I let ChatGPT program me a five-move muscle-building workout — and the results were surprisingly impressive

The AI got very close to good advice, but it can't replace the expertise of a qualified personal trainer

Man holding a plank position
(Image credit: Getty Images)

Artificial Intelligence (AI) — a computer that mimics human Intelligence — has become a staple of most sci-fi movies, but what does that have to do with exercise? 

Last week, a team of researchers released ChatGPT, a conversational AI that can answer questions. So I wanted to see if it could create a practical and safe workout to build muscle at home. 

It started with a simple question — what would be a good five-move workout to build muscle? I was half expecting it to suggest picking up a set of adjustable dumbbells and attempting an Arnold Schwarzenegger-style bodybuilding workout. But that's not what happened. 

Instead, ChatGPT designed what looked like a fairly reasonable bodyweight routine, except for the final move — bicep curls — which do require weights. The system accurately described how to do a plank and the proper form for squats. On the surface, there was nothing wrong with its advice, either: 

  1. Squats: Stand with your feet shoulder-width apart and extend your arms in front of you for balance. Lower your body as if you are sitting back into a chair, keeping your weight in your heels and your back straight. Push through your heels to return to the starting position.
  2. Push-ups: Start in a plank position with your hands placed slightly wider than shoulder-width apart and your body in a straight line from head to toe. Lower your body until your chest touches the ground, then push back up to the starting position.
  3. Lunges: Stand with your feet hip-width apart and take a large step forward with one leg. Lower your body until your thigh is parallel to the ground and your back knee is just above the ground. Push through your front heel to return to the starting position, then repeat on the other side.
  4. Plank: Start in a push-up position, but instead of balancing on your hands, rest on your forearms. Keep your body in a straight line from head to toe and hold the position for 30-60 seconds.
  5. Bicep curls: Stand with your feet hip-width apart and hold a pair of dumbbells at your sides with your palms facing forward. Curl the dumbbells up towards your shoulders, keeping your elbows close to your sides. Lower the dumbbells back to the starting position and repeat.

Remember to start with a light weight and gradually increase the weight as you get stronger. It's also important to warm up before you begin any workout, and to stretch after you finish.

Even though I hadn't asked for this, it even offered safety advice and suggested following the progressive overload technique to increase the weight as you gradually get stronger. Although, it didn't understand that guidance only applied to the bicep curls. 

As impressive as it seems, it's not the most exciting workout; these are fundamental exercises that most people have heard of. Putting them together as a routine is practical, but it only shows a little knowledge. So, we asked something more specific; can you build core strength just using sit-ups?

Screenshot of ChatGPT answering whether you can build core strength with sit-ups alone

(Image credit: Future)

The AI correctly noted that sit-ups are one way to build core strength, but they're not the only way. ChatGPT then suggested several other core strengthening exercises, like planks, Russian twists, and bird dogs. So far, the AI is doing a troublingly good job.

But does it really understand what it's suggesting? What if I asked it to create a nine-hour arm workout; would it know that's a bad idea that could lead to overtraining, or would it do as I asked? Those looking for a mammoth arm day session will be disappointed, as the AI basically said no.

It is not recommended to do a nine-hour workout to build arm muscle. In fact, a workout of that length could be detrimental to your health and fitness goals.

First and foremost, your body needs time to rest and recover between workouts. When you lift weights, you create tiny tears in your muscle fibers, which your body then repairs during rest periods. This is what ultimately leads to muscle growth and strength gains. If you don't give your body enough time to rest and recover, you may actually hinder your progress and increase your risk of injury.

Additionally, a nine-hour workout could lead to overtraining, which is when you do more exercise than your body can handle. Symptoms of overtraining include fatigue, irritability, and a decrease in performance. Over time, overtraining can lead to serious health problems, such as immune dysfunction, hormonal imbalances, and increased risk of injury.

It's important to find a balance in your workout routine that allows you to challenge your muscles without overdoing it. A typical weightlifting routine might include 3-4 days of strength training per week, with each workout lasting 45-60 minutes. This allows for adequate rest and recovery time between sessions.

Remember to listen to your body and pay attention to how you feel during and after your workouts. If you're experiencing any symptoms of overtraining, it's important to adjust your routine and give your body the rest it needs.

It's reassuring that you can't use AI to create unsafe or harmful workouts. Still, much of my time as a fitness journalist is spent working with personal trainers to help people find practical, accessible exercises you can do at home or the gym. So far, ChatGPT is after my job. So, I took another angle instead.

Screenshot of ChatGPT answering how does Chris Hemsworth build muscle

(Image credit: Future)

When asked 'how does Chris Hemsworth build muscle?', the AI responded: "I'm not sure how Chris Hemsworth specifically builds muscle, as I am a large language model trained by OpenAI and do not have access to personal information about specific individuals."

But we do know how Chris Hemsworth develops muscle for his superhero movie roles because we asked his trainer. Hemsworth's friend and Program Director at Centr, Luke Zocchi, told us that Hemsworth uses time-efficient compound exercises to build muscle and burn fat.

Could ChatGPT give actual advice, though, rather than universal guidance? When you're just starting out, it's hard to know which weight to lift. So that's what I decided to ask next; which dumbbell weight should I lift?

It's difficult for me to provide a specific answer without knowing more about your fitness level and goals. The best way to determine the appropriate weight for you is to consult with a fitness professional or to start with a lower weight and gradually increase the weight as you become stronger.

This was a relief for me, but it also shows that AI can't replace the expertise of a qualified personal trainer. If you're after an expert-led routine, you can use this personal trainer's beginner gym workout to build muscle.

Just be sure to use one of the best protein powders for weight loss to help your body repair and grow your muscles after your workout. 

James Frew
Fitness Editor

James is a London-based journalist and Fitness Editor at Fit&Well. He has over five years experience in fitness tech, including time spent as the Buyer’s Guide Editor and Staff Writer at technology publication MakeUseOf. In 2014 he was diagnosed with a chronic health condition, which spurred his interest in health, fitness, and lifestyle management.

In the years since, he has become a devoted meditator, experimented with workout styles and exercises, and used various gadgets to monitor his health. In recent times, James has been absorbed by the intersection between mental health, fitness, sustainability, and environmentalism. When not concerning himself with health and technology, James can be found excitedly checking out each week’s New Music Friday releases.