Gear Review: A Strapless Heart Rate Monitor for Every Type of Athlete

All the benefits of heart rate training without an annoying chest strap

Heart rate monitors are nothing new to the fitness scene. They've been a valuable tool for everyday athletes and fitness fanatics since Polar released the “Micro Heart Pulser” in 1977.

They're a great training tool and can offer exercisers and athletes worthwhile details about their fitness levels and athletic performance. However, the majority of everyday exercisers have one big complaint about most heart rate monitors on the market right now: the “annoying chest strap.”

Most models work with a watch and a strap that connect via Bluetooth technology. The strap is worn around your chest in order to determine your heart rate. However, the Mio Alpha strapless heart rate monitor works without Bluetooth technology. Just as its name suggests, it requires no chest strap, only a watch.

LED and “electro-optical cell” technology on the back of the watch read blood flow volume to detect your heart rate. For what it was made to do, the Alpha is a great tool. However, unlike many monitors that do require a strap, the Alpha functions solely to read your heart rate, and while exercising, to alert you when you’re not within your preset zone. If you're willing to forgo fancier features like GPS tracking and post-workout calorie burn reports in order to avoid wearing a chest strap, you'll appreciate the Alpha and its simplicity. (Although if those features are a must for you, the Alpha does have the capability to connect to apps like MapMyRun and Strava via Bluetooth.)

Like almost any other gadget, before working out with the Alpha I had to perform an initial setup. The process of turning it on for the first time and entering my information like age, height, and weight was simple. The directions in the quick start guide are easy to follow. The first time I commanded it to detect my heart rate it displayed the data within about 30 seconds. The reading it gave me was accurate compared to my previous resting heart rate readings with other heart rate monitors. (Mio claims 99% accuracy even at speeds of up to 14.4 MPH.)

The directions in the quick start guide are clear and simple. Following the step-by-step instructions made it easy to pick a heart rate range and initiate the “Exercise Mode.” However, with only four vaguely named buttons (toggle, set, HR, and timer), getting the watch to work without the guide would be quite a challenge. In fact, because it’s not very intuitive, even after having used the watch two or three times I needed to re-consult the guide to get it started up.

The concept is simple, though. Before beginning your workout, you set a high and low heart rate. This tells the watch what heart rate range you’re aiming for during your workout. When you’re ready to go, pressing and holding the “timer” button activates the “HR Zone Alert.” When you reach a heart rate within your desired zone, the light on the front of the watch flashes green. If you’re outside of the zone at any point during your workout, the light flashes red and the watch beeps.

The “HR Zone Alert” is the Alpha’s most significant feature and I found it beneficial because it meant that I didn’t need to constantly look down at my wrist to find out whether or not I was working at the correct intensity level. When you’re workout is over, the watch reviews the amount of time spent exercising, your average heart rate, and time spent “in the zone.” After my first workout with the watch I was expecting a calorie burn report too, but even though caloric expenditure is directly related to heart rate, the Alpha does not calculate it.

There's no doubt that the Alpha is a valuable tool for all types of exercisers. From a triathlete aiming to PR at their next race to the fitness first-timer ready to commit to a regimented exercise routine, heart rate training is an excellent method for tracking fitness progress, and the Alpha is a simple and effective way to do so.


  • No frills, simple concept
  • Audio alerts allow you to focus on exercising instead of constantly having to look at the watch
  • Comfortable
  • Can connect to iPhone apps if more features like calorie burn or GPS tracking are desired


  • Because the optical sensor that reads blood flow volume must be in direct contact with your skin, the watch is not ideal for outdoor winter sports (like running) that require long-sleeve layers
  • The buttons are not intuitive and also somewhat difficult to click