Almost at the same time I found out that I got my spot in Tokyo Marathon 2025, Garmin announced that their Garmin Coach Plan now incIudes preparation for the full marathon. At that time I had different training/racing goals, but after my 2024 season ended, I decided to give it a shot and on October 1st, 2024, started using Garmin Coach’s Marathon Plan with target race being the Tokyo Marathon 2025.
However, on October 11th the program suddenly disappeared from the Garmin Connect (on the web, in the home screen), and trying to access it on the app caused an app crash. Interestingly, the plan seemed to be active, as when going to the Training & Planning > Garmin Coach Plans, it was visible there. However, it was not showing further workouts planned for the current week – for the remaining Saturday and Sunday, the calendar icons were ‘dots’ (which usually mean a workout is scheduled, but Garmin did not decide the details), and trying to see the upcoming week crashed the page.
So I went ahead and created the plan anew (by “ending” the current plan, as it was shown as still active) with the following parameters:
- Five days a week (with days off on Mon and Fri, long run days being Sat and Sun)
- Time goal of 2:59:59
- Current average running distance: 40+ km
- Current average pace: 4:55 min/km (which was somewhat true before Garmin started to slow me down to 5:15 😉
My plan was to continue doing gym work on Mon and Fri, so these were not actual couch days 🙂
On November 7th, plan disappeared again. I set it up using same params as above, except kept average pace of 5:09 (somehow filled in by default). By the way, it still had my original sub-3 time goal.
On November 9th, Garmin coach removed all the upcoming workouts and, though not crashing this time, was showing “Workout – Stay tuned for details” for an upcoming day. Situation did not improve the day after, basically stopping the training. Restarting plan again (this time, average pace was set to 5:07).
On November 10th, I decided to make some changes to the plan (added extra day of training on Monday). On the next day (and many times after that) I noticed that watch and app/web went completely out of sync, with e.g. watch suggesting 0:21h of recovery run and app showing 9x 10-secs sprints with 3-minute rests (0:51h in total).
Upcoming weeks were ridden with firmware updates, subsequent plan wipeouts, and no interval work at all (absolute majority of runs being in Z2). Even if initial plan of the week had some interval work planned, it was endlessly pushed further and never happened.
I posted a few planned/executed schedules below- note that execution scores were close to perfect, yet the final week plan was completely different from initial schedule.
 |  |
 |  |
 |  |
 |  |
If anything, I would call Week 16 the least productive week so far. It probably could be called a recovery week with two rest days, but the way how the workouts were scheduled I doubt it a bit.
On January 2nd, 2025 (Thursday), I woke up with 2h recovery time on my watch, and the plan was still showing the 40-minute Z2 run. After the run (pace 5:04, avg HR – 135, compliance 81%), Max HR was adjusted to 174 and Recovery time set to 23 hours.
I did my run in the morning on purpose – I wanted to wait until the recovery time would be 0h, so I could see the impact of the abovementioned 40-minute Z2 run. And guess what – the ‘original’ workout for Friday (Sprints) was replaced by 29-minute Z1 recovery run (as if there was something to recover from).
Also, on the same day my Stryd Critical Power was downgraded by 4% (and bringing my Tokyo marathon target down by 6 minutes). It definitely did not add optimism to my training, but the good thing is that soon I was able to test all the predictions in at least for 21K.
 |  |
Week 17 on paper looked great from the workload perspective (and also it is touted as a start of Peak Phase), however after a long run on Monday I was prescribed 32-minute recovery on Tuesday (that I did on the treadmill, as usual) and then guess what? Plan was wiped out, with Connect app showing rest days until the marathon day, Garmin Connect on the web either showing that there’s no active plan or active plan with one rest day (depending on what view you’re looking at), and Garmin watch referring to Garmin Connect app. I don’t remember any firmware updates happening (and watch still has the 21.20), so I have no clue what caused this to happen. So, with less than eight weeks left to go until the marathon, I restarted the plan again.
And this time, suggested pace was 5:13 min/km (I put that back to to 5:09) and left all other parameters same as before (including now the fancy goal of sub-3). Interestingly, plan configurator did not show me F^3 21K race anymore (which kind of makes sense, as there are just two weeks left to it). And of course it had that good old sprint workout scheduled for the next day, which ironically did happen (as my usual training route was icy and slippery). Also long run was planned for Friday (even with explicitly saying that I prefer long runs on weekend), with Saturday having 16-minute Z2 run and Sunday being a day-off (which means the settings were completely ignored). Yet I was not stressing that much over it, as my past experience showed that initial plan changes drastically in the course of the week.
On the same day, after checking Garmin public beta announcements, I saw that version 22.12 was out, that will offer supplemental strength workouts for Garmin Run Coach Plans. So decided to install it manually, as hey, what worst could happen (plan was gone anyway). Plan was wiped out as usual, so I set it up anew. And interestingly, this time it generated different workouts than a few hours before, so obviously there was some change in the algorithm. Fingers crossed.
On January 9th, I added strength training workout option (chose full gym, the other option being bodyweight) to the Tokyo Plan. It immediately recalculated the plan by eating up a bit into the running time, but since strength training is extremely beneficial to runners of all age groups, it was not a terrible tradeoff.
Interestingly, the web version did not show the details on what exercises are in the gym workout – they are only visible in Garmin Connect app (and Garmin watch, accompanied with how-to videos for some of them).
Also, it seems that with this newest firmware version the quality of training plan has vastly improved with bigger variety of workouts included. If it remains at that level after “auto-adjustments”, that may indicate a great leap in usability of Garmin Coach in marathon training.
 |  |
On January 16th (mid-week 18) I installed version 22.14 – an action that wiped plan again. Interestingly, the plan recreated was exactly similar to the plan before the wipe, so at least it is consistent and not so much frustrating as before, when totally different plan was offered after re-creating the plan.
 |  |
Since the beginning of Week 19, my watch kept having it’s own opinion on training and refusing to sync with app/web (e.g. suggesting sprint workouts when app/web were suggesting recovery or rest days) even if multiple sync requests were manually triggered, including Bluetooth on/off on the phone, etc.
I chose to trust app/web version for training, as the comments next to workouts seemed to be more relevant (e.g. saying ‘This easy workout should help you perform your best in tomorrow’s event.’ a day before the race, kind of showing that it knows that I’m racing tomorrow).
Potential problem could be that apparently the watch did not have my 21K race identified/synced as a proper event, as Saturday morning it showed a regular Morning Report with all the health data instead of two-screen greeting that it shows on a race day.
Interestingly, Garmin showed me peaking Thursday and Friday, and evaluated my status as Improving after the race.
On Tuesday, January 28th Garmin devices (all, not just beta program participants) experienced a major issue with activities requiring GPS signal – when starting such activity, devices would go to infinite boot loop with only factory reset being an option. Not sure if related to that, marathon training program was wiped from the watch (yet remained in app/web). It kind of returned after I synced ‘Tokyo marathon’ event with the watch, but it was different from what was in an app (1:26h run in the watch vs. 0:58h run in an app, though both had Pre-run Activation gym workout). I decided to go with the watch version as I felt like I’m missing my mileage, completed pre-run workout, got dressed, went out the door and then… There was no run workout for that day. And this time, all the devices were in sync. To be honest, I could not understand this shift in a training plan, as I was fully rested (0h recovery time even after gym workout), etc. but who am I to question coach decisions 🥲
Wednesday runs in app/web and watch were materially different again, went with the watch recommendation. Also, installed firmware update 22.18 and was surprised that plan was not wiped out.
On February 20th, i.e. less than two weeks left to the race, I installed update 22.22 and guess what – plan was wiped out again. Yet this time, it was not possible to re-create it anew (due to event being too close), so I continued following daily workout suggestions (plus Garmin’s Jetlag advisor) and hoped that taper will go just fine. Also the watch showed me ‘Let’s get ready for the race’ message, so maybe it planned my taper correctly after all 🙂
Finishing time predictions
With 10 weeks left to Tokyo marathon (December 22nd, 2024), I decided to check on what marathon finish time Garmin thinks is reachable in its Race Predictor feature. Suggestion was 3:23:52 (and half marathon time 1:32:26, which I will be able to test in F^3 21K run in just five weeks) and it is quite far from the goal I set in the plan. However, Garmin does nothing to inform me to help with expectation management. Whether this 3:20+ hour goal is realistically achievable or not, I will find out in actual Tokyo Marathon (and I’ll be checking in to check if it changes every week), however it feels to be quite close to my actual form. Also, Stryd Race Calculator for Tokyo Marathon (using verified course) kind of backs my (and Garmin’s) feel by suggesting 3:24:34 +/- 4:05 finishing time. So as of December 22nd, 2024, I can *almost* break 3:20h on a good day (which is disappointing a bit, but that’s the price of testing different training strategies that not necessarily are always working in favor of athlete’s goals).
On the Week 16, Garmin became slightly more optimistic with predictions and suggested I could do 3:23:00 (1:32:18 half). Stryd remained basically the same with 3:24:33 +/- 5:00 min time prediction (and 1:35:29 +/- 2:00 for F^3 half with uploaded course).
In the beginning of Week 17, Garmin’s race forecasts remained largely the same (3:22:42 marathon, 1:32:16 half) while Stryd’s forecast was significantly decreased in relation to decrease in Critical Power, and shown as 3:30:57 +/- 5:00 min for Tokyo and 1:38:34 +/- 2:00 min for F^3.
For Week 18, Stryd predictions were almost the same as in Week 17 – Tokyo at 3:31:16 (+/- 5min) and F^3 at 1:38:29 (+/- 2min), yet Garmin became much more optimistic, forecasting marathon time to be 3:17:54 and 21K to be 1:31:12.
Further marathon time predictions (from week 20) can be found in a table below
| Week # | Garmin prediction | Stryd prediction | Notes |
|---|---|---|---|
| Week 20 | 3:10:22 | 3:18:12 (+/- 4 min) | Week after 21K race, when CP was updated |
| Week 21 | 3:09:04 | 3:21:25 (+/- 4 min) | |
| Week 22 | 3:07:49 | 3:20:51 (+/- 4 min) | |
| Week 23 | 3:06:41 | 3:20:51 (+/- 4 min) | |
| Week 24 | 3:05:06 | 3:21:24 (+/- 4 min) | Last week before the race |
21K Test Race (F^3 Lake Half Marathon)
21K race went better than expected and I finished in 1:30:01 (five years ago it would be disappointing, and now just very funny). Started feeling fatigue (both mental and physical) with two miles left and let the 1:30h pacer go about a half mile to the finish line.
Race time exceeded most recent predictions – 1:32:16 by Garmin and 1:36:34 by Stryd (optimistic, with 2 mins subtracted).
Post race, Stryd immediately upped my Critical Power by 3%, from 285W to 293W (still not close to 302W that I had until the end of October 2024).
Ultimate Plan Test – Tokyo Marathon 2025
Since the plan for Tokyo Marathon was just to finish it and get my 5th of 6 WMM stars, I did’t stress out while experiencing all this conundrum with updates, plan wipeouts, absence of any sort of intervals, etc.
I didn’t have any really long runs (the longest one during my preparation was 2:04h and a handful of 1:30-ish runs), so I did not know how will I feel at hour 3, but I was telling to myself that if I’ll do it under 3:20h – I will be happy.
All in all, I finished in 3:17:44 and had fun on the course (met my compatriot during the warmup and we were running together from start to finish – a great experience).
Yet if asked if I recommend using Garmin Coach for proper marathon training, I would say certainly not, or at least not if you’re member of the Beta program. Being in software business for years, I thought I have seen everything in terms of poor software quality, but this experience with Garmin Coach in Beta set the quality bar to the new lows.
