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. Evenings, early mornings and stolen lunch breaks, I’m a cyclist and a runner slowly talking himself into swimming, because turning 40 apparently requires a triathlon.
I am not a natural. I rode Vätternrundan, 315 km, and once cracked the prestigious “sub-9.” Then a snowboard crash broke my wrist and, somehow, my hatred of running. Six months later I finished the 100 km Embrace Triple Trail Ultra in Kent, 17th male. Two surgeries after that, my first 100-miler at the Fuji 100: 171 km, 7,300 m of climbing, 34 hours, top 10% of my wave. When a plan asks you to do something hard, I’ve been there, 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 and love a good formula. But most zone calculators are a wall of jargon or a black box, and most athletes just want 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, free.
What I believe
- You don’t need pro numbers to be an 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. With 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 want a coach who reasons the way I do, that’s Coach Kalle.
Not medical advice
TrainingZones is an educational resource, not a medical service. The zones are estimates for healthy adults and ignore medications, cardiac conditions and other health factors. Consult a physician before starting or changing a training program.