Minor Update: 2022
I define sports watches and wrist worn instruments which collect and display information that grants insight about health, fitness, and/or physical activities. My experience is that in most cases Garmin make the category leading watches. There are also “smart watches” which can be used as sport watches, but they focused on integration with smart phones, and are typically sub-standard for serious use with sports.
I would recommend checking out Ray Maker’s Buyer’s Guide if you are looking to purchase a sports watch. Ray publishes amazingly in-depth reviews. I have found Ray’s reviews are spot on for all the gear I have used and he has experience with many more products that me and tracks the industry much more closely that I do. The Quantified Scientist Youtube channel does reviews from a health accuracy perspective,
I have been impressed with the accuracy of Garmin metrics. I have compared it’s numbers (like calories burned) to the same data collected while I was at a performance measurement lab… the results were within 2% which is much better than the 20% or worse I saw from other systems.
I generally don’t recommend Fitbit unless people want basic activity tracking and have friends already in the Fitbit eco-systems. I started with Fitbit, but found them inaccurate except for basic step counting. Polar was a leader years ago, but gave up their lead. Suunto tends to lag Garmin in overall features, but can be good for endurance sports / activities. Apple iWatch is more featureful, but the battery life is too short for my taste, lack buttons which are important when your fingers are sweaty and you don’t want yo be distracted having to look at the screen. I don’t find it’s sports metrics are as good as Garmin… thought they have the potential to be as good or better.
As mentioned in my Gear post, I love my Garmin 955: a do everything watch which is light enough to wear everyday. It has decent integration with phones and provides every fitness and activity tracking feature you could want including SpO2. Fenix is a more expensive, metal case (more durable but all heavier) variant, which might have additional features such as downloadable maps.
Garmin 255 Watch: Superior to to the older 935 in every way: more advanced features, cheaper, lighter. It has most of the features of the 955. Ironically has a better feature set than some of the current Fenix models.
Garmin Vivoactive3 are cheaper, smaller, and I think more attractive. I would recommend this watch to anyone who doesn’t want to track multi stage events such as triathlons, are willing do without some of the more advanced fitness metrics, and don’t need route following navigation. You can download IQ apps that supports navigation, but it’s not integrated into the core of the watch. The Vivoactive4 and Venu are a step up, but I don’t think worth the extra cost.
Apple iWatch is now the most popular smart watch. It has great integration between the iPhone and the the iWatch, but the combination of it’s poor battery life (2 days best case, much less running GPS), touchscreen interface that doesn’t respond to sweaty fingers, and the so/so accuracy recording high excursion exercise stopped me from using an iWatch 1 I won in a raffle. Later models have better accuracy, and the Ultra model has a larger battery and added a button but still no support for power meters. For many people the iWatch is a great option.
Garmin Instinct is a watch designed for people who are more interested in trips into the back country than doing a triathlon. It looks like a Casio G-Watch. Has most of map/routing features of the Fenix 5 but lacks many of the more advanced sports metrics and no smart phone integration.
Suunto Ambit3 Peak was released in 2014 but is still champ when it comes to battery life with 1 min sampling of GPS: 200 hours run time, and almost a month run time with GPS turned off. Nice long-term review for hikers.
COROS Pace 2 is a lowest cost triathlon watch. Lots of good features in the watch itself including running power, but the app and external integrations are still weak.
Amazfit Bip (and other models) amazing prices. Decent phone integration / notifications, warns you when you loose connection with your phone (why doesn’t the iWatch do this yet?!!), always on display, great battery life: 4 days if using all the feature and some runs using GPS to >30 days if you don’t use GPS and display updates 1/minute. Big downside is the heart rate sensor is extremely poor, often off by +/-25% making it completely useless. There are some open source downloads which provide additional features.