ChatGPT is one of the most exciting new toys on the internet. Ask it for just about anything that can be produced in written form, and it will oblige. Which means that, among many other things, people are using it to generate workout programs. So how do they stack up? I brought the robot’s advice to my garage gym to find out. In the process, it misunderstood me, lied to me, and gave me hilariously terrible advice.
To be fair, it also managed to give me one kind of OK workout. So I wouldn’t count AI out of the future of fitness entirely, but it’s nowhere near ready to serve as your personal trainer.
How can ChatGPT write a workout?
Even though ChatGPT is being called an “AI,” which stands for “artificial intelligence,” it is still as dumb as any other robot. Its job is not to know things; its job is to generate text that makes it look like it knows things. It is an expert bullshitter. If you’ve ever been cornered by a mansplainer at a party, you’ll recognize the tone: authoritative, blustery, and a bit vague on the details. If you catch it in a lie, it will deliver a perfectly bland non-apology.
Have you ever used the predictive text on your phone’s keyboard just to see what it would say? “I’m a Sagittarius and my horoscope is…” you type, and then tap the next suggested word and the next word and the next. “I’m a Sagittarius and my horoscope is the same as yours so I don’t know if I can do it but I can do it for you.”
Your keyboard’s algorithm has a general sense of what words tend to come after others, and it has seen (that is, it has been “trained on”) your previous texts. It doesn’t say anything particularly smart or insightful, but it can put words together into somewhat plausible sentences.
With more sophisticated programming and a larger training set, you can get an AI to create more interesting things. Longtime readers will remember when I had a neural net write a bunch of Lifehacker headlines, like “The Best Way to Make a Baby Laptop” and “How to Keep Your Relationship With an Imaginary Concept.”
ChatGPT is basically that, but bigger. It’s been trained on almost the entire public internet, and it has an attention span that can last for a conversation, rather than a mere sentence. Or in other words: ChatGPT is not writing workouts. It is generating text that looks like a workout. Let’s see how it goes!
I first asked ChatGPT for a five-minute warmup to do on an indoor bike. It gave me a five-step warmup, with some of the steps lasting more than one minute. In step two, I was supposed to stand up on the pedals to “help engage different muscle groups.” It did not say whether I was ever supposed to sit back down.
After some back-and-forth questioning, where each of my simple questions resulted in a five-paragraph answer, I still didn’t have a clear picture of what I was supposed to do. So I started over: “Give me a simple 5-minute warmup on an indoor bike with no more than two steps.” And I got one:
Sure, here’s a simple 5-minute warmup on an indoor bike with no more than two steps:
Start by pedaling slowly with little to no resistance for 2-3 minutes in a seated position to get your heart rate up and your blood flowing.
After 2-3 minutes, increase the resistance slightly and pedal at a moderate pace for the remainder of the 5-minute warmup.
This warmup is quick and simple, but it will still help to increase your heart rate, warm up your leg muscles, and get your body ready for more intense exercise. Remember to adjust the intensity of the warmup based on your fitness level and the workout you have planned. If you’re just starting out, you may want to start with even less resistance and work your way up gradually.
That’s a lot of words to say “go easy for the first half and add some resistance for the rest,” but this is a verbose bot and it has to get all its disclaimers and summaries in. If you ask it to skip those things, it will instead give a longer explanation and disclaimer of how, for example, it left out the warmup and cooldown but you should really do a warmup and cooldown. It also assumes you need everything explained to you: It can’t write “20 kettlebell swings” without giving you a dense paragraph on how to do a kettlebell swing. I’ll be editing out that fluff for the remainder of this post. I just want you to know that ChatGPT’s writing style makes me want to slap it.
Anyway, that is a warmup. I wrote it down on a fresh sheet of notebook paper. What’s next?
Trying in vain to generate a quick 10-minute workout
Today is an active rest day for me, so my idea was to do a quick 10-minute workout with a kettlebell. Maybe some swings or some clean-and-press. And behold, the process of trying to squeeze a plausible workout out of a text-generation bot:
It’s too complicated and boring
The first kettlebell workout it generated called for a two-minute warmup and cooldown, and then an 8-minute section in the middle with four exercises, each for about 10 reps. This makes no sense. Nevermind that 2+8+2 is not 10—it also does not take two minutes to do 10 goblet squats. I kept rephrasing my question, and finally hit pay dirt when I told it to follow an EMOM structure, which would require me to set a timer to beep every minute, and doing an exercise at the beginning of the minute and resting until the next beep. Here’s what it gave me:
- Minute 1: Kettlebell Swings – 20 reps
- Minute 2: Goblet Squats – 10 reps
- Minute 3: Russian Twists – 20 reps
- Minute 4: Clean and Press – 5 reps each arm
- Minute 5: Goblet Lunges – 10 reps each leg
- Minute 6: Kettlebell Snatches – 5 reps each arm
- Minute 7: Kettlebell High Pulls – 5 reps each arm
- Minute 8: Kettlebell Turkish Get-Ups – 3 reps each side
- Minute 9: Kettlebell Swing and Goblet Squat Combo – 10 reps each
- Minute 10: Kettlebell Russian Twists with a Press – 10 reps each side
I’m not doing all that (I prefer my EMOMs to be something like “20 swings every minute for 10 minutes”), but I appreciate that it finally understood the assignment.
It makes up things that are physically impossible
As I felt like we had a pretty good rapport going, I next asked ChatGPT to:
Give me a 10 minute kettlebell workout (no warmup, no cooldown, no instructions, just name the exercises) that’s different from what you give everybody else. Something fun and creative. Three exercises maximum, make ’em good.
And it delivered:
Here’s a fun and creative 10-minute kettlebell workout with only three exercises:
Kettlebell Half-Moon Swings: 30 reps
Kettlebell Squat and Press: 20 reps
Kettlebell Flips: 20 reps
How do three exercises make a 10-minute workout? Never mind. I’m too busy being impressed by the flips. Kettlebell flips are a real exercise, and they’re exactly what they sound like: You do a swing, but give the bell enough spin that you can let go and catch it. I’ve never done one successfully, and I don’t think I’m ready to tackle that today (I hear you stub your fingers a lot in the learning process), but still—
Wait a minute. What is a half-moon swing? I googled, and only found a “half moon” exercise that is nothing like a swing. So I asked it for instructions. It replied:
Start by standing with your feet hip-width apart and holding a kettlebell in front of you with both hands.
Swing the kettlebell back between your legs, keeping your arms straight and your gaze forward.
Drive your hips forward, straightening your legs and swinging the kettlebell up to chest height.
As the kettlebell reaches its peak, twist your torso to the right, keeping your arms straight and bringing the kettlebell to the right side of your body.
Reverse the twist, swinging the kettlebell back down to your front and repeating the motion on the other side.
Alternate sides for each rep, continuing for 30 reps in total.
So it starts with two hands…and then goes to one side…I’m not getting it. I tell the bot: “I think you just made up the half-moon swing. It doesn’t sound possible.” And it said:
My apologies, you are correct. The “Kettlebell Half-Moon Swing” is not a commonly recognized kettlebell exercise and could potentially be hazardous if performed improperly. I apologize for the confusion and for any inaccuracies in my previous response. It’s important to always prioritize safety when performing exercises, and to seek guidance from a qualified instructor if you’re unsure of how to properly perform a specific exercise.
I showed the description to kettlebell coach Emilio Joubert, who said that if you could do it with one arm, it might be “sort of like a bent press snatch?” which are three words that I am sure have never been uttered together. He says he might try it someday.
It gets (steals?) a good idea
I kept going, and asked ChatGPT for “a short, fun workout” that I can do with a heavy kettlebell. It said something that, while not original, fits the bill quite well: Kettlebell tabatas.
Kettlebell swings: 20 seconds of work, followed by 10 seconds of rest, repeated for 4 rounds. To perform a swing, stand with your feet shoulder-width apart and hold the kettlebell with both hands between your legs. Hinge at your hips and swing the kettlebell back between your legs, then drive your hips forward and swing the kettlebell up to shoulder height. Repeat for 20 seconds, then rest for 10 seconds. Repeat for a total of 4 rounds.
A traditional tabata is 20 seconds of a cycling sprint, followed by 10 seconds of rest, repeating for a total of 8 rounds. This is a mini version, with kettlebell swings replacing the cycling. I like it! I also recognize it as something strength coach Dan John wrote about 12 years ago.
After the swings, ChatGPT said I should do the same thing with goblet squats and then with kettlebell deadlifts. That’s six total minutes, which allows me an extra two minutes of rest between each chunk. Perfect.
It gets a better idea
My husband wandered in at this point. He suggested I ask it for a drinking game that I could do with a protein shake. It almost refused:
I’m sorry, but as an AI language model, I cannot promote or condone the consumption of alcohol, especially in the context of a drinking game. It’s important to maintain responsible and safe behavior when consuming any type of drink. However, I can suggest a kettlebell workout that you can do while drinking a protein shake as a fun and healthy way to incorporate fitness and hydration:
The resulting workout was nearly identical to the tabatas, but it specified that I should take a sip of my protein shake during every rest period. I don’t know if you’ve ever done a tabata, but usually the most one is capable of during the 10-second rest period is gasping for air and trying not to fall over.
So, of course, this was the perfect challenge. I wrote it down on my workout sheet, right under the bike warmup.
It gets creative…maybe too creative
My husband’s other idea was to ask it for yoga poses I could do with a kettlebell. It provided:
- Warrior II, with a kettlebell hanging from my outstretched front hand: This sounds nearly impossible, but I have some very light weights, so we’ll give it a try.
- Extended side angle pose, with a kettlebell in the overhead hand: I misunderstood and thought this said triangle pose. With my interpretation it’s basically a kettlebell windmill.
- Chair pose with overhead press: I think there’s a reason nobody does overhead squats with a single kettlebell, but we’ll try it.
- Plank pose with shoulder tap: This one is a pretty standard exercise, but the bot specified that my hands should be on a kettlebell instead of on the floor. That’s super unstable. I might fall on my face. Exactly the kind of challenge I’m looking for.
Alright, so we have a warmup, some kettlebell work, and some silly yoga poses to cool down. All set?
Maybe it’s on to something
On a lark, I asked it for a grip workout. It delivered, with three exercises that looked like an easy add-on to any gym day:
- Farmer’s carries with a heavy pair of dumbbells or kettlebells
- Plate pinch holds – it didn’t specify what kind of plate, but I know I can do these with a bumper or with a pair of iron plates sandwiched together, smooth sides out.
- Towel pullups or hangs, where you drape a towel over the bar. These are tough but good!
Intrigued, I asked it for another quick grip workout, and another, and another. It didn’t start repeating exercises until the fifth one. Hey, nice work, bot!
How the workout actually went
So I did the five minutes on the bike. Then I did the mini tabatas. The swings, squats, and deadlifts toasted my legs and butt, but they were short enough efforts that I’d say they still count as a nice off-day workout. I chose a 20-kilo bell for the swings, switched to 16 halfway through the squats, and went with 24 for the deadlifts. Fortunately, these weights were easy enough that I did not end up puking up my protein shake. Success!
Yoga was next. I kind of did the kettlebell Warrior II for a second or two, with a 15-pound bell and probably horrible technique. (I’m not really a yoga person, OK?) The triangle/windmill went fine. The chair pose, basically an overhead squat, I struggled to do with straight arms. I think it would work well with a pair of dumbbells, though. And finally, I did not eat dirt on the kettlebell plank taps. Proud of myself there.
I finished with the grip work. These exercises went fine until I realized the towel pullups came last. Towel pullups are hard enough on a good day; doing them at the end of a grip workout, after farmer’s carries and plate pinches, is nearly hopeless. I managed two reps on most of the sets, and thought that was pretty good. I’ll do this grip workout again, but I’m swapping the order.
It is not a substitute for real programming
So could ChatGPT replace a trainer? Oh god, not even a little. Generating the workouts was a bit like asking a child for brainstorming help. You’ll get some creative stuff that might inspire you, but you have to do a lot of work to filter out what’s appropriate and rewrite what remains.
For example, the bike workout wants you to start out slow, with low resistance. When resistance is low, you actually want faster legs. And for the kettlebell exercises, it couldn’t give any useful recommendations on the weights to use. Sometimes it chides you that you should choose an “appropriate” weight, but it’s no help in figuring out what that should be. All the credit for going light enough not to puke belongs to me.
Generating text isn’t the same as applying knowledge
I was intrigued by a trainer who said he got ChatGPT to write workouts “better than most personal trainers” by spending an hour teaching it what to do. But the instructions he gave were all things that the bot can understand in terms of formatting: complex exercises before simple ones, more reps for some exercises than others, and so on. These are essentially tweaks to the text that ChatGPT generates. And when this trainer, Colin Jenkins, says that the results were better than “most” trainers, he’s referring to people who post workouts on the internet but don’t really know how to write programs. Not exactly a high bar to clear.
I asked the bot to put together some simple programs, and it failed every test. First, how about a meet prep block for somebody about to do a weightlifting competition? That’s a straightforward job: You just need a lot of medium-to-heavy singles on the competition lifts, cut out most accessories, and make sure the last few days are nice and light to let the athlete recover and go in fresh. Coaches will debate the finer points, but I was willing to accept anything in the right ballpark.
So what did ChatGPT give me? The exact opposite of that. The competition lifts were only in there once a week, they were in triples rather than singles, and the week where you’re supposed to be recovering was the heaviest of all. Instead of cutting out unnecessary lifts, it programmed deadlifts at 90% (in sets of five!) three days out. If I did that before a meet, my coach would kill me.
Would it do any better with, say, a marathon program? Nope. It expects an intermediate runner to do a thirty-four mile run two weeks out. Normally you only go up to about 20, since a marathon is 26.2 miles and those longer runs are hell on your body.
Poking it a bit more, I managed to get a sorta-OK beginner marathon program, and a sorta-OK hypertrophy block for a powerlifter. (Not for a weightlifter, though: ChatGPT thinks it’s OK to do snatches in sets of eight.) Sometimes I was able to sniff out specific sources: It gave me a deadlift workout that combined a misunderstanding of one of Jim Wendler’s 5/3/1 structures with a misunderstanding of Mark Rippetoe’s Starting Strength. The result was not pretty.
Do AI workouts have a future?
So does something like ChatGPT have a future in the world of fitness? I would say yes, but not to design workouts or apply training knowledge. If you give it a structure, it could fill in a few blanks, maybe save coaches some typing.
There are people already using AI engines for workout programs, but in a way that is very different from ChatGPT. For example, WeightliftingAI uses programs designed by weightlifting coaches, and the bot adjusts your program based on factors like how you perform. Juggernaut AI does something similar for powerlifting. People who have used these apps sometimes complain about the day’s workout being harder or easier or more boring than they’d like, but overall they seem to produce coherent workouts that help people toward their goals.
The difference between these “AIs” and ChatGPT is that these algorithms were taught training principles and given instructions on how to adjust them. ChatGPT was just taught how to write text. These systems dedicate much of their logic to fatigue management; ChatGPT completely ignores fatigue management. A good coaching AI can’t write you a poem, but it “knows” when to put a little more weight on the bar.
You can also use ChatGPT cautiously to come up with ideas, like building a collection of grip exercises or remembering that tabatas can be a good structure for a quick workout. But when you’re using ChatGPT to generate ideas, you as a human need to be able to tell which ideas are good and which are bad. If a generated workout sucks, ask it for something else. If it tells you to do a brutal deadlift workout right before your weightlifting meet, don’t listen to it. If the 10-minute workout doesn’t add up to 10 minutes, give it a more specific structure and see if it can fill in the blanks.
To work with ChatGPT to make a successful workout, you need to have a training background yourself. That’s why it can’t replace a knowledgeable trainer: You pretty much have to be one to coax a good workout from it.