It is just a little device that you slide onto your ring finger and let it settle on there for a minute or two in order to get its reading.This pic is just an arbitrary reading I chose from a morning last week but below I will give a brief description of what each number means.
On the top line you can see my blood oxygenation level (Sp02), which is reading at 95%. The highest you can be is 100% oxygenated and a 100 is the most optimal for being able to perform the best you possibly can as an athlete. The more oxygenated your cells, the better your muscles can fire, thus hitting higher paces, power levels, etc. When your Sp02 level is lower, it is more difficult to reach high levels of exertion as your muscles and brain aren't operating as efficiently. But there are a variety of things that will affect your oxygenation rate- training load, stress level, altitude, time of day, etc. and these are things that you can figure out as your track yourself daily with the MightySat.
The bigger number on the bottom left or "PR" stands for Pulse Rate. Your pulse is a good number to track throughout your training and day to day to see how you are recovering. If your heart rate stays elevated long after a hard workout, or if you can't get your heart rate up for a certain workout, these can be indicators of being fatigued, tired, or overtrained.
The upper right smaller number is "Rrp" and stands for your respiratory rate. This number is basically measuring the rate of breaths you are taking within a minute (usually between 12-20 breaths for an adult). This number is giving a rate of oxygenation (Sp02). Basically, it is proven that with slower, deeper, more oxygenated breaths, we can deliver more oxygen to our muscles, organs, and brain. If we are stressed, not breathing as well or effectively, then our Sp02 level (the big number on the top left) will be lower, which then affects our muscles and their ability to fire, as well as our brain and its ability to function, make decisions, etc. You can control the Rrp as you use your MightySat and can practice deep breathing exercises to see how this is affecting your circulation, blood flow, and overall oxygenation.
The middle smaller number is "PVI" and stands for Pleth Variability Index. This number is a marker of fluid responsiveness, and thus has some direct correlation on how hydrated you are. There is still research being done on this tracking number but in tracking personally, it's very easy to see when it's high, I'm usually a bit dehydrated. When it's low, good to go:)
The bottom smallest number reads "Pl" and stands for Perfusion Index, or basically your blood flow levels. A higher number means higher blood flow rate or circulation.
To be perfectly honest, I wasn't really sure of my MightySat's usefulness in the first few weeks of using it day to day and tracking those numbers. What I mean is, I didn't exactly change any training or effort levels given the numbers I would see in the morning, or after a hard workout, etc. I just kind of tracked the numbers and generally saw around the same figures most days. When I was initially given it, my friend, mentor, and huge advocate of it, 2012 London Silver Medalist, Dotsie Bausch, explained how she used it in her lead up to the London Games in track cycling. If her Sp02 was extremely low, then she would completely adjust her training by taking a day off, or just a super easy day until her Sp02 number was back up to 98, 99, or 100% showing that she was recovered. Or, the same would apply if her Pulse was off from its normal levels, indicating overtraining or fatigue. From my initial use of the device, I wasn't seeing any readings above 95 and 96 with my Sp02 reading, even if it was following a recovery day. On top of that, I train 3 different sports and it's quite impossible to just keep taking days off until my levels went up. So, I just kept tracking my numbers, not really adjusting anything with my training but just seeing how the numbers were reading. It wasn't until August 22nd at 9:59am that I had an "Aha!" moment with my MightySat.
Here was my reading: