The Polar H7 is a heart rate sensor that measures your heart rate and wirelessly sends real-time information to your phone. The device costs $79.95, and can be used with some of the Polar products, such as the Polar Loop fitness tracker, to add heart rate to the measures the tracker provides, such as number of steps, distance and level of activity.
The H7 can also be used alone with a mobile training app called Polar Beat (available for iOS and Android), which lets you use your phone to do the tracking. I used the H7 and the Polar Beat for about a week — here's how it performed. [Video: How Fitness Trackers Monitor Your Heart Rate]
The Polar H7 consists of a sensor and transmitter on an adjustable strap that goes around your chest. For measuring heart rate, chest straps are generally considered to be more accurate than wrist-worn devices such as watches, but comfort is also a factor. I am more used to wearing a wristband or a watch, so wearing something tight around my chest when exercising felt unnatural. But I got used to the feeling after a couple of days.
The H7 works with a watch battery and doesn't need to be regularly recharged through cables.
User friendliness: ★★★★☆
The Polar Beat app has a simple, straightforward design and is very easy to use. Depending on the type of workout and goals you choose, there are coaching alerts that will ask you to warm up, or speed up. These voice alerts are helpful if you're not wearing one of the fitness trackers, because unlike a wristwatch, it's not easy to look at your phone during a workout to see your heart rate. [Best Fitness Tracker Bands]
Value of information: ★★★★☆
Considering the fact that the Polar H7 is a heart rate sensor and not an activity tracker, it did a good job of providing more than just the heart rate by pairing with the app on the phone.
For example, during your workout, the app displays your heart rate in real time, as measured by the sensor on the chest, and also the distance you've traveled as measured by the phone's GPS, and your speed. Based on your speed and heart rate, the app estimates how many calories you have burned and how much you have improved your fitness.
When reviewing your workout summary, the app displays colorful charts showing where your heart rate fell within several zones, based on the percentage of maximum heart rate. For example, the lowest zone is your expected heart rate during light exercises such as walking, and the highest zone is the maximum heart rate you achieve during athletic training. The charts show the amount of time you spent in each zone.
There are many variables to measure during exercise — distance, speed and calories — but I still found it exciting to know my heart rate. Pairing up a simple device such as the H7 with my phone made running more enjoyable because it provided a direct sense of what running is doing to my body and my heart. In a way, it made the effects of exercising more tangible to me.
Conclusion: 15 out of 20 stars
Adding the Polar H7 to Polar fitness trackers provides valuable information about heart rate and intensity of workout. But the simple, easy-to-use mobile app made the Polar H7 stands on its own as a basic activity tracker or a training buddy.
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Email Bahar Gholipour. Follow us @LiveScience, Facebook & Google+. Original article on Live Science.