What It Is: A mid-size GPS watch with a built-in heart rate monitor and Bluetooth connectivity.
Why We Like It: Epson's Runsense makes an ideal training partner for serious runners who don't need multisport or rugged backcountry watches. The standout feature of the SF-810, the top of Epson's four-watch Runsense line, is the optical heart rate monitor. It’s located on the back of the watch body, which eliminates the need for a chest strap. We found it consistent and accurate through recovery runs where we wanted to ensure we weren't pushing the pace. The same goes for tempo runs where we aimed to ride the edge of our anaerobic threshold.
After a workout, the watch connects to your Android or iOS device via Epson's Run Connect app. This sends your training data on to Epson's own Runsense online platform, and automatically updates any platforms you've linked to Runsense, like Strava, RunKeeper, and MapMyFitness.
Watch settings are also controlled and modified through your paired device. This makes setting the watch's numerous display options significantly easier. We set ours to feature screens with pace, lap time, and time of day, each with the heart rate displayed above, and total distance below. Our favorite feature of the Run Connect app, however, is the option to download and transfer satellite location data to the watch. Instead of waiting minutes for your GPS watch to get a signal before you can run, this lets you start tracking your workout in seconds.
Other features include a stride sensor that measures both cadence and stride length (this also records distance if you lose your GPS signal), a 20-hour battery with the heart rate monitor and GPS running, programmable intervals, vibration alerts, and the usual distance, altitude, and grade GPS measures.
The more affordable SF-510 ($250) and SF-710 ($270) models offer most of the same functions, but without the optical heart rate monitor — both can read a heart-rate chest strap. The SF-510 and SF-710 also provide a 30-hour battery life. The SF-110 ($170) provides basic GPS tracking and 10 hours of battery, which is still long enough to cover a week of miles for most runners.
Nitpick: When our workouts appeared on Strava, any distance (but not time) we covered while the watch was stopped — like while walking to a bathroom — was added to the total milage. Though this usually just added a tenth or two of a mile, it sped up the run's pace and any long detours skewed the workout data. Epson says it's aware of the problem and working to fix it.