coaching begins. Personal training and group fitness while completing high school. A former competitive gymnast finds her professional calling.
- 2000Joins Thrifty Foods as Vitamins and More Manager. Fourteen years working directly with the public on supplementation, holistic nutrition, and root-cause wellness.
- 2001Competing and coaching simultaneously. Fitness and figure competition begins alongside coaching competitors from amateur ranks to IFBB Pro level.
- 2013INJAFit launches. One of the early online coaching platforms advancing macro-based nutrition, metabolic restoration, and science-driven transformation for women.
- 2013–2018Retreats and community growth. In-person events draw women from across North America and internationally. Alignment with evidence-based coaching leaders including Dr. Layne Norton and Sohee Lee.
- 2019Rebrands to Jennifer Kersten Fitness. The name changes. The mission, standards, and commitment to long-term transformation do not.
- TodayTwo signature programs. Thousands of women transformed. The same commitment to precision, patience, and long-term strategy that has defined this work from the beginning.
The Standards Have Not Changed.
Neither Has the Commitment.
Nearly three decades of consistent, honest, evidence-informed coaching. If you are ready to stop cycling and start building — I am ready when you are.
Apply to Work With Me