Why We Built Dorsi

Five years ago, I did not enjoy exercise, and I especially disliked strength training. It took several unexpected results in a health checkup for me to think seriously about my health. I decided to start with running.

At first, I could barely keep going for one kilometer. Over the next year and a half, I stopped and restarted many times. Eventually, I finished my first half-marathon in one hour and thirty-five minutes. Running became a habit, and those earlier test results later returned to their reference ranges.

But running did not resolve the neck and shoulder discomfort I had lived with for years. I began learning about back training and, for the first time, took strength training seriously. I had assumed building muscle was mainly about appearance. I came to understand that muscle also plays a role in how we stand, move, and handle daily life.

My strength training began with my back. When we later named the product, we thought of the Latin dorsum / dorsi, which relates to the back. The name Dorsi anchors us to where that journey began.

I also shared what I was learning with colleagues who had similar concerns. Many were willing to try, but after one or two sessions, they stopped.

They wanted to feel better. The real problem was that strength training required too many decisions.

Which exercises? How many days a week? How many sets? What weight? If you only have twenty minutes today, the equipment changes, or you miss a session, what should happen next?

I gradually realized that many people do not need more tutorials. They need a plan that tells them what to do now and continues to fit when life changes.

The name Dorsi also brings to mind the English word dose. That does not mean less training is always better, and it is not a shortcut. Everyone has limited time, energy, and practical options. Training calls for a realistic, sustainable dose shaped by a person’s goals and current circumstances.

An hour-long session and a ten-minute workout will not produce identical results. But whatever time someone can give today, a good plan should use it where it can best support the goal—not pretend that reality never changed.

That is what we want Dorsi to do: build an executable strength plan around a person’s goal, schedule, available equipment, and training history. When those conditions change, Dorsi reorganizes today’s session and upcoming training instead of offering an isolated one-off workout.

AI is not a substitute for exercise science, and it cannot make limited effort produce impossible results. We want to use it to understand the conditions people describe in everyday language, then turn established training principles and real context into a plan that is easier to follow. People should also be able to see why a plan changed and remain in control of the final decision.

My background is in technology and business. My co-founder has spent years working in big data and AI, and our team brings expertise in sport and health science. We train regularly, but we do not think every user should have to learn to think like a coach before they can begin.

We have also come to see strength training as more than the sets completed in a single session. It is part of long-term health. With permission, Dorsi can use selected Apple Health information as context and provide a Biological Age estimate to help people observe how some health signals change over time. It is a trend reference, not a medical diagnosis or a promise to reverse aging.

Today, Dorsi focuses on strength training on iPhone. Apple Watch can provide additional context, but it is not required to use the plan. We are starting with one concrete job: help people know what to do today and understand what their effort is building over time.

Life will not reserve a perfect block of time for training every day, and no one is always at their best. You do not have to wait until everything is ready, or treat today’s effort as meaningless because it was not perfect.