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Best GPS Watches for Triathlon — Why I Switched From Apple Watch to Garmin (And What I Would Buy Next)

I learned the hard way that not every GPS watch is built for endurance sports. My first multisport watch was an Apple Watch Series 1. It tracked my runs, looked great, and did everything a smartwatch should do — right up until it died halfway through a half marathon. Dead battery, no data, no finish line split. That was the last time I relied on an Apple Watch for a race.

I switched to the Garmin Fenix 5 and have been wearing it for over five years. It has been on my wrist through sprint triathlons, half iron distance races including Ironman 70.3 Dallas, open water swims, and thousands of miles of training. It is the piece of gear I trust more than almost anything else in my kit.

In this post I am going to walk you through what I have used, what I would recommend at different price points, and what I am personally planning to buy next — the Garmin Fenix 7 Solar — as soon as my bonus hits.

Quick Picks at a Glance

Best overall for triathletes: Garmin Fenix 7 Solar

Best mid-range: Garmin Forerunner 965

Best budget entry: Garmin Forerunner 255

Best Apple ecosystem option: Apple Watch Ultra 2

What I have worn for 5+ years: Garmin Fenix 5

Why Apple Watch Does Not Work for Triathlon

The Apple Watch Series 1 died on me at mile 7 of a half marathon. That was enough for me.

Battery life is the dealbreaker. The original Apple Watch was rated for about 18 hours of general use — which sounds fine until you realize that GPS tracking in workout mode drains it dramatically faster. I did not make it through a half marathon. For a triathlon where you might be racing for 5-17 hours depending on distance, that is simply not workable.

Apple has improved significantly with the Apple Watch Ultra 2, which now offers legitimate multi-sport tracking and much better battery life. If you are deeply embedded in the Apple ecosystem and want to stay there, the Ultra 2 is the first Apple Watch I would actually consider for triathlon. But it comes at a premium price and still does not match Garmin for triathlon-specific features.

For most triathletes, Garmin is the answer. Here is why.

What I Have Worn for close to 10 Years — Garmin Fenix 5

I have been racing and training with the Garmin Fenix 5 for close to ten years. Here is my honest take.

The Fenix 5 was built for endurance athletes and it shows. Battery life in GPS mode runs 24 hours — enough for a full Ironman with room to spare. The multisport mode lets you move seamlessly between swim, bike, and run with a single button press, which is exactly what you need in a triathlon transition.

After ten years of daily wear, pool swims, open water swims, long rides, and races, it still works perfectly. The screen has scratches. The band has been replaced once. The watch itself is bulletproof.

What it lacks compared to newer models: No solar charging, older maps, no multiband GPS. It is a 2017 watch and it shows in a few areas. But for a triathlete who just needs reliable multisport tracking and battery life that lasts through any race, it still does the job.

The Fenix 5 is discontinued but you can still find it used or refurbished. If budget is a concern it is worth considering — just know you are buying older technology. Facebook marketplace is a great place to look for these.

What I Am Buying Next — Garmin Fenix 7 Solar

Price range: $599-$899 depending on size and edition

I am saving for the Fenix 7 Solar. This is the watch I would buy today if I were starting fresh.

The solar charging is the headline feature and it is genuinely meaningful for endurance athletes. In training mode with solar assist, battery life extends significantly beyond the standard GPS mode rating — on a sunny Texas ride you are adding meaningful charge just by being outside. For Ironman-distance racing and big training weeks, that matters.

The Fenix 7 also adds multiband GPS for significantly improved accuracy, a touchscreen alongside the traditional buttons, and Garmin’s latest health monitoring features including HRV status and improved sleep tracking. It is a meaningful upgrade from the Fenix 5 in almost every area.

Who it is best for: Serious triathletes who want the best multisport watch on the market and are willing to pay for it. If you are training for a half or full Ironman, this is the one to get.

Search “Garmin Fenix 7 Solar” on Amazon for current pricing — prices vary by size (47mm vs 51mm) and edition.

Best Mid-Range Option — Garmin Forerunner 965

Price range: $499-$599

If the Fenix 7 price is hard to swallow, the Forerunner 965 gives you most of the same triathlon functionality at a lower price point. It has full multisport mode, AMOLED display, multiband GPS, and excellent battery life. The main difference from the Fenix line is the build — the Forerunner is lighter and less rugged, which some athletes prefer for racing.

Who it is best for: Triathletes who want premium GPS features without the Fenix price tag. Excellent choice for sprint through half iron distance racing.

Search “Garmin Forerunner 965” on Amazon for current pricing.

Best Budget Entry — Garmin Forerunner 255

Price range: $249-$349

For athletes just getting into triathlon who do not want to spend $600 on a watch, the Forerunner 255 is a legitimate starting point. It has multisport mode, solid GPS accuracy, and battery life that will handle any sprint or Olympic distance race comfortably. It lacks some of the advanced training metrics of the higher-end models but gives you everything you need to race and train effectively.

Who it is best for: First-time triathletes or athletes on a budget who still want a reliable Garmin multisport watch.

Search “Garmin Forerunner 255” on Amazon for current pricing.

What to Look For in a Triathlon GPS Watch

Multisport mode is non-negotiable. You need a watch that can track swim, bike, and run as separate activities and transition between them quickly. Not all GPS watches have this.

Battery life matters more than you think. For sprint distance you need 2-3 hours. For half iron you need 5-8 hours. For full Ironman you need 12-17 hours. Check the GPS mode battery rating before you buy.

Open water swim tracking. Make sure your watch supports open water swimming, not just pool swimming. Most Garmin multisport watches do but always verify.

Bike computer compatibility. If you use a separate bike computer like I do, make sure your watch can connect to your power meter and heart rate monitor simultaneously.

Bottom Line

If you are serious about triathlon, get a Garmin. The Apple Watch taught me that lesson at mile 7 of a half marathon and I have not looked back in five years. My Fenix 5 has been one of the best gear investments I have made and the Fenix 7 Solar is next on my list.

Budget pick: Forerunner 255. Mid-range: Forerunner 965. Best in class: Fenix 7 Solar. Any of the three will serve you well on race day.

Questions about which watch is right for your distance or budget? Drop a comment below.

— Andrew | My Life With AE | Competitive triathlete, 10+ years racing, Ironman Jacksonville 2027