Nearly Three Decades.One Unwavering Mission.
I did not stumble into this work. I was built for it.
Through sport, competition, personal crisis, and the kind of hard-won knowledge that only comes from living inside the problem you are trying to solve — this is the truth of how I became the coach I am, and why the women I work with trust me with something as personal as their bodies.
Built by Sport.
Driven by Discipline.
Movement was never something I chose — it was something I was. From a young age I was a competitive gymnast, training at a level that demanded precision, physical resilience, and a relationship with my body that most kids never develop. The sport gave me a foundation I have drawn on every single day since.
Gymnastics teaches you things that no textbook can. It teaches you that the body is capable of far more than it initially appears. It teaches you how to fall, how to recover, and how to push through discomfort with intention rather than desperation. It teaches you that discipline is not punishment — it is the price of becoming.
It also taught me the cost of extreme physical demand on a young body. The pressure to be small, light, and performing at all times planted seeds I would spend years unravelling. But that understanding — earned, not borrowed — became central to how I eventually learned to coach.
By 1996, while still in high school, I had already started personal training and group fitness coaching. It felt less like a career decision and more like an obvious extension of who I already was. I understood bodies. I understood effort. And I understood what it meant to want more from yourself than you currently had.
The Stage. The Damage.
The Real Education.
In 2000 I began competing in fitness and figure. What started as personal ambition became one of the most important and most costly educations of my life.
I was learning to build my own body while simultaneously learning how to build others. I coached competitors from the amateur ranks to the IFBB Pro League. I built women who earned professional status and stepped onto world-class stages.
But behind the results, my own body was telling a different story. The restriction cycles. The extreme competition cuts. The rebound weight that came back faster and heavier each time. I was living inside the very cycle I would eventually dedicate my career to dismantling.
The physique world normalises extremes. It celebrates restriction and calls it discipline. It rewards the stage result and ignores the aftermath. I experienced that aftermath firsthand — and it reshaped everything I thought I knew about what it actually means to transform a body.
I understand extreme dieting not from theory. From my own body, my own history, and the years it took to rebuild what I had damaged.
The Rebuild.
And What It Proved.
Repairing my metabolism was not a quick fix. It was years of deliberate, strategic work — learning to fuel properly, training with intention rather than punishment, and slowly rebuilding the trust between my body and myself that years of restriction had eroded.
By 2011 — when my daughter was born — my metabolism was repaired. My body was strong, responsive, and functioning the way a well-fuelled, well-trained body should. That was not luck. That was the result of over a decade of doing the work.
In the years that followed — through health challenges, a hysterectomy, and everything that life has thrown at me over the last seven years — my body has held. Not because I was lucky. Because the foundation I built was strong enough to withstand it.
That is what metabolic repair actually means. Not just a better before and after photo. A body that can handle your real life — the hard seasons, the health scares, the hormonal shifts, and the ordinary chaos of being a woman in the world. A body that does not fall apart when life gets hard.
That understanding is not in a textbook. It is in my history. And it is in every program I have built since.
Building Something
That Actually Lasts.
From 2000 to 2014, alongside my coaching work, I spent fourteen years with 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 gave me a systems-based understanding of health that extended far beyond aesthetics.
In 2013 — with my metabolism repaired, my daughter in my arms, and nearly two decades of hard-won knowledge behind me — I launched INJAFit — Inner Jewell Athletics. The mission was direct: end chronic under-eating, teach women how to fuel properly, and normalize reverse dieting and metabolic repair.
At a time when rigid meal plans and clean eating dominated the industry, INJAFit became part of the early movement advancing macro-based nutrition, science-driven strength training, and metabolic restoration. The company grew into retreats, communities, and thousands of transformations across North America and beyond.
In 2019, the business became Jennifer Kersten Fitness. The name changed. The standards did not.
What I Actually
Believe About This Work.
I do not coach for short-term change. I never have. Short-term change is easy to produce and nearly impossible to maintain — and I am not interested in adding to the pile of programs that leave women exactly where they started, six months later, blaming themselves.
I coach for stability. For autonomy. For a body that can handle the full weight of a real life — the stress, the travel, the celebrations, the hard seasons, and the ordinary Tuesdays that make up most of existence.
And I coach for resilience. Because the women aging alongside me — the ones who competed, who dieted hard, who are now navigating perimenopause and hormonal shifts and bodies that feel unfamiliar — they do not need another restriction program. They need a body that is strong enough to handle what is coming. I know that because I built mine to do exactly that.
Restriction is not a strategy.
It is a short-term tool that becomes a long-term problem. Every sustainable transformation I have ever built started with eating more — not less.
Your body is not your enemy.
It is responding to information. Change the information — the food, the training, the stress, the sleep — and the body follows. Every time.
Phase-based coaching works.
There is no one-size plan. There is a sequence — and skipping steps costs you everything.
Autonomy is the goal.
A great coach works to make herself less necessary over time — not more. Every client I work with leaves with the knowledge to manage their own body independently.
I Have Lived Every Part
of This From the Inside.
There are a lot of coaches in this space. Many of them are talented. What separates my work is not a certification — it is the combination of nearly three decades of hands-on coaching, personal experience with metabolic damage and repair, and the proof that the system works not just for my clients but for my own body through everything life has thrown at it.
I repaired my metabolism. I built a body strong enough to withstand health challenges that would have broken a body built on restriction. I am still here, still strong, still coaching — and the women I work with get to benefit from every hard lesson that journey taught me.
- 1996Began coaching while still in high school. Fitness training and group fitness from day one.
- 2000Began competing in fitness and figure while coaching competitors from amateur to IFBB Pro level. Also joined Thrifty Foods as Vitamins and More Manager.
- 2000–2010Lived and repaired metabolic damage through multiple rebound cycles from competing. Built the methodology that would become the foundation of all future coaching.
- 2011Metabolism fully repaired. Daughter born. The foundation that would carry her through everything that followed was already in place.
- 2013Launched INJAFit — one of the early online platforms advancing macro-based nutrition and metabolic restoration for women.
- 2013–2018Retreats and community growth. Women from across North America and internationally. Alignment with evidence-based leaders including Dr. Layne Norton and Sohee Lee.
- 2019Rebranded to Jennifer Kersten Fitness. The name changed. The mission did not.
- TodayTwo signature programs. Thousands of women transformed. A body built to last — and a coaching philosophy proven by the life that tested it.
Your Forever Home Body
Starts Here.
If this resonates — if you recognize yourself somewhere in this story — then you are exactly who I built this work for. I am ready when you are.
Apply to Work With Me