A study published in the Journal of Sports Science and Medicine in 2026 found that ChatGPT outperformed certified personal trainers when answering common exercise questions — giving better answers to 6 of 9 questions and rated 90.7 percent accurate by independent experts.
That result is real. And as someone who owns a coaching gym and has a financial interest in the answer to this question, I want to respond honestly rather than defensively.
What the Research Actually Shows
The 2026 D’hoe et al. study is legitimate. ChatGPT, given open-ended fitness questions, outperformed nine certified Level-4 trainers. 90.7 percent accuracy. The finding makes sense: AI has processed an enormous volume of peer-reviewed research and can synthesize it clearly and quickly.
But the study contained a second number that didn’t make the headlines: 41.2 percent comprehensiveness.
Accuracy and comprehensiveness are different things. Accuracy measures whether the answer is correct. Comprehensiveness measures whether it covers everything relevant. The gap between 90.7 and 41.2 is the entire story.
Think of it like asking a very knowledgeable friend about medication for a headache. They accurately tell you ibuprofen reduces inflammation. What they don’t know — because you didn’t mention it — is that you’re already on a blood thinner. Their answer was accurate. It wasn’t comprehensive. Because they don’t know your full picture.
AI gives you accurate general answers. It doesn’t know your full picture.
What AI Genuinely Does Well
To be fair — and fairness matters here — there are things AI does genuinely well.
Explaining concepts. How does progressive overload work? What’s the role of sleep in fat loss? What’s the difference between hypertrophy and strength training? ChatGPT answers these clearly and accurately. If you want to understand the science behind your training, it’s a remarkable resource.
Generating programming frameworks. Ask for a beginner strength programme, a running build, or a meal plan framework — and you’ll get something structurally sound. A 2024 study found that AI-generated running plans weren’t rated optimal by coaching experts, but improved significantly with more specific input. The more context you provide, the better the output.
Democratising access to information. A July 2026 JMIR paper noted that AI chatbots can broaden access to fitness knowledge, “especially for people in resource-limited settings.” That’s genuinely good. Not everyone can afford or access a coach.
ChatGPT Health, launched in July 2026, now connects to Apple Health, MyFitnessPal, and medical records. The tool is improving. The gap between AI and coaching is closing in some dimensions.
So why can’t it replace a coach? Five specific reasons.
The Five Things AI Cannot Do
One: See you. Form is invisible to a text-based AI. Whether your knees are caving on a squat, whether you’re hyperextending your lower back, whether your breathing is off — it cannot see any of it. For beginners especially, form errors are the primary source of injury. The AI can describe a perfect deadlift. It cannot tell you whether yours is one.
Two: Know what it doesn’t know about you. The comprehensiveness gap. AI gives accurate general answers — but it doesn’t know you have a history of lower back pain that changes the entire programme. It doesn’t know you’ve been under extreme stress and your recovery is compromised. You’d have to tell it all of this — and then it still can’t observe you to confirm.
Three: Provide accountability. Research consistently shows accountability is one of the most significant predictors of exercise adherence. Knowing a specific person is expecting you on Tuesday changes whether you show up on Tuesday. AI can send reminders. It cannot notice you’ve been quieter than usual, ask how you’re doing, and give you a real reason to keep going.
Four: Adapt to your life in real time. You tell it your goal, it gives you a programme. Then your schedule changes, you get sick, you sprain your ankle. A coach sees all of this and adjusts immediately. The AI waits for you to start a new conversation and explain everything again from scratch.
Five: Flag its own errors for beginners. The 90.7 percent accuracy figure means 9.3 percent of answers may be wrong — and AI presents all answers with equal confidence. For someone with training experience who can identify when something sounds off, that’s manageable. For a beginner who doesn’t yet have the reference points to evaluate advice, a confident but wrong recommendation causes real harm.
How to Actually Use AI Well
Use it to understand, not to programme. AI is excellent at explaining the science behind what you’re doing. Use it the way you’d use a very well-read friend — for context, concepts, and the “why.” Let your coach handle the “what specifically you should do and when.”
Give it your full context. Research shows AI-generated programmes improve dramatically with more specific input. Age, training history, injuries, schedule, equipment, goal. The more you tell it, the more useful it is.
Treat it as a supplement, not a replacement. The July 2026 JMIR paper described the ideal as a hybrid approach: AI tools combined with periodic expert oversight. That’s right. AI broadens access to fitness knowledge. A coach applies that knowledge to you, specifically.
The Bottom Line
ChatGPT is 90.7 percent accurate at answering fitness questions. That’s real. But it’s only 41.2 percent comprehensive — it doesn’t know your injuries, your history, your life, or your form. It can’t see you, hold you accountable, or adapt to your real circumstances.
Use it to understand the science. Don’t use it as your coach.
Ready to experience the difference? Book your free No-Sweat Intro at Catalyst.
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Coach Chris Cooper is the owner of Catalyst Fitness in Sault Ste. Marie, Ontario. The Catalyst podcast releases new episodes weekly at catalystgym.com/blog.