About Sandy

It started with my wife

My wife Sandra has struggled with getting into a gym routine for years. Finding the clothes, driving there, changing again — there were just enough small hurdles that it was always too easy to skip “just this once.” And “just this once” had a way of stretching into months.

She tried different gyms and classes, but nothing stuck. So we set up a simple home gym in the garage, figuring that removing the commute might be the thing that finally made the difference. And it was — she actually started showing up. But a new problem appeared: after years away from the gym, she didn't know what exercises to do, in what order, or how to plan around what she'd done the day before. At a gym there are a million machines to guide you. At home she had some dumbbells and resistance bands.

I'm a pretty regular gym goer, so I started planning her workouts. But even I found it tricky with limited equipment, and I couldn't keep doing it forever. There had to be a better way.

A huge solution for a small problem

I'm a software engineer, and software engineers excel at two things: optimising workflows and building wildly over-engineered solutions for simple problems. This felt like the perfect chance to do both.

I built a small web app for Sandra and called it “Train Sandy.” It needed to feel friendly — cute, even, like my wife — so I gave it an avatar. She has dark hair. The avatar has dark hair. Close enough.

Then it got good

Sandra had plenty of opinions on how to improve things, and being the loyal husband that I am, I spent many a night fulfilling feature requests, squashing bugs, and smoothing out rough edges.

Before long the app had become surprisingly capable. The AI was generating workouts that fit what she actually liked, carefully balancing muscle groups across days, and adapting to what she'd done recently — or hadn't. What Sandra loved most was that she didn't have to think at all. She'd log in, press a button, and get a workout that just made sense.

I'm much more opinionated about how I train, so I wasn't sure it would work for me. But watching her enjoy it, I figured I'd give it a shot. I added the ability to describe what you want in a workout, and immediately fell in love with that flow. I soon started using Sandy every day.

As often happens when you actually use the thing you're building, it just kept getting better:

• I wanted a streak counter for motivation — added it.
• I couldn't find the resistance bands one morning and needed to tell Sandy to swap them out of today's workout — so I added the ability to tweak a workout after it's generated.
• We bought a treadmill — added equipment management.
• And so on.

From our garage to your screen

Sandra and I are very different when it comes to exercise, but we'd found something that worked for both of us. When we started seeing real, tangible results, the thought was obvious: if it works for us, it probably works for others too.

So I polished it up, put it on the big scary internet, and here you are. Who knows — it might just work for you too ❤

— Sverrir Sigurðsson