Why Your Garmin Stops Logging Mid-Squat-Day

Last November, my Fenix 7 stopped logging mid-squat-day. No alert. No error. No vibration. The rep counter just stopped advancing while I was three sets into 5x5 back squats.

I noticed because I was watching it. The screen had a number on it that did not change while I did the work. I finished the session. I opened Garmin Connect on my phone after dinner. I spent six minutes editing rep counts so the activity didn’t look like nonsense.

If you’ve worn a Garmin to the gym for any length of time, you’ve probably had a version of this happen. Maybe yours stopped at minute 47. Maybe at set 18. Maybe halfway through a Tabata block. The cap is real, the silence around it is real, and Garmin’s documentation does not name it.

Here is what is actually going on.

What you observe

Garmin’s native Strength activity has a documented design and an undocumented limit. The documented design is what you read about in the manual: tap Strength, the watch starts a timer, the accelerometer counts reps when you set the bar down between attempts, you tag the exercise from a list, you save and sync.

The undocumented part is what happens when the session runs long. Once an active strength activity runs long enough, depending on your watch model, firmware version, and what other activity types are competing for resources, the rep counter quietly stops registering. Reports cluster around the 45 to 60 minute mark, but the threshold isn’t fixed. Some users report heart rate continues to record fine. Some report the timer keeps ticking. The activity still shows “in progress” on the watch face. But the rep numbers stop moving, and any sets you log after that point either fail to save or save with rep counts that bear no relation to what you actually did.

If you don’t catch it during the session (most people don’t, because you’re lifting and not staring at your wrist), here is how it shows up later in Garmin Connect:

• Sets logged after the cap appear with 0 reps, or with the rep count from your last successful set duplicated forward
• Total reps for the session under-count by 20 to 50 percent versus what you actually did
• The exercise breakdown looks “tidy” in a way that’s wrong, your last 4 exercises all show identical set counts
• Some sessions truncate entirely, the activity shows 35 minutes of duration when you trained for 65

The fix from Garmin’s side is the same advice every help thread converges on: edit it manually in Connect.

Why it happens

The cap isn’t a bug. It’s a memory budget.

Connect IQ apps and native activity types share a fixed amount of RAM on the watch. The exact figure varies by model: a Forerunner 245 has roughly 64 KB available to the active activity, a Fenix 7 closer to 128 KB, an Epix 2 Pro can climb higher. The native Strength activity allocates a buffer for set data, exercise tags, heart rate samples, and the rep-detection state machine. When that buffer fills, the watch stops accepting new sets to protect the activity from corrupting on save.

What it does NOT do is tell you. No on-screen warning, no vibration, no documented behavior in any Garmin manual. The cap is a graceful failure from a firmware engineer’s perspective and a silent failure from a lifter’s perspective. Those are the same event with two different audiences in mind.

Garmin’s priorities make sense if you understand who their default user is. The native Strength activity was scoped for someone who lifts for 30 to 45 minutes, hits 4 to 6 exercises, logs maybe 20 sets total. That’s a reasonable median for a fitness-first watch sold mostly to runners and triathletes.

If you lift the way most people who landed on this article lift, programmed 5x5 or 5/3/1 or PHAT, 75 to 90 minutes a session, 8 to 10 exercises, 35 to 50 sets, you’re past the design envelope. The watch isn’t broken. The use case wasn’t budgeted for.

Four ways to work around it

1. Manual edit in Garmin Connect

The most common fix is post-hoc cleanup. After the session, open Garmin Connect on your phone, find the activity, tap into it, edit the exercise list, manually fix rep counts, manually add the missing sets. It works. It takes 5 to 10 minutes per session if you have a clear memory of what you did. It scales badly if you train 4 to 6 days a week, the cleanup tax compounds, and you eventually stop bothering. The data on Connect drifts away from the data in your head.

2. Save mid-session, start a new activity

Some lifters end the activity at the 40-minute mark, save it, then start a fresh Strength activity for the rest. This avoids the silent cap because the buffer resets between activities. The cost is two activities in Connect for one workout, broken Training Load attribution, and a noticeable break in wrist HR continuity. Functional, ugly.

3. Switch to a third-party Connect IQ app that writes its own FIT activity

A handful of CIQ apps exist for strength training that don’t share the native Strength activity’s memory budget. They write their own data structures, manage their own buffers, and emit a FIT activity at session end through the standard FIT-import path Garmin uses for third-party devices. Hevy applied for the cloud API equivalent of this and got blocked. The CIQ FIT route is different, it goes through the same channel Wahoo, Suunto, and Coros depend on, which Garmin can’t deprecate without breaking their cycling-computer partnerships. The architecture is detailed in how Rack writes real Garmin activities.

4. Use a phone-only app and skip the watch

Hevy, Strong, Fitbod, the lineup of phone-first logging apps. They work fine for rep counting and don’t hit the cap, but you lose the watch as the input device, lose the per-exercise heart rate data your Garmin is already recording, and lose the FIT activity in Connect entirely. The watch becomes a heart rate monitor and not much else.

How Rack handles long sessions

Rack is the third-party CIQ app I built after that mid-squat-day silence. The watch app uses its own memory budget, scaled to the actual length of a programmed lifting session, and writes a single standard FIT activity to your watch at the end. The CIQ app handles set storage, the iPhone companion holds the deep history (PRs, plate calculator, program builder), and BLE keeps the two in sync set by set.

When the session ends, the FIT file lands in Garmin Connect through the same import channel a Wahoo bike computer uses. Training Load behaves normally. Body Battery behaves normally. Readiness behaves normally. The activity card looks structurally identical to a native Garmin activity, except the rep counts, weights, and rest intervals are the numbers you actually did.

No silent cap. No mid-session cutoff. No 6-minute Connect cleanup ritual after every workout.

Rack is on the Connect IQ store. The full technical writeup of the FIT activity path is at /garmin-activities.

If you don’t want to install another app

Three things help, in order of cost:

1. End your strength activity manually at the 40-minute mark, save it, and start a new one. This prevents the silent cap from hitting at all, at the price of two activities per workout. If your training session is consistently 60+ minutes, set a recurring 40-minute timer on your watch as a reminder.
2. Pre-program your routine in Connect before the session.If you create a guided strength workout in Garmin Connect with the exercises and sets pre-defined, the watch follows the script and the buffer is allocated more efficiently. It doesn’t move the cap, but it pushes the failure mode further out for many users.
3. Photograph or write down your session before you start cleaning up in Connect. Once you start editing, you’re working from memory, and memory degrades fast. A 30-second phone note or a photo of your training notebook before you tap edit prevents the data drift that compounds over weeks.

Garmin’s native mode wasn’t built for the way you lift. Whatever you choose, the first step is knowing the cap exists.

If you’ve hit this same wall and want to compare notes, send me a message. I’m the dev. I read everything.