The best heart rate monitor without a chest strap (November 2015 UPDATE)

Chest straps have been an unfortunate downside to heart rate monitors since the beginning of time. They have been the necessary evil needed for the device to gather your all-important heartbeat. The problem is, Chest-strap heart rate monitors suck. Sure, they work well enough, most of the time, but let’s face it, nobody likes wearing them. They’re clunky, they’re difficult to clean, they add bulk under your workout gear and they have a knack of losing connection for periods of your training. Enter the Mio Alpha, a wristwatch that accurately measures your heart rate. It is quite simply the best heart rate monitor without a chest strap on the market today in my opinion.

November 2015 update: We recently did a deep dive into the effectiveness of heart rate monitors, fitness bands and smart watches. We still believe that the Mia Alpha remains a great strapless watch, but we do now have reservations about the quality of the readings and the accuracy of the data which these devices collect. Check out our post here looking at the science behind heart rate monitoring an whether a strapless HRM can ever be as accurate as a strapped up version.

What Is It?

It’s a watch that measures your heart rate but which does not require a chest strap

Who’s It For?

Runners seem to gravitate towards heart rate monitors the most, but this type of device really is a must have for anybody who takes their workouts seriously. Cyclists, general gym goers and even dog walkers can all monitor their fitness and the improvements they’re making with a good heart rate monitor. You’re never lively to strap up in order to go for a walk, but slipping a sports watch on is no major drama.


Design wise, this watch is nothing special and if anything, is more of a throwback to heart rate monitors from a few years ago. Mio have avoided the seemingly overbearing temptation to make the watch gaudy and bright, but have instead executed a design which is a plasticy-looking digital watch with a rather thick wristband. The Mio Alpha lacks the sophistication of devices like the TomTom Multisport, which delivers an elegant button free experience.

Read: TomTom explodes into the heart rate monitor market with their Multi-Sport

The Mio Alpha’s charm lies on its backside though, which is revealed by turning it over. There are two green LEDs that shine into your skin, and an electro-optical cell that senses the tiny changes in the colour of your skin, indicating blood flow and thus HR. Mio have essentially miniaturised oximeter technology that is found in hospitals in order to produce this wearable fitness technology.


The Mio Alpha needs to be worn a little tighter then your typical watch to enable the LEDs to get a proper connection with your skin. It is activated by depressing the right hand button for around ten seconds in order to get a HR lock. Hitting the same button starts the stopwatch and effectively begins your workout.

The Alpha works to keep you in your HR zone, which is set before the off, and will fire off a series of LED flashes and beeps in order to keep you where you want to be. Post workout you get access to the typical stats, including distance covered, calories burned and average heart rate zones.

Its good, but it isn’t perfect

The Mio Alpha has the potential to be a very very good product, but it isn’t there yet. In fact, in some ways it actually feels like a prototype. A lot of the functions that you come to expect from any basic sports watch are bizarrely missing. You don’t even get a split timer or an alarm, the latter being a feature found on £5 market stall watches. It may not be the most important feature, but it’s pretty much a given to get one.

But it does have some nice features

The inclusion of the pretty new Bluetooth 4.0 Smart is great, allowing it to sync up painlessly without being hard on the battery. Therefore, the Alpha works like a charm with various workout apps on the iPhone 4S during testing. However, there are reports that the process is a lot more troubled for Android users, even on very new models, so Android owners may want to hold fire.


Need to knows

  • The Mio Alpha charges via USB, which delivers around 10 hours of training use or a couple of weeks of regular watch use (not that you would want to do that, in all likelihood).
  • The Alpha compares favourably with regular heart rate monitors with straps, delivering output data within a couple of beats per minute.
  • Mio says “you can wear your Alpha while swimming.” This is not the case though and this is not the device for avid swimmers

Yay or nay?

This is not a straightforward call. This is the best heart rate monitor without a chest strap on the market, but we’re not quite at the stage where there are many to choose from in that regard. Elements are brilliant, but in other places it feels a little rushed, almost like a late stage Kickstarter prototype. At around £150 it is not a cheap option but if the heart rate strap is that bigger deal for you and if you have the money to spare, then this could be a great watch. I think my overbearing opinion is of a product which has boat loads of potential but is not quite there yet.