I Replaced My Fitness Instructor With AI; Am Now Stronger and Happier

I used to feel like I needed to spend money to stay in shape — not just on the gym but also on classes, personal training, and enough Lululemon to dress a small Olympic team.

I was immersed in a landscape of gymfluencers and self-improvement culture, and that combined with my own poor impulse control, plunged me into a costly cycle where I felt like my ability to stay healthy was increasingly associated with spending.

However, I wasn’t getting any fitter despite spending over $100 each month on a gym membership, personal training, and workout gear. What finally worked wasn’t some militant app that blasted my phone with reminders or a new Apple Watch. It was self-discipline and an AI sidekick.

It’s been over two months since I replaced my personal trainer with AI, and I’ve become stronger, leaner, and saved hundreds of dollars, as a result.

To be clear, trading people for algorithms wasn’t my intention when I started out. After all, it was a person who got me hooked on fitness in the first place.

However, I have to admit that using AI to refocus has given me back ownership of my time, money, and motivation.

My fitness journey was erratic but not untypical

In my early 20s, I traveled frequently between cities, which made it hard for me to establish any consistent habits, including fitness. This lack of structure and haphazard routine came to a head when I moved to Cambridge for a master’s program.

Juggling full-time work with studies took its toll, and I found that the only real solution to a clean bill of mental health was exercise.

I lucked out that one of the instructors running classes at my local gym was brilliant and had a knack for pushing me just beyond my natural limits. I trained with him for about a year, but when he moved on, my motivation tanked.

I stayed on at the gym, but wasn’t getting what I needed from other instructors and the membership bills kept coming. Testing alternative spaces with Classpass and various free trials at other gyms was fine for a while, but without consistent guidance and encouragement, I started showing up less, making excuses, and procrastinating.

All the habit stacking and calendar updates in the world can’t help if you just don’t want to be somewhere.

Bribing myself with new gym wear and post-workout treats helped me show up, but that wasn’t sustainable either. The pounds were rolling away, but they were the wrong kind: sterling.

I decided to make a change.

I needed a mindset shift

I already used ChatGPT and Perplexity in other areas of my life — mostly for recipes, travel planning, and other kinds of research and troubleshooting. So, tailoring a personal exercise routine wasn’t difficult to start.

I used ChatGPT as a master app, entering my goals and progress each week and requesting new or updated workout routines.

I also used it to explore issues around willpower and discipline. Where once I might have taken a few days to read and sift out strategies and motivation from books, now I could find solutions in real time and dig into the reasons I might be holding myself back.

I even used ChatGPT to find recommendations for other free AI-powered apps.

The best of these was Cronometer, a nutrition and calorie-counting app, which I began using daily. I use the free version and it helps me track water intake, macros (carbs, proteins, and fats), fiber, iron, and vitamin levels.

I got curious about the results I was seeing with Cronometer and turned to ChatGPT again to learn more about nutrition.

I asked it questions like: Why does protein matter so much for muscle growth and recovery? How much do I need? What’s the best way to get it? Soon it was providing me with simple meal plans to boost my protein intake and better complement my workouts.

I also use a free app that ChatGPT recommended, Hevy, which tracks sets of reps in real time. I also use the free version of Gymmade, which offers a catalog of resistance training exercises with step-by-step instruction and animated illustrations; it’s been the perfect tool for confidently handling any free weights.

I’m finally seeing results

I’m now seeing real results across strength, stamina, body composition, and mood. My muscle definition improved, and I doubled the weight I was lifting in a matter of weeks.

Plus, the urge for expensive personal training has vanished. I dropped my gym membership and now I hit my local free outdoor gym instead.

I wouldn’t have made it to this point without the encouragement of that first brilliant instructor. However, what made the most difference was learning to hold myself accountable and build my own motivation and momentum without anyone’s help.

I didn’t set out to build a DIY fitness routine, but I’ve stuck to it longer than anything else I’ve tried on my own.