It was never my dream to write a self-help book about health and wellness. I’m a tech entrepreneur and nerd with OCD, who grew up programming for fun. But over time, the decisions I made about what I put in my body and how I moved it started to have massively negative consequences.

Like a lot of entrepreneurs, I spent my younger days working more than one hundred hours a week, until I realized the toll it was taking on my mind, body, and life. When my body started to shut down, that’s when I started to view decision-making differently – and that’s when my new book, Unstoppable, was born.

Check out the following excerpt from the book about how I A/B tested my health, changed how I made decisions, and experimented on my body the way I experimented in business.


New Mindset

In the early days at Grasshopper, we were introduced to one of the leaders in a new area of digital marketing optimization. We brought him in to show us how to apply rapid A/B testing best practices to our marketing efforts, and it turned out to be an incredibly useful experience for us. Eventually, we ended up hiring him as a consultant to guide our growth marketing initiatives for a period of time.

Through our marketing consultant’s leadership, we built a culture of learning that changed Grasshopper forever. We eventually tested everything within the business and optimized for learning quickly. Multiple times, he proved to us through his experiments that what we’d assumed to be true in terms of effective marketing wasn’t backed up by the data. Whereas before we were brainstorming different marketing ideas and sinking money into them without giving them a second thought, our consultant pushed to require that our ideas were tested on a small scale before making a conclusion about their efficacy. This allowed us to focus on what was working versus making big bets—and wasting resources—on ideas that hadn’t been tested. After implementing this methodical approach, the company began to grow in ways I hadn’t seen before.

This iterative approach resonated with me deeply. Instead of relying on conventional wisdom to drive key outcomes, we relied on regular testing and actual data to make decisions. Years later, I wondered: What would it look like if I applied this A/B testing framework to my own health and wellness journey? What would it look like to objectively optimize my life, body, and mind with small tests, the way we were optimizing Grasshopper?

After all I’d learned about what was behind influential nutrition and diet recommendations from both prestigious medical journals and the USDA, I decided to inject a healthy dose of skepticism into my personal health and wellness research. Given my experiences with rigorous A/B testing at Grasshopper, I decided that the tests I’d run on myself would all be evaluated by the same framework, to avoid bias and make conclusions based on data. This provided the structure I needed to rule things out or in, and go deeper into areas that provided promising returns. At last, I was saying goodbye to what appealed to biased “conventional wisdom” and embracing an approach that would optimize my life, my body, and my mind.


My experiences as a young entrepreneur in college—and then as a founder and leader of a company in my middle to late twenties—had forced me to be bold, confront fears, and learn from my mistakes. Yet, when it came to my health, I’d taken the opposite approach, relying instead on conventional wisdom to guide my decision-making. Once I realized this, I restarted my health journey with two goals: more experimentation and more data collection.

The first area where I totally flipped the script was exercise.

After moving to Las Vegas, I joined a gym close to my office. Upon noticing that they had a yoga studio, I decided to try a class for the hell of it. To this day, I’m still not sure why I went for it—after all, I’d tried restorative yoga a few years before and didn’t enjoy it. Back then, I was also one of those guys who claimed to prefer so-called “masculine” workouts—things like weight lifting, marathons, triathlons, and the like. Truth be told, I saw yoga as a bit of a joke. But I’d also never taken a single class. So, in the spirit of experimentation, I changed that.

The first yoga class I went to was Vinyasa style, taught by a woman named Willow. And here’s what happened: it absolutely kicked my ass. Within minutes, I was sweating profusely, using muscles I’d never used before, and—best of all—I could tell that I wasn’t further damaging my knees.

Encouraged by this first class, I went to another taught by a man named John. This time it was heated.

This class kicked my ass even more. Instead of being all about competition, I discovered that yoga classes were about your own personal flow—your combination of breath, movement, and mindfulness. John would guide us through each pose, and once he felt like everyone understood how it worked, he let us move through the flow at our own pace. Unlike when I was on the elliptical or in spin class, yoga put my mind at ease. Instead of thinking about what I had to check off my to-do list, or the emails waiting for me at the office, yoga forced me to be fully present. It had a way of quieting my mind that was unlike any other physical activity I’d tried before. It was like remembering a dance, and with each step, I focused more on my breath and the movement that would come next. And nothing else.

Long story short: I got hooked on yoga. And, like everything else, I went all in. I started practicing seven days a week and making morning yoga a part of my daily routine. I started planning business trips around my yoga schedule, catching an afternoon or evening flight so I wouldn’t miss yoga in the morning, and so on. I even completed a 200-hour yoga teacher training. I just wanted to learn everything I possibly could about this incredible practice.

Yoga challenged me physically, but it was also a gateway to something even more important: mindfulness. I felt more at peace. And I even started to notice subtle shifts within myself throughout the day that went beyond the physical. I was less irritable. I was more present with friends and family. I had less judgment for myself and others, and was more compassionate.

Starting a yoga practice was a huge experiment. But it had a way of optimizing my health in much the same way I optimized those marketing experiments at Grasshopper back in the day. I started applying the framework to other areas of my life, asking myself simple A/B questions about how I felt after practicing yoga. Did I feel better or worse? Could I think more clearly throughout the day? Did my knees feel better or worse? Did I judge myself less when I looked in the mirror? On a scale of one to three, how did I feel compared to days when I was unable to practice? I logged it all as part of the process of data collection and analyzed the results.

The data was clear: something was changing. And even though I wasn’t sure where my journey was taking me, I knew that yoga was something I needed. I continued to experiment with it so I could get more data. During yoga teacher training, I lost some weight and got down to 190 pounds, but I gained a bit back once it was over. But it didn’t matter as much, somehow: yoga made me feel better than I’d ever felt in my life.


This post was written by David Hauser, founder of Chargify and author of the new book Unstoppable: 4 Steps to Transform Your Life.