In our SUP and prone paddle training programs, we strongly recommend training by heart rate. With the demise of flat heart rate straps (most vendors seem to be moving to the “puck” type straps) heart rate monitoring during paddle workouts is essentially impossible for the prone paddler as they are laying on their sternum for all or part of their workout.

Mio Alpha is a new type of heart rate monitoring device that does not require a chest strap. The only device needed to monitor heart rate is a wristwatch. Unlike traditional heart rate monitors, The Mio Alpha uses” light beams and an electro-optical cell “sense” the volume of blood under your skin. Sophisticated algorithms are applied to the pulse signal so that the heart’s true rhythm can be detected.”

We held off for a while primarily because of the horrendous (swim)  review over at Gizmodo . For us, the only important factor was whether or not it worked in the water while we were paddling.  Our results were (largely)  different than the Gizmodo review which is a good thing.

Testing of the watch happened in three phases.

Phase 1: Cross training: we used the watch on all cross training rides to compare it to the “gold standard” of our Garmin heart rate monitor. During all cross training activities (cycling, easy SUP paddles, and walking the dog) the Mio performed “in sync” with our Garmin. Although the exact heart rate numbers were different (e.g. one watch would say 163 and the other would say 159) the trends were similar and each watch was consistent in the reading trends. More on this later.

Phase 2: initial testing in the water . According to Mio, the watch is waterproof as long as you do not push any buttons while you are in the water. Fortunately, there is no real reason to push any buttons in the water because all it does is measure heart rate (more on this below). Our initial testing was (largely) promising. For the vast majority of our time paddling the Mio worked well. The heart rate measurements seemed reasonable and varied with our exertion. Once or twice during each paddle, however,  things would go haywire and the heart rate reading was whether extremely high (e.g. HR 185 while easy paddling) or extremely low (e.g. HR 95 when doing an interval). The good news is that when Mio was giving bogus results they were obviously and remarkably bogus. There was no confusion that it was “a little bit wrong” which would be much more damaging to your training. If things were “a little bit wrong” that could mean the difference between going too hard or too easy on a workout.

Phase 3: Secondary water testing when compared to Garmin: Again, we used our Garmin as our gold standard. The results were similar to what we found previously. The two watches were “in sync” with trends but the exact heart rate number varied between watches. This variation was in the range of 1-5 beats at any given time. Additionally, every once in a while the Mio did not have correct readings and would be 20-40 beats different than the Garmin. The Garmin seemed to respond to changes in heart rate faster than the Mio but this was not always the case.

Conclusions:

• For the prone paddler: Given that it is essentially impossible to train with heart rate if you are a prone paddler (because the heart rate strap is a torture device) the Mio is considered to be a critical training tool for the prone paddler despite the shortcomings of giving intermittent bogus results. The Mio is recommended with reservations.

• The diferent calculation of heart rate between the Mio and the Garmin is interesting but not a deal breaker. Remember, when training with heart rate, you are looking for trends in your exertion level relative to your LT or max heart rate. You do not really care what the exact number is. As such, even though a Garmin may be reading 154 and a Mio is reading 151 that is of no consequence IF you know your heart rate ranges for each product. It seems that the absolute heart rate measurement is different between the two products so users are encouraged to perform an AT test using the heart rate product you will be training with. Stated another way, your Garmin AT might be different from your Mio AT.

• For the stand up paddler: Remember, when the Mio is not submerged in water, the heart rate function worked on par with our Garmin heart rate monitor. If you are only looking for a heart rate function and you do not need GPS (or a simultaneously displayed stopwatch or clock), and you do not want to monkey with a heart rate strap, Mio is a good choice. If, however, you are a paddler who wants to paddle with your your shirt off, the Mio is a critical addition to your training kit. As far as we are concerned, paddling without a shirt while you are wearing a heart rate strap is an unacceptable  fashion faux pax. The Mio will let you train with heart rate, get a tan, and you wont look like a triathlete while you do it.

Additional comments:

• Our only other comment regarding the Mio alpha is similar to what you will find on other websites and reviews. The major complaint we have is that because you cannot push buttons in the water, the interface is leaves us wanting. When in heart rate mode, the display displays ONLY your heart rate. As such, it is somewhat difficult to use this device to do intervals (e.g. there is no stopwatch) or even time our workouts (e.g. there is no clock.) To have a stopwatch or clock to assist with your training, you will need another device with you during your paddle. In the long term, we hope that they change the interface to at least allow for a clock and/or stopwatch to be displayed simultaneously with heart rate.
• The Mio Alpha has a lot of other functionality with regard to apps, charting progress etc. We did not test any of those functions. Please visit the Mio website for more information about what is possible with the Mio Alpha watch.
• This review reflects the experience of a single test subject. We hope that other paddlers have a similar experience but it seems that there may be some variablity (hairy wrists affecting results?).  Please let us know if your results with the Mio Alpha are different.