Hi, I’m Karl Etzel. I’ve had the good fortune to spend most of my career working at the intersection of healthcare, fitness, and technology. I’m also the lucky dad of two great sons.

We’ve been working out and staying fit together since they were little. They’re not so little anymore (they’re both bigger than me at this point), but we still enjoy a run or ski trip together when they can fit me into their calendars. I built TeenTrainer to help all the parents who are not fitness nuts, health professionals, or plugged into the world of fitness research. I hope you find it useful!