John Galea's Blog

My blog on Gadgets and the like

Heart rate variability

I recently tripped across a concept I had never heard of called heart rate variability. It measures the actual distance between heart beats. As much as we think our heart beats at regular intervals it does not. And oddly the more regular the heart beats are, the less healthy we are (according to studies I read). HRV can measure mental/physical stress, and can tell us when we might be over training. Now in all the reading I have done I am not sure I have a firm grasp on what this all means, but I can start with the technology side of things. Once we have the data then we can scratch things (your head … other things :)) to figure out what exactly it means. I won’t address the topic of what is HRV, or how to interpret it, I will address it from a technology point of view. There are lots of articles on HRV written by medical professionals who have a lot more cred than I. So on with the tech …

First off you need an accurate heart rate monitor. Optical ones won’t do. My Scosche for example is not supported. So your looking at a strap. The Wahoo TICKR as well as the Polar H7 both will fit the bill …

I have not found any watches that do HRV (My polar A300, Fibit Blaze don’t). I am sure one somewhere does … So that leaves us with an app. I am on an iPhone for now. I quickly zeroed in on three apps. HRV+ (free), Elite HRV (free), and SweetBeat HRV (paid). Sweatbeat even offer a free onetime HRV evaluation of the data you have uploaded in the price. Both Elite and Sweetbeat upload the data to their server (HRV+ does not).

One of the first thing I noticed is that HRV, like your heart rate can vary quite a bit, so a longer sampling gives you a more accurate reading. How long? Well I worked with all three apps for over a week and found the biggest variation (on average off by 19%) to be on the app that took the HRV for the shortest, which is HRV+ at only a 60 second reading (Vs 2 or 3 minutes). Interpreting the data is key, and HRV+ did nothing but give you the raw data. As such, I would have to say give HRV+ a pass.

Moving onto Elite HRV I would have to say this app is by far my favorite of the three. It’s free, and who doesn’t like free! It also attempts to help you interpret the data and gives you a simple visual. The raw HRV is there, it quantifies it, compares it and even reminds you if you miss your morning HRV reading. The visual graph should help you determine if your HRV is too low, too high or just right (no references to children s books needed). A track record is really important to the apps ability to help you know where you are at physically/emotionally. You can do HRV readings anytime you want and your history data is kept for you. As a tool goes I think Elite HRV is the best of the three. The one thing that is missing is a web portal to see the results that have been uploaded to the cloud … So if there isn’t a web portal why am I uploading my data? Elite on average was within 10% of Sweetbeat.

Last but not least is Sweetbeat HRV. I bought this after watching a video from one of the founders that went into the work they had done to correlate Sweetbeat with EKG machines. I was impressed (I drank the Koolaid). Couple this with the fact that Sweetbeat will do a manual analysis of your uploaded HRV and it seemed like a good choice. What is missing is a nice visual showing your HRV like Elite does. Oddly there is a second app from the same company for $6.99 that does give you that called DailyBeat HRV.
They do show you your HRV throughout the session:
And a plethora of data on your HRV that if I had no idea what to do with HRV, I REALLY have no idea what to do with this:

As much difficulty I had getting correlation on HRV (between the apps) the other data that comes out of these apps like RMSSD (Root Mean Square of the Successive Differences) was completely all over the place. Without some believable data what the heck do I do with it?

There is a portal to log onto to see your results but it is basic at best and provides little to no tools to help you do anything with the data over and above what you get on the phone.

So tool wise there you have it. Now all I have to do is figure out what it means? I have noticed it definitely detects when I am run down, not feeling great, slept poorly etc, but do I need an app to tell me that? Maybe I should just go low tech an buy a mood ring 🙂 Maybe as a weekend warrior I just don’t need this level of focus?

I put together a how to use HRV follow up blog post following this one.


June 29, 2016 Posted by | iPhone/iPad | Leave a comment

Tempered glass screen protectors (a mini post)

Over the years I’ve bought a few screen protectors. I have hated most of them. Orange peel textures, bubbles/dirt under them, distortion to the screen, reduced sensitivity to touch etc means as a whole I had given up on them.

Recently a bud of mine Lance bought a tempered glass screen protector and I was hugely impressed. Instead of a film like texture these are thicker and more rigid. They are completely clear, the finger glides over them naturally and there is absolutely no difference in touch responsiveness.

I noticed recently I had somehow aquired a few scratches on my iPhone 6. No idea how. So I bought one from JetDirect on Amazon for my iPhone 6. I actually bought two just in case I messed it up installing it. They were cheap like $10 for the two. It came with a sticky lint remover, a screen cleaner and the protector itself. First up you clean the screen as good as you can. Then polish it with the soft dust free cloth they provide. They give you a sticky lint remover but honestly packing tape works even better. Just go over the screen a couple times removing as much dust etc as you can. Cleanliness is paramount. The slightest piece of dust or hair and you have a mess on your hands. The protector comes with two pieces of tape you put on the front of the screen. This allows you to remove it and reposition it. There’s a thin film on the back of the protector that has to be removed, and is clearly identified on the back. You can lift the corner back up, reposition, reclean if needed and next thing you know you see the protector slowly adhere to the screen. It really is amazing to watch.

Once on the protector provides some additional rigidity to the screen against drops, as well as protection from scratches. It can even hide small scratches on the screen (it did mine). In the even the protector gets scratched it can be removed (tossed out) and replaced with a new one.

The one I bought was off by about 2 mm in size and barely covered the screen. Take some time and read reviews people have posted before buying.

I also bought one for my iPad mini and it was also from JetDirect and fit the iPad perfectly. Getting the screen completely clean took a ton of patience and time (Ok I admit Lance did it). Once in place it is invisible. Really quite amazing. I highly recommend them! Thanks Lance!

June 28, 2016 Posted by | iPhone/iPad | Leave a comment

Garmin Edge 305 review (take 2)

Dedicated followers may recall that I previously reviewed this device. Sadly I lost it not long after I got it so didn’t really get to totally explore all it’s features.


Currently I mountain bike with a Garmin Foretrex 401 and love it. The navigation is excellent, takes AAA batteries (so you can carry a spare set) and connects to ANT+ heart rate and wheel/cadence sensors. It has enough memory for 500 waypoints (the only device in this category even today). The large number of waypoints means I can carry all of the locations I go in memory and not have to preload them. 5 years later it’s still a fabulous device. It’s starting to show it’s age, the battery connector got bent. And my number one disappointment with this device is that it basically ignores the wheel sensor and always uses the GPS for speed/distance. Now on a road bike where your pretty straight this doesn’t make a huge difference but on a mountain bike where you are winding around constantly turning it can be off by a fair amount, think 10-30%.

To get around this I bought a Garmin FR70 just to record (and display) the data from the heart rate monitor and wheel/cadence sensor. Although I have to say I ignore cadence (the rate of rotation of your pedals). The FR70 has no GPS in it.

So I grabbed this Edge on ebay. The device has an ok size of screen, but given the size of the device Garmin has not made good use of the space on the display. Like a number of us, my eyes are not getting any better so having an option to have a larger font is nice, sadly this is missing on the Edge. It is however extremely flexible in terms of what is on the display. Completely customizable as most Garmins are. They do this very well.

The Edge connects by Ant+ to wheel/cadence sensor as well as heart rate monitors. Ant+ has the ability to transmit to multiple devices at the same time. A very nice feature. Now if you buy a dual band device (ant+ and bluetooth) you can add in connectivity to your phone as well. I’m on an iPhone. When I was on Samsung it too had Ant+ and the flexibility that offered was amazing. To check the wheel size I mapped out a route on Google using there distance calculation and then rode it and compared (once I manually set the wheel size).

Neither the FR70 or the Foretrex allow any kind of alerts for things like heart rate. Eureka, it’s there on the Edge. And very configurable. You can set a min/max heart rate and be alerted if you cross it. The Edge alerts you five times with a nice albeit annoying beep and then shuts up until your back in range. It really works well. If there is anything I wish Garmin had done was to make it easier to turn this on and off.

Waypoint memory size is limited to 50 you you have to pick and choose which to save. And if you add another one when it fills, it starts dropping ones off using some incredibly intelligent (I can only guess) method to it’s madness.

Navigation on the Edge is excellent. Well for the most part it is. You can navigate to a saved waypoint and it will show you a big display showing direction and distance as the crow flies to that way point. Garmin have always done this well. They have improved the usability to track back to the start and it shows your with a nice beep everywhere you need to turn to get back. Shows distance and time to get there. Perfect right? well on the road yes, but totally useless on a mountain bike path filled with turns. It just kept beeping at me telling me a turn was coming up. Ya how about you tell me when there isn’t one? And there is no way to silence the alerts (that I’ve seen). Oh well … There are two things on the Foretrex Navigation they didn’t include on the Edge. If you press and hold button on Foretrex you can navigate to a waypoint. On the Edge you have to press numerous buttons to get to the same point. On the Foretrex it remember where on the list of waypoints you last selected, on the edge it goes to the top of the menu each time. A little irritating.

I also noticed the Edge the map only shows the points on the map for the current lap. On the Foretrex it showed even past rides. I can see both good and bad in that.

The unit runs on an internal rechargeable battery that is charged by a mini USB port. So sadly you can not carry a spare battery and you better remember to charge it, or you may find yourself on a trail in the middle of nowhere with a dead GPS.

The Edge has heart rate alarms which you can use to insure I don’t spend too much time maxing out your heart rate. I either slow down, control my breathing or flat out stop. Using the alerts I have managed to lower my max heart rate by 20-30 BPM which has to be healthier. Similarly using the low alarm you can remind yourself when you are dogging it 🙂 I love this feature and it will become a must have on future devices.

The Edge comes with two nice mounts making it possible to mount it on two bikes. And there are two different bike profiles you can setup and choose from. I had to dig to find how to choose the bike profile and eventually just stumbled on it (press and hold mode). The bike profiles allow you to set the bike’s weight (I have no idea what it does with that), as well the size of the wheel (or auto). I don’t really trust auto so set my own. I had read some reports that the Edge can fall off the mount so I put an elastic around it to the handle bars as a precaution.

The Edge unlike the Foretrex will always favor speed/distance from the wheel sensor! And in fact, there’s even a GPS off mode for using on a trainer. And next time you turn it back on it turns the GPS back on for you.

The screen scratches REALLY easily and is flush so if you drop it …

Once back in the house you sync your route with Garmin connect (their portal) using the Garmin Express app. It works Ok, but I am kind of disappointed it does not sync over ANT+. Firmware updates are also done this way.

Garmin do include an app called Basecamp to allow you get and edit your data (waypoints, maps and routes) to/from the Edge but this app is pretty poorly done. I prefer the older Garmin Metroguide.

I did have an issue with USB 3 on my laptop not working correctly with the edge. The way around it was to put a USB hub in between, odd but manageable.

So all in all I like the Edge, it’s discontinued now but there are lots around on ebay etc so dirt cheap!

June 23, 2016 Posted by | GPS Stuff | Leave a comment

Shinecon VR headset mini review

I’ve been super curious about VR headsets. I’ve seen the ones from Samsung and wondered about them. So I found this one which fits my iPhone 6 and comes with a clicker to control the phone.


First up comes content. VR, 3D, etc are all names for different forms of displaying 3D content. When you go to the movies or have a 3D TV in the house they rely on glasses that refocus an image that on it’s own is out of focus and in so doing creates a 3D image. As an example here is a Youtube video I thought was pretty decent.

This type of headset, is basically a more elborate Google Cardboard. It relies on side by side distortions to create the depth. So if you play it without the 3d what you see is two side by side movies. There’s lots of content out there for this type of headset. Everything from movies, to Youtube. You just need to look for the buzz words SBS (side by side), Google cardboard, 180 degree VR etc. Because of the side by side what you seeing is quite small (think half of a screen). The overall effect definitely gives a perspective of depth, but is no where near as immersive. You don’t get the holy crap that ball is going to hit me I better duck feeling you do in a movie theater. Some of the effects however are quite good.

The headset itself is simply a holder for your existing phone. This one folds down in the front you clip your phone in close the door and away you go.

The headset is placed on your head and projects in front of you. Since you are playing from your phone, your device needs to be handle the demands of the specific movie. The headset is by no means light and the weight is quite noticeable. I found myself holding it with my hands to reduce the weight/discomfort. I have a hard time imagining watching a 3 hour movie with it.


The bluetooth clicker that came with the phone is fairly limited in use on the iPhone. Since the iPhone does not support a mouse you are pretty much stuck with open the door, start the clip, quickly close the door, quickly slip on the headset and away you go. To say it is clumsy is an understatement. This would be a whole lot easier on Android which supports a mouse.

You quickly run into the next challenge, the menuing system for whatever your going to use, be it Kodi, a Youtube video etc all are (of course) not 3D. So your navigating a bizarre looking image. I found it best to close an eye or focus on one eye.

On iPhones you run into a number of additional challenges (beyond the mouse). Storing local content is problematic (although not impossible) and getting Kodi on your iPhone is also non-trivial. Of course none of these are an issue with Android 🙂 Ya ya …

In the end, for $40, it amused me for a brief period of time, and satisfied a curiosity. I am not sure how much I will use it, but been there done that got the t-shirt 🙂

June 10, 2016 Posted by | iPhone Stuff, Mutlimedia | Leave a comment

Waze app review

Waze is a cross platform (iOS, android, web) app, I’ve played with it on a number of occasions and uninstalled it each and every time. More on this to come. Waze allows you to use it as an in car navigation tool (with traffic data provided by fellow users), with the ability to have you share your eta and live location with friends. There’s a social side allowing you to message folks near you (a bizarre concept for someone driving) as well as report gas prices, traffic conditions etc. Once you’ve set a destination it allows you to send an email or text message with your eta. Over email it sends a link that allows someone to watch you to live follow you on your progress to your destination. This feature alone is amazing.

The app is very much single purposed, driving. Forget it for walking, cycling, public transit or any other method of transport you can imagine … yes even flew powder trips can not be tracked :).

The app shows you traffic on your route as well as locations of the po po, red light cameras etc. This data is entered by users and pulled from their devices (even when they are not using the app). And this is my first rub with the app. The end user can not control the apps use of location, data etc. It’s either always on or always off. Very bad.

They have added the ability to manually turn off the app but you have to think to do it.
IMG_1173 IMG_1176

If the other person has waze as well they can follow you in the app. Text message just gives a one time eta. The navigation app works fine. You can load the app onto a phone and tablet but the history is not syncd between the two.

If you allow Waze to access your facebook friends those using waze immediately appear on your friends list.

One of the things missing on the app is the ability to request a users location, like you can using the find friends app on iPhone.

Over all it’s a good app, great search, navigation, traffic. I just wish for more control on it’s use of my battery/data and the ability to request the location of missing loved one late or MIA.

June 5, 2016 Posted by | Uncategorized | 2 Comments