
If you happen to’ve been following my ChatGPT experiments, you most likely know I used OpenAI’s generative AI to purchase trainers and prepare for working half-marathons. Quick-forward to mid-October, and I accomplished three half-marathons in a few month, together with an official race.
I put on an Apple Watch SE 2, which helps me observe well being and train parameters. Naturally, I used it to document my progress in coaching for the half-marathon and throughout the three races. I had no cause to mistrust the stats it put out till a couple of days in the past. I accomplished an official race, which suggests I used to be being timed with knowledgeable race chip.
That’s how I found my Apple Watch could be mendacity to me about how briskly I’m working. What’s extra puzzling is that the watch recorded the identical working time because the official trackers.
Let’s begin at first. A half-marathon is normally known as 21K, brief for 21 kilometers (or 13 miles). The precise distance is 21.0975 kilometers (13 miles 192.5 yards), so I at all times be certain I am going over that 21.1 km mark whereas coaching.
The Apple Watch ran the newest steady watchOS model obtainable, not a beta launch. Additionally, I at all times take the iPhone 14 Professional with me, which runs the most recent steady iOS launch.
The coaching runs
As I elevated my mileage in response to the coaching plan that ChatGPT helped me fine-tune, I discovered that working distances over 15 km was getting simpler and simpler. Then, simply over a month in the past, I went for my first 21K run in 5 years. I had no expectations. I simply wished to see how I’d really feel getting previous it.
I’ll let you know that it wasn’t simple, and I spotted I had extra work to do. I figured that with a few month to go till the race I used to be coaching for, it wouldn’t be an issue.
However then my Apple Watch gave me stunning information. I managed to tug off an all-time private finest. I tracked earlier 21K races with the Apple Watch, so I’ve the historical past useful. The wearable informed me I completed the race in 1:56. That’s one hour and 56 minutes; I’ll be leaving the exact trip of this, as the additional seconds do not likely matter.
I used to be amazed at how snug the coaching and the 21K run was. ChatGPT coaching labored.
Two weeks later, I went for an additional 21K run. This time, I wished to check an precise technique for the race that was arising in one other two weeks. I ran that one in 2:06, in response to my Apple Watch. I wasn’t attempting to beat my earlier private finest. As a substitute, I used to be simply establishing the ultimate particulars for the massive race.
Quickly sufficient, that day got here, and my primary objective was to complete the race. I additionally set a objective to run the race in underneath two hours. If potential, I’d attempt to beat 1:55.
The official race
Come race day, I knew I wouldn’t need to maintain checking the Apple Watch to see my stats. Pacers with balloons hooked up to their backs would assist me inform how briskly I used to be working. Subsequently, I wished to finish the race between the 1:55 and a pair of:00 pacers. If I may beat the previous, that’d be nice.
For over 18km, I used to be properly forward of the two:00 pacers, however I wasn’t getting near the 1:55 of us. I believed I would push myself to succeed in them and go them on their left. Little did I do know that the seemingly endless flights of stairs alongside the ultimate stretch, which resembled small hills, would make that process unattainable.
I didn’t want to take a look at the Apple Watch to appreciate that I wouldn’t end the race in underneath two hours as the two:00 pacers handed me by. With some 200 meters to go, I glanced on the watch and noticed it informed me I may nonetheless finish the race in underneath 2:00. I struggled, and I completed the race with a time of 1:59, in response to the wearable. Mission achieved?

The Apple Watch stats
However then essentially the most uncommon factor occurred. The watch informed me I simply ran my quickest half-marathon, with a time of round 1:52. That appeared unattainable. I believed that possibly the two:00 pacers ran sooner than they had been alleged to, and that was why they handed me by.
A couple of hours later, I checked the official race time. It was 2:01, some 10 seconds greater than what the Apple Watch had informed me.
Surprisingly sufficient, the chip time was 1:59, matching the time the Apple Watch registered. Furthermore, each the official statistics and the Apple Watch gave me the identical race tempo. I in contrast it to the half-marathons I ran earlier, and I concluded that it was my quickest half-marathon regardless of the plain points with the time.
The conclusion appears to be that the Apple Watch algorithms may need some points measuring working stats. I can’t say the place the discrepancy comes from. Between 1:52 and 1:59, there are some 7 minutes of working. Greater than an additional kilometer. What’s unusual is that the watch did measure the right race time, 1:59, similar to the organizers.

This leads me to imagine that I used to be truly slower throughout my 21K coaching runs that preceded the race. It additionally makes me surprise if the 5K and 10K instances I’ve been experiencing previously few months had been correct. I saved beating my private bests for each distances throughout coaching.
Additionally, if the Apple Watch may be this improper about my race time, do I’ve to fret in regards to the different stats it tracks throughout a run? Like calorie estimates, coronary heart fee, and running-related stats that I would normally examine.
What’s sure is that my quest continues. I’ve used ChatGPT to comfortably run half-marathon races, and I’m not going to cease. I’ll maintain monitoring my progress, particularly throughout the future official races I plan to run. I’m even contemplating utilizing a distinct wearable. Or a distinct Apple Watch mannequin to see whether or not they’re extra correct.