A rugged, capable fitness watch that does everything you need — and nothing more — the Instinct 3 Solar’s simplicity might just be its greatest strength.

Key Specifications

Display Size: 45mm (0.9″) / 50mm (1.1″)
Display Type: Memory in Pixel (MIP)
Satellite/GPS Tech: Multi-Band with SatIQ
Weight: 53g (45mm)

Last year, if you’d asked what my VO2 Max was, how I’d slept, or what my predicted marathon time was looking like, I could have told you without checking. Not just the figure — the trend. Whether it was up or down on yesterday, on last week, on last month.

After several months with the Garmin Instinct 3 Solar, my answer would be: “let me check.”

I’m not sure exactly when it happened, but at some point the metrics stopped being a means to an end and became the thing itself. And I don’t think that’s entirely my (our) fault. AMOLED displays — bright, vivid, demanding attention — have a lot to answer for. Put a glowing screen on your wrist and your brain will find reasons to look at it. The data is always there, always fresh, always one scroll away from something else to optimise.

The Instinct 3 Solar has all the same metrics. The data is identical. But the MIP display doesn’t invite you in — it sits there, telling the time, waiting to be useful rather than asking to be admired. There’s something quietly countercultural about that in 2025. We live in an attention economy where every screen — your phone, your laptop, your TV — is engineered to keep you looking, and fitness watches haven’t been immune to that. AMOLED displays are beautiful, and I say that as someone who owns and enjoys them. But beauty has a cost, and part of that cost is the compulsive checking, the mindless scrolling through widgets, the creeping sense that the data has become the point, rather than the health it’s supposed to serve. The MIP display breaks that loop — not because it gives you less, but because it never made looking at it feel like a reward in the first place. In a world that profits from your attention, a watch that doesn’t want it might be the healthiest thing you can put on your wrist.

Why the Garmin Instinct 3 Solar?

For the bulk of Garmin’s existence, Memory-in-Pixel (MIP) has been the display technology of choice. While MIP might not offer the same vibrancy of colours or clarity of AMOLED, it tends to provide the wearer with far more functional benefits — battery life and readability in daylight chief amongst them.

Garmin’s foray into AMOLED began with the Venu, a smart-oriented device aimed squarely at Apple Watch territory. It continued with the resurrection of the Epix line, with Gen 2 becoming the AMOLED version of the Fenix — targeted at “more serious” endurance athletes who also valued modernity. It must have worked, because that segmentation was scrapped with the release of the Fenix 8, which became AMOLED by default. MIP survived only in the solar edition.

Garmin isn’t the only brand moving in this direction. Last year, Suunto scrapped MIP in favour of LTPO AMOLED in their flagship — the Vertical 2. The options available to MIP devotees shrink with every new release, and I fear it won’t be long until it’s a mostly forgotten technology.

On the one hand, it’s not surprising. Advances in AMOLED and LTPO technology have reduced what was previously a significant power penalty. The Suunto Vertical 2, for example, boasts broadly comparable battery life specs to its MIP-displayed predecessor. But the appeal of MIP isn’t always only about battery life. Many prefer its performance over AMOLED in daylight. And, as I’ve come to appreciate through testing the Instinct 3 Solar, some people just prefer their fitness watch to remain a quietly competent tool — something that sits in the background, not demanding attention, ready to go when you are.

Design & Build

The Instinct line has always been the retro, G-Shock-inspired watch in Garmin’s lineup. With the updated 3, there are no dramatic changes in design, and that’s a huge positive. The Solar edition I received, black with rust accents, is a real head-turner.

I’ve put the Instinct 3 Solar through the kind of treatment that would leave most watches looking their age — the usual knocks and scrapes that come with daily wear, runs through undergrowth, and the general carelessness that sets in once a watch stops feeling new. Several months in, you’d be hard-pressed to find a mark on it. It’s holding up better than any fitness watch I’ve previously owned, and I’ve owned a few.

That’s not entirely surprising once you understand what’s underneath the design. The metal-reinforced bezel does the job it’s there to do, absorbing impacts that would chip or crack a lesser frame. The whole watch is built to MIL-STD-810 standards — military-grade testing covering thermal extremes, shock resistance, and water resistance to 100 metres.

There’s something to be said, too, for a design that doesn’t require you to be precious about it. Part of what makes the Instinct 3 Solar genuinely freeing to use is the absence of anxiety about damaging it. You put it on, you forget about it, and it keeps going. For a watch positioned as a rugged outdoors tool, that’s exactly the right relationship to have with it.

Screen & User Interface

The Instinct 3 Solar utilises a Memory-in-Pixel display. Not only does this not offer the vibrant colours of AMOLED — it doesn’t offer colour at all. The monochrome display retains the classic Instinct dual-window layout: a main screen area plus a smaller secondary window. I couldn’t tell you exactly why I like this setup, but I do. You can choose the metric displayed in each window, both during and outside of activities, and owing to its size relative to other on-screen elements, it’s easily visible at a glance.

There’s no touchscreen, either — something I’d normally consider a drawback, given how intuitive touch navigation has become. But on a watch without mapping capabilities, there’s nothing that actually benefits from it. Five-button navigation handles everything the Instinct 3 Solar needs to do, and handles it without fuss. In that sense, the absence of a touchscreen feels like the right call.

I’m sure some reviewers will call the Instinct 3 Solar “boring and outdated” in 2025, and I understand the argument. But I have to disagree. The combination of a monochrome MIP display and the absence of a touchscreen appeals to the part of me — quite a large part — that thinks society would genuinely benefit from going “backwards” in certain respects. There’s no denying the Instinct 3 Solar is simple. But, considering its capabilities, it’s far from boring or outdated.

Solar & Battery Performance

Garmin overhauled the solar charging layer for this generation — notably eliminating the reddish cast users noticed on older models. The solar element has also been moved away from the display area entirely, sitting only on the watch’s bezel and case. Counterintuitively, this smaller footprint actually collects more solar energy than before.

Having predominantly tested the Instinct 3 Solar over a UK winter, I was fairly convinced the word ‘Solar’ on the display was merely the model name. If it’s an in-depth analysis of solar performance you’re after, I’m happy to cede that ground to DC Rainmaker.

Nonetheless, in just the last week, those of us in the UK were treated to not just a rare sighting of the sun, but four consecutive days of cloudless skies. It gave me a brief but genuine insight into the Instinct 3’s solar charging — and I came away impressed. After roughly five hours in the sun at what Garmin tells me equates to 57,000 lux hours, the watch gained a not-insignificant few percent of additional battery.

If you’re a UK-based or otherwise sun-starved runner or hiker, you’ll need to temper your expectations. The advertised “unlimited battery life” isn’t something you’re going to experience. But with the standard Instinct 3 now switching over to AMOLED, the Solar is really your only option if a MIP-displayed, rugged, retro-style Instinct is what you’re after. The solar capability becomes a nice-to-have rather than the headline feature. At least in this country.

One useful thing to know: if you do run the battery down, a full charge from empty takes around two hours. You can also customise Battery Saver mode to switch off only the sensors you don’t need, which can meaningfully extend life without sacrificing everything.

When it comes to the Instinct 3 Solar’s regular battery-life (sans solar), I have a little more experience. Battery life specs can be notoriously easy to misread, so the figures you actually need are these:

• Smartwatch Mode: Up to 40 days (unlimited with solar)
• GPS Only: Up to 60 hours (260 hours with solar)
• All-Satellite Systems: Up to 40 hours (80 hours with solar)
• All-Satellite Systems + Multi-Band: Up to 34 hours (60 hours with solar)
• Max Battery GPS: Up to 150 hours (unlimited with solar)
• Expedition GPS: Up to 60 days (unlimited with solar)

(P.S Solar charging assumes all-day wear with 3 hours per day outside in 50,000 lux conditions)

As runners, the GPS categories are really all that matter. The simplest way to think about them: the longer the quoted battery life, the less accurate the tracking. I stick mine in the most accurate mode — all-satellite systems + multi-band — and forget about it. In real terms that translates to roughly two to three weeks between charges, based on around 50km of weekly run tracking, continuous HR monitoring, and sleep tracking. Charging once a fortnight is perfectly acceptable. It’s what I’ve come to expect from Garmin, and a big part of why I keep coming back to their devices.

GPS & Tracking

Let’s start with a notable negative — GPS lock-on. Compared with the Suunto Vertical 2, the Garmin is noticeably behind. In testing, the Instinct 3 Solar takes roughly twice as long to acquire a signal. What is harder to excuse is the watch’s occasional reluctance to lock on at all. On more than one occasion, the GPS progress bar simply stopped moving. The fix was, as it so often is with technology, to turn it off and back on again.

A quick look at online forums suggests this isn’t isolated. It’s frustrating, particularly given that getting out the door is often the hardest part of a run. I’d hope it’s a bug Garmin are actively working on.

When a signal is found, tracking is accurate and reliable. It’s worth flagging that the Instinct 3 also features SatIQ — a system that dynamically optimises GPS performance based on signal conditions, balancing accuracy and battery life automatically. In practice, that means you can largely set it and forget it without manually managing modes mid-activity.

Training & Everyday Health Metrics

The Instinct 3 Solar’s feature set punches well above its price point. On the training side, you get the full Garmin suite: VO2 Max, Training Status, Training Readiness, Training Load, recovery time, and the ability to follow structured workouts and multi-sport training plans directly from your wrist. Daily suggested workouts adapt based on your recent activity and recovery, meaning the watch doesn’t just track what you do — it has an opinion about what you should do next. For everyday health, continuous heart rate monitoring runs alongside HRV Status, Body Battery, Pulse Ox, stress tracking, hydration logging, and menstrual cycle tracking. Sleep Score, sleep stage breakdown, and the Morning Report round out what is, by any measure, a comprehensive health monitoring package. Whether you engage with all of it is entirely up to you — and as I’ve found with the Instinct 3 Solar, the beauty is that it never pressures you to.

Most of these features perform as you’d expect from a Garmin device — reliably and without fuss. A couple, however, are worth expanding on.

Heart Rate

Garmin went with the Elevate 4 sensor rather than the Elevate 5 found on devices like the Fenix 8. In day-to-day use it’s generally reliable. During running, wrist-based HR monitoring is inherently less consistent — not because of the sensor itself, but because of arm movement, sweat, temperature, and whether the watch is covered by a sleeve.

There’s an additional wrinkle with the Instinct 3 Solar specifically. The stock strap has thicker, harder plastic at the point where it connects to the case, which means the sensor doesn’t sit quite as flush against the skin as it might with a softer band. Ultimately, this will depend on your wrist size, but for running it may be worth switching to something like the Ultrafit Nylon strap. For hiking, it’s less likely to matter.

I don’t personally train by HR for this reason, but if you do, the gold standard remains a chest strap — the Garmin HRM Pro Plus being the obvious companion here.

Sleep Tracking

The Instinct 3 Solar tracks sleep automatically, breaking it down into light, deep and REM stages, and producing a Sleep Score each morning. It also tracks naps, an additional feature I first experienced with the Epix Gen 2. Since then, however (and the reason I’m addressing it), both sleep and nap tracking seem to have considerably improved. In testing, the times recorded for falling asleep and waking were consistently accurate. What’s also consistent is my inability to record a perfect 100 Sleep Score. My best attempt so far was an irritatingly close 96.

Comfort & Wearability

Despite its chunky, rugged appearance, the Instinct 3 Solar is lighter than it looks. At 53 grams for the 45mm version, it strikes a reasonable balance — substantial enough to feel like a proper watch, light enough that it doesn’t become a burden during long activities or overnight. The stock silicone band is durable, if a little stiff — and as noted in the Heart Rate section, it doesn’t sit quite flush enough for optimal sensor contact during running. Swapping to a softer aftermarket band is worth considering.

One question I’m asked about every fitness watch I’ve ever owned is “how do you sleep with that?” Truthfully, I don’t notice it. It doesn’t disrupt my sleep at all — though perhaps my sleep scores would disagree.

Additional Features

I said it in my review of the Suunto Vertical 2 and I’ll say it again: the flashlight is a genuinely brilliant — and now essential — feature. Mostly you’ll use it for finding things in the dark without waking anyone. But it’s bright enough to be legitimately useful on the trail (or road), and the Instinct 3 offers more safety modes than the Suunto should you ever need them.

The ABC sensors — altimeter, barometer, compass — are reliable and useful, particularly the barometric altimeter for elevation data during runs or hikes. The storm alert, which flags a significant drop in air pressure, is the kind of feature that earns its keep precisely once, when it actually matters.

What It Doesn’t Do

The Instinct 3 Solar doesn’t offer full mapping, and at this price point in 2025 that’s a genuine criticism worth making plainly. Competitors across a wide price range — including from Garmin’s own lineup — now include offline maps. For an outdoors-focused watch launching at this price, the absence is difficult to justify.

You can navigate routes via breadcrumb, and for straightforward trails it works fine. But for anything more complex — multiple paths heading in similar directions, less well-trodden terrain — it falls short. If detailed navigation is important to you, you need to look further up Garmin’s range.

The watch also lacks music storage, which won’t matter to some but is worth flagging for those expecting it. No Spotify, no offline playback.

Price & Value

The 45mm Instinct 3 Solar retails for £349, and whether that represents good value depends largely on the lens you’re looking through.

Within Garmin’s own ecosystem, it’s compelling. The Instinct 3 Solar carries the same sensors as my Epix Gen 2 and replicates almost everything that watch does — the only meaningful omissions being navigation and offline music playback. When the Epix Gen 2 launched in 2022, the base model cost £799.99. By that measure, £349 feels like a bargain.

The caveat is that the technology inside the Instinct 3 Solar is, by definition, a generation or two behind. That’s not unusual — flagship hardware always filters down to more affordable devices over time — but it does mean that with a little research, you can sometimes find a better deal than you might expect. The Epix Gen 2 Pro, for example, offers a meaningfully larger feature set and more recent sensors, and can currently be found for around £369. Whether that’s the smarter purchase depends on what you actually need from the watch — but it’s worth checking before you buy. One thing to verify regardless of which route you take: Garmin’s software support timeline for older devices, which varies and isn’t always clearly communicated.

In the wider market, the picture is slightly more complicated. There are plenty of fitness watches at this price point with comparable feature sets, but very few that share the Instinct’s rugged, retro aesthetic. The most direct competitor is the Coros Nomad at £319 — and crucially, it includes fully mapped navigation, something the Instinct 3 Solar conspicuously lacks. I haven’t tested the Nomad personally, so I’ll defer to DC Rainmaker for a detailed comparison, but its existence changes the conversation. Until recently, Garmin had something close to a monopoly on this particular niche — the athlete who wants modern training features wrapped in something that looks like it was built for a military expedition. The Nomad suggests that’s no longer the case, and Garmin would do well to take note.

Who It’s NOT For

The Instinct 3 Solar is a compelling watch, but it’s not for everyone — and it’s worth being honest about that before you part with £349.

If you’re a runner primarily looking for a streamlined training tool, Garmin’s Forerunner range is arguably the more natural fit. There’s very little difference under the hood, but the Instinct 3 is chunkier and less refined in profile than the Forerunners — a trade-off that makes sense if the rugged aesthetic is part of the appeal, less so if it isn’t.

Size is also worth considering. The Instinct 3 Solar starts at 45mm, which will be too large for some wrists. The Instinct E addresses that with a 40mm option, but removes enough features — including the metal bezel, multi-band GPS, and the flashlight — to make it a meaningfully different watch. If you’re set on the Instinct look but have smaller wrists, it’s worth trying both on before committing.

If offline maps are important to you — and for complex or unfamiliar terrain, they genuinely are — you’ll need to look further up Garmin’s range. The Fenix line and the Enduro 3 both offer full topographical mapping; the Instinct 3 Solar doesn’t, and no software update is going to change that.

If you’re coming from a modern AMOLED watch, the display will feel like a step down — at least initially. Whether it ends up being something you miss or something you barely think about is, as this review probably suggests, a more interesting question than it first appears.

Finally, if you live somewhere the sun rarely appears — and as a UK-based reviewer I say this with some authority — the Solar premium buys you relatively little in practice. That said, with the standard Instinct 3 now AMOLED by default, the Solar is one of only two MIP-display options left in the Instinct range. If a MIP display is what you’re actively looking for, your choice is essentially this or the more stripped-back Instinct E.

Gritty Verdict

I’ve tested a lot of fitness and smartwatches over the past few years — Garmin, Apple, Suunto, and plenty in between. Each has its pros, its perks, and its quirks. But more than any spec sheet or feature list, what I keep coming back to with the Instinct 3 Solar is its simplicity.

It’s capable — very capable — but it never gets in the way. Training plans, structured workouts, post-session analysis, Strava sync. Sleep Score, HRV, Body Battery, Pulse Ox, Training Readiness, VO2 Max. Aside from maps and InReach capabilities, there’s very little the Instinct 3 Solar can’t do. The difference is that it never makes you feel like you should be doing more with it.

In a world of constant AMOLED screens — phones, laptops, watches — the Instinct 3 Solar feels like a small act of defiance. It gives you the benefits of modern training technology without pulling you further into the dopamine doom-scroll. The data is there when you want it. It’s just not screaming at you.

It’s a reminder that embracing new technology and being consumed by it are two very different things. It takes everything useful and leaves the rest at the door.

Set it. Run. Save. Get on with your life.

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