About · built by athletes
Built by someone who actually trains. And actually hurts.
Hi, I’m Sven. 39, dad of two, married to Nora, and somewhere in the last few years I turned a midlife crisis into a training plan.
By day I work in tech. On evenings, early mornings, and the occasional stolen lunch break, I’m a cyclist and a runner slowly talking himself into swimming, because apparently turning 40 legally requires attempting a triathlon.
I didn’t come to this as a natural. I rode Vätternrundan, 315 km, once cracking the prestigious “sub-9.” Then a snowboard crash broke my wrist and, somehow, broke my hatred of running. Six months after “I hate running,” I finished the 100 km Embrace Triple Trail Ultra in Kent, 17th male across the line. Six months and two more surgeries later, I finished my first 100-miler at the Fuji 100: 171 km, 7,300 m of climbing, 34 hours moving, top 10% of my wave. So when a plan asks you to do something hard, know that I’ve probably been there too, swearing, at 3am, on a mountain.
By the numbers (the honest version)
55–60
VO₂max
Blummenfelt runs a 95. I’ve made peace with it.
280–300W
FTP
42:00
10k PB
My own word for it is “meager.”
Imminent
Olympic readiness
Obviously.
Why this site exists
I obsess over the science. I read the papers, I track the numbers, I love a good formula. But most zone calculators are either a wall of jargon or a black box, and most athletes just want to know their easy, their hard, and how not to blow up. So I built the tool I wanted: every model in one place, the math shown plainly, no login, no wall, free. Pick your sport, punch in your numbers, get zones you can actually train by.
What I believe
- You don’t need pro numbers to be a real endurance athlete. You need consistency and a little patience.
- It does not have to be complicated. The fundamentals are simple; the discipline is the hard part.
- Move, move, move. The best longevity protocol is going outside and using your body. No supplement stack required.
- It should be fun. If you have a job, a partner, and kids who need you, training has to fit your life, not replace it.
Now go find your zones. And if you ever want a coach who reasons the way I do, that’s what Coach Kalle is for.
Not medical advice
TrainingZones is an educational training resource, not a medical service. The zones and formulas here are estimates for healthy adults and do not account for medications, cardiac conditions or other individual health factors. Consult a physician before starting or changing a training program, especially if you have a known health condition or any symptoms during exercise.