Strapless Heart Rate Monitor Watch (Wrist-Based)

Facebooktwittergoogle_plusmailby feather

The world of fitness tracker has moved from the common accelerometer for step counter function to on-board heart rate sensor to measure calories burned more accurately.

Some of the strapless heart rate monitor watches that available in the market are as follows.

Mio ALPHA 2 Heart Rate Watch

Mio ALPHA 2 Heart Rate Watch Activity TrackerInstead of focusing on all-day fitness activity tracking, the Mio ALPHA 2 Heart Rate Watch emphasizes on running, bicycling, and other high-intensity activities. One thing that makes it different from many (if not most) activity trackers is the lack of sleep monitoring function.

However, it makes up that missing feature by providing various functionalities for multiple intense workouts. It syncs with both Android and iOS devices via Bluetooth Smart. A number of running and bicycling apps are compatible with the ALPHA 2 including but not limited to Strava, Runtastic, MapMyRun, Cyclemeter, MapMyRide, Wahoo Fitness, and miCoach. Mio also provides free PAI app to help you translate heart rate into understandable metrics.

The ALPHA 2 is fully water resistant to 30 meters (3 ATM or withstand water pressure equivalent to 100 feet deep), making it ideal for day-to-day activity tracking. It records steps, heart rate, pace, distance, speed, calories, and goal progress. Heart rate zones are user customizable.

Additional features include countdown, chronograph, repeat timer, and audio/visual alert when you reach new heart rate zone. ALPHA 2’s display is a mineral glass LCD that holds up well under bright light. The watch is powered by rechargeable lithium polymer, providing up to 24 hours of workout mode or 3 months of timekeeping mode.

Polar A360 Fitness Tracker

Polar A360Having been in the industry since late 1970’s, Polar has finally joined the crowd to include on-board heart rate sensor in fitness activity tracker, the Polar A360 Fitness Tracker with touchscreen display. Typical fitness tracker features are all present; it measures steps taken, distance travelled, calories burned, active time, and sleep pattern.

It also gives inactivity alerts after 55 minutes of being physically inactive. Another interesting feature is that Polar offers various sport profiles based on which the device will deliver measured metrics. Battery life is good enough at up to 12 days of all-day activity tracking or 7 days of training mode without smart notification.

Polar even includes its Smart Coaching feature in the A360. It is comprised of many different functions based on heart rate calculation. One of them is activity guide with which the fitness tracker delivers exact practical guidance; depending on your fitness level, the watch may tell you to jog or walk for certain period of time to meet your goal.

Calories burned computation is not solely based on heart rate only, but also individual profile including age, height, weight, gender, and activity intensity. When used with Polar App or Polar Flow, you get detailed reports and analysis of fitness metrics gathered by the device.

Polar A360 can act as simple smartwatch as well by displaying notifications received on your smartphones. Notifications may include incoming calls, text messages, social media, calendar alerts, etc.

Garmin vivosmart HR

Garmin vivosmart HR Activity TrackerMore advanced approach by Garmin was demonstrated by the company’s Garmin vivosmart HR. It is still an activity tracker that has all basic functions to measure steps, calories, sleep, and distance. The small touchscreen display delivers all measured metrics and smartphone notifications as well.

There is no additional training mode in vivosmart HR, but Garmin inserted a barometric altimeter sensor to calculate the number of stairs you climb. Smart notification feature is compatible with major smartphone operating systems including Android, iOS, and Windows 10 Phone. The screen is small, but it can display notifications and contents.

Similar to the aforementioned devices, vivosmart HR is equipped with an on-board heart rate monitor. Since it holds a 5 ATM water rating, the watch is ideal for all-day fitness tracking. There is move bar, which develops after a period of inactivity for an hour; you can reset this move bar to zero by walking for a couple of minutes.

Garmin improves smartphone connectivity feature by allowing the vivosmart HR to control your phone’s music player and ring the phone in case you forget where you put it. The watch can even act as remote control for VIRB action camera. There is also Intensity Minutes function which monitors activity time to meet the widely accepted standard of 150 minutes per week.

Garmin Forerunner 225

Garmin Forerunner 225It is another sport watch by Garmin equipped with wrist-based heart rate monitor, but the Garmin Forerunner 225 is also loaded with features for runners. It has all day-to-day activity tracking functions to measure steps, calories, sleep, and heart rate.

Automatic goal based on your previous achievement and inactivity bar are available as well. Compared to vivosmart HR, the Forerunner 225 lacks of smart notification and VIRB compatibility. The heart rate sensor equipped on this watch is developed by Mio.

Garmin Forerunner 225 focuses more on running rather than activity tracking. A number of running features are available for examples Auto Lap, Custom Goal-oriented workouts, Interval Training, Auto Pause, Auto Scroll of data pages, and Pace Alerts.

Let us not forget that this sport watch also has GPS. Its activity tracking function uses both heart rate sensor and accelerometer; the latter replaces the needs for additional footpod to measure distance during indoor workout on treadmill. Battery life is quite good at 10 hours in training mode (with GPS on) or 4 weeks in watch mode. It holds 5 ATM water rating and is shock resistant.

Garmin Forerunner 235

Garmin Forerunner 235Garmin has done a major improvement project for the Forerunner 225 by adding a variety of new features to introduce the Garmin Forerunner 235. In short, Forerunner 235 has all the features you can find in the Forerunner 225, yet the predecessor takes the running function to a new level. Three new running metrics are provided including VO2 Max, Recovery Advisor and Race Predictor.

On the hardware department, Forerunner 235 is superior for it has GPS and GLONASS as well as compatibility with smartphones to display notification and control music player. One of the biggest additions is Connect IQ, the company’s own app store, which allows user to install more apps on Forerunner 235.

Some apps add functionality, while others are for customization. Battery life suffers a little when used in timekeeping mode because it has at least 4 active functions: watch, heart rate sensor, activity tracking, and smart notification. As a result, Garmin Forerunner 235 only has about 9 days of battery life. For training, the watch can stay on for 11 hours.


Before the introduction of on-board or wrist-based heart rate monitor, you have to rely on 3-axis accelerometer to gather data and convert them to calorie computation in which process much guesswork is involved.

More accurate computation is possible with help from heart rate strap, which some might find it uncomfortable. Now that new models of fitness trackers have heart rate sensor mounted on its back (also commonly referred to as heart rate monitor watch), users are now able to measure activities and amount of calories they burn based on heart rate beats per minutes (bpm) for 24 hours every day without any additional strap.