Why I Use Both Garmin and WHOOP (And What Each One Is Actually For)
The Setup People Always Ask About
Every time I post a workout breakdown or a recovery analysis, someone asks: why do you wear both a Garmin and a WHOOP? Isn't that redundant? Don't they track the same things?
No. They don't. And understanding why is more important than the devices themselves.
Here's the framework I've settled on after wearing both simultaneously for over a year:
**Garmin = what you DID.**
**WHOOP = how you RECOVERED.**
Those are different questions. They require different hardware. Conflating them leads to making training decisions off the wrong data.
What the Garmin Is Actually Tracking
I have the Garmin Forerunner 265S. I chose the S specifically because I knew I'd want to sleep with it on to enable the daily suggested workout feature, which requires overnight wear. Smaller form factor, lighter, less wrist fatigue. I came from a Fenix (the bigger one) and I don't miss the weight.
What I actually use the Garmin for:
**GPS-locked activity data.** Over the past year — February 2025 through February 2026 — I've logged **111 runs and 265.1 miles** through Garmin. That dataset is clean, timestamped, GPS-verified for outdoor runs and cadence-verified for treadmill sessions. I know exactly what I've done because Garmin writes it down precisely.
My running started at a 1.02-mile treadmill session in February 2025. My longest run to date is 5.00 miles — a tempo run on June 30, 2025. My monthly peak volume was June 2025 at 76.8 miles across 24 runs. I'm currently in a race prep block (there's a local 4-mile race coming) and running 15+ sessions per month again.
None of that data comes from WHOOP. WHOOP doesn't do GPS. It doesn't log route data. It doesn't measure pace or cadence with the specificity Garmin does. When I want to know whether my 3.86-mile treadmill run averaged 14:00/mile at 130 HR — I'm reading the Garmin log.
**Workout-by-workout heart rate structure.** The Garmin gives me time in HR zones for every session. That March 15, 2025 outdoor run — which was the Lucky Charm race — maxed at 192 bpm with significant time in zones 4 and 5. That's race-effort data. A recovery run on February 11 averaged 117 bpm and stayed almost entirely in zone 1. The zone breakdown is how I verify that easy days are actually easy.
**Activity tracking for the AI system.** My OpenClaw fitness dashboard pulls Garmin data as one of six connectors. The Garmin history gives the morning report context on running volume, training load accumulation, and how that interacts with the WHOOP and Speediance data.
What the WHOOP Is Actually Tracking
WHOOP 5.0, worn on my wrist — and also in a bicep band or underwear when I'm rolling at BJJ, because a chest strap during jiu-jitsu is a miserable experience. The wrist option works fine for BJJ, though the bicep band gives better accuracy.
WHOOP doesn't care about GPS. It's not trying to log your run splits. What it does:
**HRV and overnight physiology.** The core WHOOP measurement is overnight HRV, resting heart rate, and respiratory rate. These are the inputs to the recovery score. HRV in particular — the variation between heartbeats — is the most sensitive indicator of autonomic nervous system state I've found. When it drops, something happened: too little sleep, too much training stress, alcohol, sickness, whatever.
**Recovery scoring with context.** The recovery percentage synthesizes the overnight data into a single actionable number. When I woke up on February 11 at 18% recovery with an HRV of 18.7ms, that number came from WHOOP tracking my body's physiological state through the night. Garmin was also on my wrist that night — but Garmin Connect still says "calibrating" on its readiness metrics. For right now, WHOOP is doing the heavy lifting on recovery intelligence.
**Strain from activities that don't have GPS.** This is actually where things get interesting. Until recently, my Speediance workouts weren't being counted toward my WHOOP daily strain at all. I was manually logging them, and they counted for almost nothing. Then Speediance started writing calorie data to Apple Health, and WHOOP picked it up and began modifying the strain score accordingly. My lifting sessions went from contributing near-zero strain to contributing 10+ strain points. My daily totals are now accurate in a way they weren't before.
Where They Disagree — And What I Do
They don't always agree on sleep. My 8Sleep Pod is a third data source, and on some nights all three tell a different story. The Garmin might log 7 hours, the WHOOP logs 5.5, the 8Sleep scores it a 74.
When WHOOP and 8Sleep diverge, I look at the HRV number specifically. HRV doesn't lie in the same way duration estimates can. Duration numbers depend on how each device defines "sleep" versus "restfulness" — and that varies between platforms. HRV is a physiological signal that doesn't have the same definitional ambiguity. If my HRV is low, I'm not recovered, regardless of how many hours the Garmin thinks I slept.
When Garmin and WHOOP disagree on effort — Garmin shows a high-intensity workout but WHOOP's strain is low — it's almost always because WHOOP missed some of the activity (Speediance doesn't write to Apple Health fully, or the BJJ session data wasn't captured properly). That's a data pipeline issue, not a sensor issue. I fix it by making sure the sync pathways are working.
The WHOOP 5 Question
People ask me constantly about upgrading to WHOOP 5. My take: the hardware is not actually smaller in any way that matters. They made it narrower and thinner in the band dimension — the two dimensions that don't affect comfort — while making it thicker off the wrist, which is the only dimension that matters. None of the WHOOP 4 bands fit. You need a spacer in the underwear accessory to make the sizing work. It feels like an intentional incompatibility move.
My WHOOP 5.0 works. The data is solid. I'm not upgrading until there's a meaningful sensor improvement.
The Framework in Practice
The decision tree is simple:
- **Checking run pace, distance, HR zones by session?** → Garmin
- **Deciding how hard to train today?** → WHOOP recovery score, confirmed by 8Sleep
- **Evaluating week-over-week training load trend?** → Both, through the AI dashboard
- **Understanding why I feel bad today?** → WHOOP HRV trend over the past 7 days
- **Logging a race or structured run?** → Garmin is the source of truth
These tools are not competitors. They're measuring different things on different time horizons. Using both — properly — gives you a more complete picture than either one alone. The key is knowing which question each device is actually qualified to answer.