14 October 2018

How to get more accurate optical (wrist) heart rate readings ...

Optical (or wrist) heart rate technology measures heart rate via LEDs that track blood flow under your skin. The accuracy of measurement is influenced by a number of factors and varies by person, their individual differences and by sport. 

In this article, I will write some tips to get the most accurate measurements from your device. It is extremely important that you wear the watch properly.


Suggestions for wearing:
1. IMPORTANT - To measure wrist-based heart rate accurately, you need to wear your watch snugly on top of your wrist as high as possible. Experiences show that the best position is about 1-2 fingers above your wrist bone. It looks quite strange at the beginning, but believe me, it is the most important rule. The sensor must be in firm skin contact, but not too tight to prevent blood flow.
I will repeat - wear watch fairly tightly and about one finger above the wrist bone!
Check distance from watch to wrist bone on the picture above.
Check how much a watch should be tightened on the picture below. Otherwise, the watch will slip from its best position or sensor won't be able to read your heart rate properly.


2. Wear your watch at least a few minutes prior to starting the heart rate measurement. This ensures your watch provides stable readings.
3. Avoid too cold skin. It is a good idea to warm up the skin if your hands and skin get cold easily. Get the blood going before starting your session! When exercising in cold temperatures, your body attempts to keep your core body temperature stable by directing the blood flow from arms and legs towards the core of your body. This reduction in blood flow to the arms can make it more difficult for the sensor to measure heart rate accurately.

Additional information:
The chest strap is always a backup solution. My Polar M430 works excellent with a chest strap (Polar H7). Especially in sports where it's more challenging to keep the sensor stationary on your wrist or where you have pressure near the sensor, I recommend using a heart rate sensor with a chest strap to get a better measurement of your heart rate.
And don't forget that some sort of people simply has more problems with wrist heart rate measurements: skin with tattoos, fat people, hairy skin ...

Your comments are welcome.

09 October 2018

Polar M430 - Optical HR Sensor Accuracy - Part 2/2

As you can read in this article, I have a lot of problems with Polar M430. To be more precise the problem is with an optical HR sensor. The mentioned article has many readers every day, so the logical conclusion is that I'm not alone with bad optical HR readings.

After a mentioned article was published I got a lot of comments and suggestions from readers from all over the world. Nothing helped and almost surrendered. I bought a Polar 7 chest strap and all problems went away. Well, it still bothered me because the bought item didn't work as expected. And I often don't want to bother with a chest strap or I even don't have it at hand.
Before I write an article, I want to talk with Polar support. From four emails (to global support, to German support and to Slovenian support) I got only one answer with - as you can expect - usual corporate answer. You know what I mean: polite answer where said that they are happy to answer me and with similar suggestions like in User manual.

Weeks and months with problems were behind me when a new type of error occurs. Look at it:

This type of error occurred suddenly after 70 minutes of training. It simply stops showing a number. I stopped at the top of the hill and dry the hand, move watch, change hand, tried on wife's hand ... it simply didn't work. It was very close to throwing the watch away. And to be even more pissed off, it starts to works again when I came home.

So after some months, I tried again. I checked Polar's website for service. And guess what - the problem starts on their website. As I'm from Slovenia, I tried with www.polar.si and I can see this:


It looks like they don't have a redirection to their main site where Slovenian site is available.
But there were hidden another bug:

After a click on Service button, the page reloads and again and again ... I simply can't find where is service for Polar watches. Maybe you think that I should use a button for e-mail? I tried that some months ago and I'm still without an answer.

After asking on forums, I got an address of service. For all Slovenian Polar users - it is Urca in Ljubljana. They kindly accept my loved watch and asks me if I can send them some TCX files.

Without the watch, I decided to use Polar Flow with a chest strap. And guess what? A Polar's main application doesn't support it!! You can use a Bluetooth cheat strap Polar H7 with other application, but not with Polar Flow. You have to install an additional application on your phone - Polar Beat. Only Polar knows (do they?) why Polar Flow can't work with a Bluetooth chest strap. I have talked with some friends and they confirm me the same outrage.
Polar Beat is a simple application and its functionality should be integrated into Polar Flow. But even if it is simple, users expect Start, Lap, Pause and Stop. But not with Polar Beat. There is no Lap button! And when you want to stop training, you have to use a Pause button first. OMG.
Polar Beat - can you find a Lap or Stop button?

Otherwise, it works as expected and it automatically uploads results to Polar Flow. Again - why two applications instead of one?

Polar Flow on the web is a fancy, but it is far from what older PolarPersonalTrainer offers. And besides that, it still shows childhood diseases. Just for an example:


Why Polar didn't update a PolarPersonalTrainer with many useful functionalities (comparing trainings for example)? I don't know.

After some days my lovely M430 comes from service. It gets a new HR sensor (a short remark from service was written by hand, so I'm not sure if its name is BCASE). I immediately went to a short walk in a forest with M430 on my hand. The first hour with new sensor looks promising and I barely wait my usually climbs.

At first minutes, I was a little disappointing. The first minutes doesn't show an improvement. The measuring starts with a usual delay (showing much lower HR then real). But now it starts to work properly within five minutes. It isn't good, but it is a little better.
You can see the problem here:




But I found another problem when I came to the top. Instead of falling down, the HR jumps as hell - only on the watch of course). This (unimaginable) wrong readings were on display for some minutes.

It looks that changing HR sensor didn't help. My conclusion is that Polar M430 has a real optical HR problem when my body drastically changes behavior. This is when my heart starts to work much harder or slowing down from the effort.

Yesterday I found another problem at home (not on training):


An information for readers who think that I don't know how to use this watch. I have tried many positions on my hand. Cold and warm skin. Upperside and downside. Left and right hand. Shaven hand. Dry or wet skin. Full battery. Clean sensor.
Nothing helps except wearing a chest strap. With a chest strap, it works like it should.

Conclusion:
As I write before, the main problem is when the heart starts to work much faster and when it slowing down quite fast. Don't understand me wrong. I'm a Polar user for almost twenty years and until M430 I didn't have many problems. My point is that buyers of optical HR watches are aware of potential problems and check if it works on their hand.
It would be nice to test if new Polar Vantage with new optical technology works better. Polar - can you provide me a test Vantage V?
Don't miss an article: How to get more accurate heart rate readings?.

UPDATE (10th October 2018): Polar discussion forum is no longer available. That is the reason for preparing a Polar unofficial forum. You can register and start with conversation ... welcome. Who will be the first one? :-)

11 September 2018

GPS Android road navigation - Google Maps (2018)


After four years it is time to check Google Maps again. Last years were turbulent on navigation market. Faster devices, better communications and connectivity, cloud solutions...
Google is one of the major players when services for a broad number of people comes into play.  Their Google Maps (not only on phones) becomes an unofficial standard when people want to see a map, check the location, prepare a route to destination ...
Let's look at some characteristics.

PRO
+ Online maps are often updated and you don't have to wait for new map release. Maps are available for almost all world, so users don't have to deal with some clumsy map packages. If you want to explore a world on a map, you don't have to look any further.
+ Excellent search engine leaves competitors far behind. Fast and with Google's effective adjustments for concrete user really shines. You don't have to know an address, just start typing and results are shown. After the desired result is selected, you (generally) get the address, phone, reviews, (sometimes live!) occupancy, opening hours. If you want to read a review, reviews from users and Google's Local Guides are just one click away.

+ Street View and Satelite View are very useful features to see the real situation. It isn't available everywhere or in full quality, but the most interesting parts are usually covered.
+ The most accurate Live Traffic at the moment. If something happened on your way, you will be notified and rerouted. More information about Live Traffic in this article.
+ Synchronization between devices is really instantly. You can prepare a route on your computer and then send it to your phone with one click. Besides that, all history searches are seen on all devices (if a user is logged in of course).
+ Application is available on many devices (computers, phones, tablets, car radio/Android Auto ...).
+ Navigation is very good with quick rerouting if necessary. 
+ Application opens and works fast, without battery drain. Navigation can use PIP (Picture In Picture) mode or works without navigation - just with real-time traffic info. One-handed gestures are supported.
+ If we leave privacy besides, navigation is totally free. 
+ Fantastic combination with real-time public transport (where available). A simple click on Transit button shows nearby train and bus departures. It instantly calculates the best combination of different transit options and shows if your bus/train is on schedule or delayed.
+ Some places like stores, airports or hotels have indoor maps and photos.
+ Real-time sharing location to friends. Can be useful. For example, you don't have to be asked where you are at the moment and how long you will need to the destination. 
+ Sending feedback to Google. Reporting missing roads, roadworks and other problem are simple. My experience is that feedbacks are taken seriously and usually shows in one or two weeks. Probably response time depends on the importance of location and type of correction. Google's feedback works much better than any other services I tried. And because Google Maps works online, your feedback will be seen by all people.
+ You can define some of your favorite locations (Home, Work ...) and Google Maps will show distance and time necessary to that location all the time. If the traffic location will change, the color of time will change from green to orange (or red). 
+ Tight integration with Google Assistant. Many commands can be executed with your voice. For example, you can search for nearby gas stations or restaurants while driving. 
+ Developers can use almost all features of Google Maps in their applications and websites with a Google Maps Platform
+ Google announces augmented reality Street View mode to help you follow directions in real time, along with personalized recommendations to help you discover places in your surrounding. 
+ We can hear rumors that Google will integrate Waze Incident Report (road closures, accidents, police cars...) to Google Maps.


CONS
- If you drive a camper or truck, you won't get all the important information. 
- Speedcams are not supported. Otherwise, you can use TomTom Speed Cameras which works excellent with Google Maps.
- You won't see all the roadworks on the map. In some countries, only those reported by users are shown, but we are sure, that Google will improve this in the near future.
- Searching for POIs at the destination isn't very convenient.
- While driving it is helpful if navigation shows two actions ahead. The latest versions use this feature more, but there is still a place for improvement.
- A user can download an area and navigation is also available there. But if you don't have an internet connection, Google Maps isn't very useful (you won't get traffic information for example).
- Privacy consideration. Should I have to write something more?


OTHER
- You can help Google (and other users) by reviewing the places you know well. After some time, you will be awarded.  Maybe with early access to new Google products, participation in exclusive workshops, get some free place on Google Drive ...


CONCLUSION
In the last two or three years, Google Maps becomes a number one navigation tool for me. It is really useful, easy to use and available on almost all devices with different operating systems. Google Maps really makes navigation experience better and easier and I can't find a better service right now. I can highly recommend it for almost everyone who needs a navigation, information or just for looking on a map.
It is hard to understand that some car company still integrate their own audio/navigation system without a support for modern connectivity. All new systems should have Mirrorlink support or a support for Android Auto (and CarPlay).


Rating: 9/10 (check whole rating table)