A few months back, I found myself with a somewhat last-minute marathon entry, and a realization that there weren’t too many 12-week marathon training plans out there. Sure, I could have (and probably should have) used a coach to create a plan that would work for my timeline and goals. Instead, I spent hours toggling between five different programs, creating a hodge-podge of a plan that ended up working okay.

If I found myself in the same situation today, I could have asked ChatGPT, the AI chatbot that launched in late November, to make a plan for me. Curious, I recently decided to play around and see what I would have gotten. Depending on how much information I gave it and how I phrased my query, it sometimes gave me a reasonable program, helpfully building mileage week-to-week. Another time I asked, it gave me a plan with zero speedwork, an essential part of nearly any race training plan. Another time, it puzzlingly suggested I do back-to-back long runs every weekend.

In theory, ChatGPT can create not only race training plans but workouts of any kind—from a 30-minute strength session to a three-month full-body fitness program. It didn’t take long for curious exercisers to start testing the chatbot’s potential as a personal trainer: Though it seems most have a healthy skepticism about what it returns, MIT Technology Review reports that one man in London, who has no fitness credentials, is now selling workout plans generated by ChatGPT for $15 a pop.

While it’s possible that implementing whatever fitness advice ChatGPT spits out could make for a passable workout, it’s a risk. You might end up doing workouts not suited for your body, or get results that wouldn’t make sense in any circumstance, like running 19 miles the day before a marathon, as it suggested to this writer.

The limits of ChatGPT for fitness

Ted Vickey, PhD, founder of health technology company FitWell and faculty member in the kinesiology department at Point Loma Nazarene University, points out that though ChatGPT’s popularity has exploded in the three months since it launched, it is still only a beta product intended solely for research purposes. There’s still much we don’t know about it, and it’s far too soon for any academic research on ChatGPT’s potential for the fitness industry.

Also important to know: ChatGPT’s information is slightly out-of-date, since it’s not yet connected to the internet, and is only updated intermittently. Though the science around fitness and exercise doesn’t change all that rapidly, keep in mind that the technology won’t know about anything that’s happened in the past year or so (you probably wouldn’t want to ask it for tips on 12-3-30 workouts, for instance).

We also don’t know where exactly the chatbot is getting its information at any given moment. ChatGPT works almost like an interactive search tool, says Shayan Azizbaeigi, SVP of product, fitness, and wellbeing at Xplor Technologies. Anyone who has gone down a Google fitness rabbithole knows that there’s lots of inaccurate workout advice online. The difference with using ChatGPT is that you don’t know the source, so it’s impossible to figure out whether what you’re getting is legit without cross-checking the information elsewhere.

Of course, these limitations apply when asking ChatGPT about nearly anything. But using it to generate workouts comes with particular risks. For one, producing a workout that will work for your particular body requires being highly specific in your request to the chatbot—like including your fitness level, any injuries, and any goals you’re working towards. But also, says Azizbaeigi, right now this early version of ChatGPT doesn’t always handle so much information well, and may fail to take into consideration everything you’re telling it.

Plus, says Paul Romeo, a trainer and owner of two technology-driven Koko FitClub studios in Massachusetts, most everyday exercisers likely wouldn’t know the right questions to ask ChatGPT, or even be aware of things that would be helpful for ChatGPT to know, like a weak muscle group that a fitness professional could help identify. “If you don’t know exactly what to ask ChatGPT, you could end up with a program that would exacerbate an injury instead of helping you work around it,” says Romeo.

Even if you give the chatbot all the right information, what it spits out may still just not make sense. The exact same inquiry can yield completely different results, and I found that it often contradicted itself, or gave oversimplified answers to questions where there is disagreement amongst professionals, like whether you should foam roll your IT band, or if it’s bad to always run in carbon-plated shoes. Plus, says Azizbaeigi, ChatGPT can be very confidently wrong. “If it’s something you’re not an expert in, some of the stuff that it spits back, you’re like, this has to be right,” he says. Diligent fact-checking with a healthy dose of skepticism is key.

When ChatGPT could be helpful

If you want to try to use the technology to generate a workout, be as specific as you can: Mention any injuries you’re working with, or whether you’re a beginner at something. Know that the tool is meant to be used conversationally, so if the chatbot provides something that doesn’t seem right, you can ask more questions or provide feedback to refine what it’s offering you. (Not only will this likely improve the results you’re getting, but it will help the AI learn and give better answers in the future.)

Run any workouts by an expert before trying them, suggests Romeo, or see if they align with what you find in reputable sources. “I think you need that interaction with an actual human to really make it work for most people,” he says. “That’s why people come to us—there’s a lot to know about how to design a workout: How much weight do you use? What order do you do the exercises in? And most people don’t have time to learn all that.”

Romeo says that ChatGPT could be more helpful for a fitness professional, who could better evaluate and tweak the results. Azizbaeigi agrees, and says that the primary purpose he sees ChatGPT serving right now is brainstorming and ideation in personalized fitness. Maybe a trainer wants some new ideas for exercises to do on glute day, for instance.

The good news: ChatGPT will only get more accurate over time, says Vickey, especially as Google launches its competitor, Bard. But for now, it’s probably best to stick to workouts that have been crafted (or at least refined) by human hands.