I Asked ChatGTP to Help Me Build Muscle (as an Exercise Scientist). Here's What Happened...

Two months ago, OpenAI released ChatGTP.

It's an artificial intelligence with "advanced language generation". You can chat with the AI, and it answers you like a (very smart) human would.

The AI already has over 100 million users, making it the fastest-growing consumer app in history. It knows most of the Internet, and can answer just about any question.

But is it always right?

I have been a coach and a lifter for over 20 years, and a trainer for the Canadian Forces.

As a coach and exercise scientist, I wanted to find out if ChatGTP would cost me my job.

Should you fire your personal trainer?

To find out, I asked ChatGTP a few questions.

Common questions we get at Dr. Muscle, as well as more advanced ones. Those included:

I want to get big
How much protein should I eat?
What causes muscle hypertrophy?

Here are the results...

Q: I want to get big

Answer from ChatGTP:

If you're referring to building muscle mass and getting stronger, here are some general tips that may help you reach your goal:

1. Consume enough calories: To build muscle, you need to consume more calories than your body burns. Focus on eating plenty of protein, carbohydrates, and healthy fats.

2. Strength training: Focus on compound exercises such as squats, deadlifts, bench press, and rows to work multiple muscle groups at once.

3. Progressive overload: Gradually increase the weight you lift over time to continually challenge your muscles.

4. Adequate recovery: Give your muscles time to recover between workouts, this can include getting enough sleep, hydration, and proper nutrition.

5. Consistency: Stick to a routine and be consistent with your training and nutrition.

It's also important to consult a doctor or a qualified fitness professional to see if your goals are safe and achievable, and to get a personalized workout and nutrition plan.

Comments and rating

I was actually surprised by the accuracy of that answer.

First, the AI understood that "get big" meant in fact "build muscle mass".

Second, the variables it listed may very well be the most important ones to keep in mind when you're trying to build muscle.

We wrote about that extensively on this blog, and you may recognise many from Dr. Cholewa's articles:

I especially liked that ChatGTP mentioned progressive overload. It's the main thing you should keep in mind to make progress. I wrote about it at length in:

Overall, I would rate this answer a 5/5. It's better than a lot of the advice I see online from well-meaning, but somewhat underqualified trainers.

Q: How much protein should I eat?

Answer from ChatGTP:

The recommended daily intake of protein can vary depending on several factors such as age, sex, weight, and level of physical activity. As a general guideline, the following can be used as a starting point:

- Sedentary adults: 0.8 grams of protein per kilogram of body weight
- Active adults: 1.2-1.7 grams of protein per kilogram of body weight
- Athletes or bodybuilders: 1.6-2.2 grams of protein per kilogram of body weight

For example, a sedentary person who weighs 70 kg (154 lbs) needs 56 grams of protein per day (70 x 0.8 = 56). However, these are just estimates and your individual protein needs may be different.

It is always a good idea to consult a healthcare professional for personalized recommendations based on your specific health and nutritional needs.

Comments and rating

Again, this answer is in line with the scientific literature (e.g. Iraki et al. 2019). However, I think a great coach may be able to offer additional nuance.

While the scientific litterature does indeed support intakes up to 2.2 grams of protein per kg, some coaches and bodybuilders recommend higher intakes, especially during cutting phases.

For example, in The Protein Book, infamous physiologist and coach Lyle McDonald recommends intakes of up to 3 grams per kg for strength athletes. This is based on years of experience and an OCD-style review of the litterature.

(The book has over 400 references and is one of the most impressive synthesis of the evidence I have had the pleasure to read).

In an interview, Lyle noted that "this can go up a bit during dieting of course". He also said:

Empirically, many athletes feel that gains are better with higher protein intakes, say 3.3 grams per kilogram of body weight (1.5 grams per pound).

It may be that, when you add training and increase overall protein turnover (synthesis and breakdown), the above values don’t hold and will have to be increased. It’s possible that only looking at skeletal muscle protein synthesis is missing some parts of the overall picture, there are other pathways important to athletes that use protein which will increase requirements. Given how EAA digest, compared to whole proteins for example, it’s also eminently possible that the digestion pattern of whole proteins makes the above research inapplicable in the first place.

Finally, it’s possible that all bodybuilders are deluding themselves about their need for higher protein intakes although it’s a little hard to dismiss 4 decades of empirical observations out of hand like that. A lot of what bodybuilders have found to work has been subsequently validated by research, this may be another of those areas.

Higher intakes have also been studied (Antonio et al. 2015), with the authors concluding that:

"A high protein diet (3.4 g/kg/d) in conjunction with a heavy resistance-training program may confer benefits with regards to body composition. Furthermore, there is no evidence that consuming a high protein diet has any deleterious effects."

Bottom line, I would rate this answer a 4/5.

There may be some benefit of higher intakes for some lifters. ChatGTP spits out the correct evidence-based answer, but lacks the nuance a great coach would be able to provide.

As the AI rightly pointed out, it is always a good idea to consult a healthcare professional for personalized recommendations.

Q: What causes muscle hypertrophy?

Answer from ChatGTP:

Muscle hypertrophy, or the increase in size and mass of skeletal muscle tissue, is typically caused by an increase in the size and number of muscle fibers. This can occur as a result of various forms of exercise or physical activity that involve resistance or weight training, such as weightlifting, bodybuilding, or other forms of strength training.

During resistance training, the muscle fibers are subjected to mechanical stress, which causes small micro-tears in the muscle fibers. These micro-tears stimulate the activation of satellite cells, which are responsible for repairing and regenerating damaged muscle fibers. Over time, this process of muscle damage and repair results in the growth and hypertrophy of muscle fibers, as they become larger and more numerous.

In addition to mechanical stress, muscle hypertrophy can also be influenced by factors such as hormone levels, genetics, and nutritional status. For example, testosterone and growth hormone are two hormones that are known to play a key role in muscle hypertrophy, while adequate protein intake is important for providing the building blocks necessary for muscle repair and growth.

Comments and rating

I was hoping to trick ChatGTP with that one. It worked, to some extend.

That's because our understanding of muscle hypertrophy has changed over time.

So the AI was mostly right. With some exceptions...

Most scientists would agree that muscle hypertrophy is caused by an increase in the size of muscle fibers, not their numbers (Kraemer et al. 1998).
As I wrote in 2018, muscle damage probably does not cause muscle hypertrophy.

With that said, the other factors the AI mentioned are all on point. So, I would rate this answer 4/5.

Wrapping up: Should you replace your coach with AI?

I asked ChatGTP!

Here's what it said:

In conclusion, ChatGPT proved to be a worthy contender in the world of personal training and nutrition. It provided accurate and comprehensive advice that was in line with scientific literature. While it may not be able to offer the same level of personalization and nuance as a human coach, it's a great starting point for anyone looking to build muscle or maintain a healthy diet.

So, should you fire your personal trainer, coach, and dietician in favor of ChatGPT? Well, not quite yet. While ChatGPT is a valuable resource, it's always wise to consult a qualified professional for personalized recommendations. After all, a human coach can offer encouragement, motivation, and that extra push to help you reach your goals.

In the end, it's a battle of man versus machine, and both have their pros and cons. But one thing is for sure: the future of personal training and nutrition is looking pretty darn impressive. So, whether you choose to go the AI route or stick with the good old-fashioned human touch, don't forget to train hard, eat well, and most importantly, have fun!

That's a darn good recap.

I would also add that only a human coach can:

Help you master advanced exercise execution, form, and technique
Bond with you and make you feel seen at a deep level

Both of which are key components of a successful fitness journey.

So, in conclusion...

As a coach and exercise scientist with over 20 years of experience, I predict that human coaches are here to stay.

AI apps like ChatGTP are likely to make your coach more effective and efficient. But I don't see AI replacing the human touch anytime soon.

And until AIs are perfect, you'll still need a human coach to get personalized recommendations that are up to date and 100% accurate.

So, fellow trainers: our job may be safe... for now. Phew!

Want to learn more? As part of this series on AI coaching, I asked ChatGTP to write a full guide on building muscle. Again, the AI was surprisingly accurate.