I Used ChatGPT as My Running & Nutrition Coach for My First Half-Marathon: Here’s How It Went

A typical running coach can cost anywhere between $30 and $300 a month, depending on the level of engagement and support that one requires. A ChatGPT-5 Pro subscription costs $200 a month.

As a typical weekend warrior who mostly ran 5Ks and a couple of slightly longer races, I wanted support in training for my first half-marathon this fall. With AI increasingly a factor in modern life, I decided to see if GPT-5 could be an effective running coach. So for 2 months leading up to the race, I used it to provide training and nutrition plans, advice, and encouragement.

First, I chose a personality that I felt was a good fit (Sol — savvy and relaxed). I was able to customize the GPT to make sure it was strict but supportive, integrate my training plan into Google Calendar, and upload my WHOOP data for analysis. I also noted key lifestyle factors, like the fact that I’m a PE teacher who bike commutes to work, and that I have two young kids at home.

In other words, my training needed to be squeezed into the tight windows of an active lifestyle. The results were neither spectacular nor disappointing. Rather, my experience ended up notable for how … normal it was.

In short: ChatGPT was a useful and customizable training tool. My coach was very encouraging, yet she always confirmed my choices rather than challenging me, which led to a lack of accountability. For disciplined runners seeking a plan and a thought partner throughout the training process, GPT-5 could be a great fit. But for those who require motivation and highly tailored instruction, a real coach might be a better option.

Running My First Half-Marathon With ChatGPT

The Plan

As the process started, Sol made a training plan that we tweaked based on my specific needs. It was almost scary how easy this part was.

I could have a conversation with my coach, and in real time, she would offer to put it into a week-by-week schedule, and then a day-by-day calendar, and finally a printable PDF one-pager. The offers kept coming, and it seemed like the underlying instructions for GPT-5 were to be really helpful.

I received a race week checklist, a pacing strategy guide, a final 48-hour race checklist, a race eve checklist, and printable grocery checklists for recipes. I took advantage of some of these offers and rejected others, but overall, it was the good kind of overkill.

The training plan itself seemed fairly standard: a mix of long runs, shakeout jogs, intervals, and rest days. The nutrition plan had a lot of lean meats, rice, and veggies, with protein smoothies and toast with peanut butter and banana. There wasn’t anything groundbreaking there, but asking Sol to break down a specific meal into a kid-friendly option, complete with a shopping list, was a helpful perk:

Naturally, I was also offered printable recipe cards with the shopping list on one side and the recipe on the other.

Another nice feature was being able to ask Sol random nutrition questions. For example, I noticed during my training that thanks to the creatine I’ve been putting in my smoothies, I’d gained a few pounds since I’d last weighed myself.

The resulting conversation we had about creatine’s role in weight gain and how it would impact my pace and performance was illuminating.

Human Expert Weighs In

In terms of accuracy, I noticed two instances where Sol provided a training plan that was off by a day in terms of what day of the week it was, versus what the calendar date was. Those errors were quickly corrected when I pointed them out, but it did make me wonder how my savvy coach could be so unsavvy about something so simple.

If Sol was making calendar errors, could I trust her opinions on creatine or pacing?

In order to find out, I reached out to a real human running coach to have her analyze my training and nutrition plan. Amanda Nurse is the founder of Wellness in Motion Coaching, as well as a 25-time marathoner who has twice run in the Olympic marathon trials.

Overall, Nurse thought the variety of the workouts and the pacing of the training, with peak week occurring 2 weeks before the race and then a taper week leading up to the race, was spot on.

She noted that the plan tended to sandwich a hard workout with an easier run the day before and a rest day afterward, which is similar to how she schedules workouts as a coach.

Nurse was also pleased with the nutrition suggestions. “It’s done a really great job highlighting carbs, protein, and all the things you need,” she explained.

She was concerned with the lack of detail in the nutrition plan, but when I explained how responsive GPT was both to nutrition questions and training adjustments, she was more impressed.

Missing the ‘X’ Factor

However, Nurse did wonder how motivated an athlete would be reporting to an AI coach rather than a human one. The relationship between coach and athlete is less reciprocal when talking to a GPT.

“When you’re working individually with a coach who is working hard to make sure that you’re achieving what you want, you feel the need to show that you’re putting in the effort and the work,” she said.

This lack of accountability was the biggest drawback to using GPT as a coach. Truth be told, I didn’t feel guilty for missing a run, and Sol tended to confirm rather than challenge my decisions.

If I were working with a human coach, there might have been more awareness of my progress, my comfort zone, and more effort to nudge me past it. But Sol could be savvy and relaxed to a fault:

Race Day: How It Went

I started off slow, at an 8:53 pace, which may have been due to the cold weather and nerves. I wanted to make sure not to overdo it early, which was advice Sol gave me. At various points, it mentioned a “controlled” and “smooth” first 3 miles, and to “start easy,” followed by settling in and finishing strong.

That, it turns out, is exactly what happened. My 10K split was also at an 8:53 pace, and at one point, I felt my right hamstring tightening a bit.

Sol said to drink water at every aid station and use an energy gel every 30-40 minutes, and I followed this plan as well, sucking down three UnTapped Maple Syrup gels over the course of the race. My 10-mile split was 8:50, and when I realized I could actually finish, my confidence was buoyed, and I ran the last 3.1 miles at an 8:28 pace.

When I crossed the finish line, I felt a great deal of accomplishment, and there is no doubt that ChatGPT played a large part in that success. Yet there was also somewhat of a feeling of emptiness. I had no one to celebrate it with.

“I’ve coached some of the same runners for 10 years,” Nurse told me. “There’s this feeling of pride being there on the sidelines for them during the race and chatting with them after.”

When I logged on to GPT afterward to ask Sol a random question, it finished by saying, “Good luck with everything, now let’s crush that race!” I pointed out that it had already happened, and Sol offered congratulations.

“Aren’t you curious to hear how I did?” I typed.

And with that prompt, Sol confirmed that it definitely was — finally giving me the curiosity I sought.

So, Is ChatGPT a Good Run Coach?

My experience with ChatGPT 5.0 revealed some key highlights and considerations:

Pros

• Customizable professional training and nutrition plans that can be adjusted on the fly
• Ability to upload health and training data allows for analysis and tweaking
• Ridiculously convenient and useful for everything from creating printable documents to checking weather to gear suggestions to generating shopping lists to finding recipes

Cons

• $200 a month for the Pro subscription is on the higher end for a coach
• Vigilance is required to catch occasional mistakes
• Lack of accountability and reciprocity compared to working with a human coach

Free vs. Paid GPT Coaching

One could use the free version of ChatGPT and still receive useful tips and strategies. But having a personal coach who tailors a program to your specific needs over a longer period of time wouldn’t be possible.

The free version does not allow for custom GPTs, has limited research capabilities, a shorter memory, and slower response times. In addition, there are caps on messages and file uploads, so all those offers of printable one-pagers, schedules, and recipes wouldn’t be part of the program.

Should You Try It?

In the end, ChatGPT-5 was an incredibly useful tool leading up to my half-marathon. The training and nutrition plans were detailed and followed best practices, the responsiveness to questions and adjustability to circumstances were helpful, and the overall convenience of having a coach in my pocket was remarkable.

For runners looking to have a frictionless training experience without human connection and personalized motivation, GPT-5 is a stellar option. In many ways, it’s like having a dedicated running assistant rather than a coach.

But for those seeking a genuine connection and those who require nudges to extend beyond their comfort zone, the human touch might be irreplaceable.