Man Turned ChatGPT Into a Fitness AI That Helped Him Lose 26 Pounds

• A desk worker who hated running asked ChatGPT to write a workout plan to get him addicted to exercise. 
• Now he runs six days a week and loves it. Along the way, he lost weight and improved his health. 
• ChatGPT has the potential to provide accessible coaching — but be wary of errors and other limitations. 

A Seattle-based technologist said he got hooked on a running routine, improved his health, and lost 26 pounds — not with the latest fitness influencer program or big-box gym membership, but thanks to a bot that’s freely available online. 

Greg Mushen told Insider that he turned to AI for help developing a healthier routine in February, in part to keep up with his 6-year-old daughter. “She’s at that magical age when she’s developing a personality of her own, and I want to be around to see different milestones,” he said. “I needed to change my lifestyle.”

Three months later, Mushen said he’s lost weight and seen major improvements to his energy as well as measures of heart health like his resting heart rate. 

“It’s been fun to see those metrics change, I just feel so much better,” he said.

While Mushen is tech-savvy, he said using ChatGPT as a coach is something anyone could do, pointing out it could have major benefits for boosting motivation as well as saving time and money. But it also requires some fact-checking and careful prompting, so it’s not likely to put personal trainers out of work just yet.  

ChatGPT made running fun by breaking it down into really easy wins

Mushen, who lives near a running trail, said he has hated running every time he’s tried to get into it. 

As a tech worker who spends a lot of time coding, Mushen was very familiar with ChatGPT, an artificial intelligence (AI) chatbot. ChatGPT can draw from massive data sets and uses computing techniques to provide an encyclopedic knowledge through conversational responses. As a free, versatile resource, finding creative ways to use the chatbot in everyday life is a growing trend, with people asking it to handle everything from their work emails to their dating app conversations.  

Mushen had the “whimsical” idea to prompt the bot to act as if it had doctorates in sports psychology and neuroscience, asking it to devise a plan to get him addicted to running. 

“I was curious about what would happen, but didn’t think it would work,” he said.

After some experimentation and several rounds of prompts, ChatGPT produced a plan that seemed viable and low risk. The only problem, Mushen said, was that it seemed too simple to work.  

For instance, the plan didn’t recommend any actual running until day three — and then only suggested five minutes of pounding the pavement. 

“It seemed really strange that the steps were so small. I’m a ‘go to 11’ person, really all in, and so this was the opposite of how I probably intuitively would have done it,” Mushen said. 

Still, it seemed like a low-stakes experiment, so he followed the first step right away, getting up and putting his running shoes by the door. To his surprise, he immediately felt more invested in the project. 

“Even doing that small task, I was bought in,” he said.  “It was just so easy that when I was done I remember feeling accomplished.”

The slow pace kept burnout at bay 

Mushen stuck to the plan, which continued to be easier than he expected, with plenty of rest days and runs that stopped well short of exhaustion. Counter-intuitively, the incremental pace of the program actually got him fired up to keep going, according to Mushen. 

“It had an interesting effect on me because it was holding back so much, for whatever reason that made me want to do it more,” he said. 

Previously, Mushen said he tended toward grueling exercise sessions that left him achy, depleted, and not eager to repeat the process.

In contrast, the program provided by ChatGPT built up the workload gradually. Now, Mushen said he does six running workouts a week, including four easy runs of about 45 minutes to an hour at a pace of around 13 minutes per mile for overall health and aerobic capacity. He’s recently added sessions at higher intensity, such as hill sprints, but in shorter sessions of about half an hour. 

“It’s something I really look forward to now,” he said. “I had a tendency to go really hard, get burned out. The maxim burned into our collective consciousness is no pain, no gain. But I’ve learned that it’s not always right.”

AI can help you save time and money on workouts, but it may not replace a personal trainer

Mushen said that his experiment with ChatGPT didn’t necessarily provide anything he couldn’t get from a coach or some online research, but it provided an accessible, free way to approach his goals. 

“It saved me so much time. I probably wouldn’t have done it if I had to go read books on running,” he said. “A coach would have been the way to go, but didn’t know if I wanted to invest in that up front, so ChatGPT was a good compromise because it’s free.” 

However, experts have warned that bots can sometimes come up with false or out-of-context information, so it’s important to fact check any advice offered by AI. Mushen navigated this by asking ChatGPT to cite research he could then reference to see if it was legit, and also made sure the advice it gave seemed safe and reasonable before trying it. 

The advantage of AI is that it can help generate ideas and organize information in ways you might never think to ask on your own, at least at first, according to Mushen. 

And using the ChatGPT workouts has helped him progress to the point where he could benefit even more from hiring a trainer to provide personalized goals and additional expertise. 

“I’m still a beginner but I’m in such a better position to even evaluate what a good coach is. Before, I never would have thought of getting a running coach. Just the thought would be so bizarre,” he said.