Several of my friends use exercise recording apps, particularly for walking, running, and cycling. I had a look at a few options, but found two that seem to have broad appeal. These are RunKeeper (which is not just for running), and MapMyFitness (also known/available as iMapMy, and in specialised form as MapMyRun, MapMyRide..)
Update: most have switched to Strava, and I now use iRunner, described further down.
These apps allow you to:
- Record start and end times of various sport/exercise activities
- Record your path, including speed and altitude, using GPS built into an iPhone or Android device
- Listen to music while exercising, with periodic voice-over announcing your progress
- Set goals and report your progress
- Report statistics on your activities, including e.g. monthly totals, fastest time on a route, estimated energy spent
- Accept data from capable heart rate monitors, pedometers, sports GPS recorders etc
- Share your activities and favourite routes with friends (who are also members), and/or the whole world.
- Publish your achievements on Facebook and Twitter
My aim here is not to give an exhaustive review of these products, but to point out a few differences and share my experience.
Cost
RunKeeper have recanted on the “with ads” approach and now offer a single app without advertisements. Paid membership increases the range of reporting available from their web site.
RunKeeper’s site is clean and fairly straightforward.
Strava takes a similar approach to RunKeeper. Paid membership unlocks goal tracking, more reporting and analysis.
iRunner / iCardio is free for basic function, which includes ability to upload your workouts to Strava and RunKeeper accounts. In-app upgrades are very affordable. You can “go pro” for all features (about $10), or just add options for external sensors (like a heart monitor), custom routines, and fitness assessments more cheaply.
MapMy is free (with ads). Paid membership removes the advertisements, and higher subscription levels provide extra reports, printed maps, training plans, and priority customer support. The first paid level, “bronze”, is $30 p.a.
If you don’t want to pay $30 each year, you will find the iMapMy web site heavily bogged down with animated advertisements. Apart from the annoying visuals, it makes the site slower to use, as the animations often load before the page displays properly.
If you do pay, the MapMy web sites are transformed into something much more usable and navigable.
Value
It’s hard to beat the value of “free”, though I hated MapMy’s web site in free/advertising mode. iRunner’s upgrades are so cheap it hardly matters. Looking at the fully paid versions, Strava looks the most expensive, but if you’re going to pay a monthly or annual membership you’ll want to look in more detail at the features available. Each system is a little different.
Ease of use
Both products take a little fiddling to work out, but I find RunKeeper just a little more intuitive to use.
Mobile Features & Capability
MapMy seems a little more sophisticated. The most notable difference I’ve found is support for multiple laps in a run or ride. Both will allow you to record a path that contains multiple laps, but only MapMy will treat them as laps of a circuit and allow lap splits. Edit: Strava does this better.
Finding / sharing routes
RunKeeper makes it easy to save a mapped activity as a “route”. You can then select this route when using it again, and hence compare times. Routes can be shared with friends. Searching for routes only shows those published by my “street team” (list of registered friends).
It doesn’t seem to work the same in MapMy. I found it rather confusing, but the answer may be in their new web site (currently in “beta” testing) with the new “courses” feature. Registered users can switch between the old and new sites until the new one is finalised. Searching for routes in MapMy shows many results from all users. However, it doesn’t seem to search by location very well.
Online support
Each product has a support forum, accessible after you have registered. I can appreciate that providing end-user support to many thousands of users, for GPS-using software running on mobile phones, would be quite a burden, and many issues may actually be completely unrelated to the software. MapMy appears to have a good commitment to participating and answering questions. RunKeeper seems a bit overwhelmed.
Battery
Any mobile phone will consume more power while using its GPS receiver. The same goes for apps that access the internet. Keep this in mind when planning longer runs or rides.
Previously: MapMy has a problem causing continued heavy battery use after you stop using the app. That’s right, record an activity, end the activity, and switch away from the app, and the battery will continue to run down — not quite as quickly while actively using GPS, but enough to flatten a newish iPhone’s battery overnight. I normally get 2 days including plenty of talk time. Users on their support forum report the same thing occurring on Android phones.
The workaround is to force the app to close. Normally, apps remain open in the background on both iPhone and Android. On iPhone, double-tap the “home” button, and the bottom row of the screen presents a scrollable view of open apps. Press and hold one of them, and they will show a small red “x” above them. Then you can tap an app to completely close it. Press “home” again to return to the normal view.
Don’t be too hasty with this workaround. iMapMy is very web-centric; if it hasn’t yet sent your activity data via the internet, force-closing the app means losing your records.
Update: I hear this may have been fixed around October 2012.
Strava
Members of our club have taken to Strava, which seems a mature system. It supports only two activities: running and cycling*. The iPhone app seems a little basic, with no voice announcements, no screen rotation, and a display of average but not current speed, though serious riders would have a speedo / bike computer / sports GPS, and probably not be wearing earphones.
At first I was surprised there’s no distinction between road and mountain biking, but found you can list specific bikes and nominate which one was used on each ride. I would like to be able to do this in the iPhone app though.
The web site features have clearly had a lot of input from serious enthusiasts and competitors. Most notably, rather than simply calling a whole run or ride as a “route” which can be shared and re-used, Strava supports segments. A segment could be a hill climb (or descent), a loop, or any other section travelled. The great thing is they are detected automatically. Having completed a run or ride, any included segments are listed with it on the web site, along with your time(s) for the segment, indicators of your best times, and your rank among all Strava users on the same path.
Since it distinguishes segments from whole runs/rides, I can ride to a meet, compete several laps of a circuit with breaks (tag-team) and ride home, all recorded as a single “ride”, yet am able to compare the actual circuit laps.
* Update: Strava now supports walking, windsurfing, skating, swimming, various skiing and other nordic activities..
iRunner
(Update: section added Feb 2013)
I got a heart rate monitor for Christmas, and started looking into how it could help me train. This led me to prefer Digifit iRunner to record my rides and runs. It features a number of ways to report your progress with popup and lock-screen alerts, and configurable voice feedback. iRunner’s configurable dashboard is great; large fonts for a quick read! DigFit has a good recording and reporting on its own web site, but iRunner also allows upload to 7 other fitness sites, as well as social media like Facebook. This means if you or your friends have committed to Strava or Runkeeper ecosystem, you can get the benefits of iRunner without losing your results or your friends. There is one notable omission from the upload list: MapMy isn’t supported. Also, the upload has to be done manually (a couple of screen taps) at the end of a workout. It’d be nice to have this made automatic, but that would be tricky if you then want to edit/annotate a workout as it’s already been sent.
iRunner is free, though some features depend on paying a modest in-app fee to upgrade.
While Runkeeper and Strava can record heart rate, iRunner and the DigiFit site are particularly focused on “cardio fitness”, with reporting on time spent in different heart rate “zones”. Clearly you need a compatible heart rate monitor to get this benefit. Sensor support does require a paid upgrade to the app ($2.99). Your maximum heart rate is configurable. Default zones are fixed at 50-60, 60-70, 70-80, 80-90, 90-100%, but you can make your own; some trainers recommend different ranges.
iRunner can give voice feedback on heart rate. I soon found the alerts annoyingly long, as they stated not just the band, but the minimum and maximum heart rates for the band (in bpm) every time. Thankfully, the makers added an option to turn that off, so now it can just announce “entering band 4″. That’s much better when learning the discipline of an all-aerobic workout.
iRunner has companion editions, iBiker and iCardio. “All our apps offer the same multi-sport functionality. There are small differences in initial defaults and quotes & tips oriented to the name.” iCardio is the only one available for Android phones.
Heart rate & training recommendations
Here’s some sites I found useful:
- http://www.digifit.com/Heart-Rate-Zone-Training-2.asp
- http://www.cycling-inform.com/heart-rate-training/73-how-to-use-heart-rate-monitor-and-zones-to-improve-your-cycling
- http://www.runnersworld.com/running-tips/how-use-heart-rate-monitor?page=single
- http://answers.yahoo.com/question/index?qid=20100223055826AAJFSN3
One interesting snippet from the Yahoo answers link:
A better measure than heart rate while running is how quickly it recovers. After you run, time your heart right at the end, at 1 minute, and at 2 minutes. The faster it recovers, the better your conditioning.
iRunner includes a “cool down” feature, which ends the “session” but shows a graph of your heart rate for the next 2 minutes. The cool-downs are recorded to DigiFit, but are not part of the workout uploaded to other sites like Strava.
Overall
MapMy seems a little more capable than RunKeeper, and better supported. Handling of “laps” almost convinced me to switch from RunKeeper. The battery problem convinced me not to.
RunKeeper is a little easier to get started, and if your aim is “what can I get for free”, a much nicer site. It supports a very broad range of exercise activities, with goal-setting and social media bragging accountability. RunKeeper is a good choice for general exercise alone or with friends.
If you run or ride with a club, or competitively, Strava does it better.
For voice feedback on heart rate, a large-font dashboard, use iRunner.
If you’re willing to spend some money for a comprehensive package but still don’t know, then use iRunner but also set up accounts on Strava and RunKeeper. Send your data to all of them, look at what they tell you, and look at the upgrade options. Then buy a bike computer or training watch, with GPS and heart rate sensor, and upload to any system you want.
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If you have used these or other such programs, please feel free to add your perspective below..
The question
While standing on a friend’s roof recently, I noticed some houses had photovoltaic (solar) panels oriented differently to others. Another friend said his solar installation quote had an additional item to achieve a better angle than his existing roof provides. It got me wondering:
- What is the best orientation for fixed solar panels?
- How much does it matter?
- Is there benefit in having different positions for Summer and Winter?
Working it out
We start by looking at the sun’s path. For our purposes the earth is a sensible frame of reference, and we’ll consider the sun’s apparent path through the sky.
The University of Oregon has an online tool for solar path charts, but we really need numbers for modelling. I found Greg Peletier’s spreadsheet (1), which includes solar path and related solar radiation models.
Starting with solar azimuth and elevation, I added a calculation for the angle of incidence of solar radiation onto a panel, for specified panel orientation. I chose to focus on two dates: one midway between the Summer solstice and an equinox, the other midway between Winter solstice and an equinox. These give an approximation of typical Summer and Winter conditions.
All calculations unless otherwise noted are at 30° South, an altitude of 220m, assuming flat terrain.
Daily solar incidence, Summer and Winter, for various panel orientations
The major horizontal groupings are panel azimuth. Minor divisions are panel elevation.
The vertical axis is the day’s average of cos(θ), where θ is the deviation of the sun from directly facing the panel. It’s calculated as the angle between two vectors, but eliminating any time the sun is below the horizon or “behind” an elevated panel.
The lower graph shows the Summer + Winter values combined, though the units are now incorrectly scaled.
I found this graph curious, as it shows a well-positioned panel can see near as much direct sunlight in Winter as it might in Summer. While the Winter days are shorter, the sun’s path is a tighter curve, not moving as far away from the panel axis.
However, angle of incidence isn’t the only issue at work here.
Atmospheric Influences
The aforementioned spreadsheet also contains a model (2) for solar radiation onto flat ground, compensating for atmospheric reflection and diffusion. Starting with the energy loss of a direct beam through the atmosphere, we see an expected reduction in Winter.
Vertical units are W/m².
Adding diffuse radiation (the light that shines in the shadows), the differences diminish. I reduce the modelled diffuse light collection by (panel elevation / 180°), which seems reasonable but may be inaccurate.
Caveat
Bird and Hulstrom’s model is for total solar radiation. Photovoltaic (PV) cells work with only a portion of the radiated spectrum, so electric energy yield is much lower than the numbers stated. Atmospheric effects would vary with wavelength, so the actual characteristic may be somewhere between the graphs above, or may be even more attenuated and diffused than shown here. If anyone can identify a more appropriate model, I’ll consider reworking this analysis.
Observations
Let’s zoom in on 3 sets of orientation: Due North (ideal), 30° (my home), and 75° (friend’s home, an extreme example). I’ve also added calculations at each solstice and an equinox.
- Regardless of azimuth, Summer favours a horizontal panel.
- The closer to North, the more benefit could be gained in Winter by tilting the panel
- Even 75° away from North, a panel on a common sloped roof should perform well in Summer, though not so well in Winter.
- The stacked totals on the previous graph show surprisingly little variation through a wide range of positions.
- With a panel elevation of 20°, there’s only about 10% annual difference between facing North, and facing due East or West.
For my home, 30° from North-facing, I assessed three elevations through a whole year. These are monthly totals, not single days.
Taking the best option each month, I get an average of 273 W/m². That’s only a 4% improvement over a fixed installation at 20°, which doesn’t really warrant the effort of making panels adjustable, and moving them every few months.
Other Factors
- Shade! Nearby trees may be a problem, especially in Winter.
- Elevation difference to roof can be a help or a hindrance. Mounting a panel more horizontal than the roof it’s on could cause it to be shaded at times. On the other hand, panels could be angled to take advantage of light reflecting off another part of the roof.
- Heat can be a problem, depending on the type of panel. Monocrystalline and polycrystalline solar cells perform poorly when hot, so ensure panels are mounted such that airflow under and around them is unhindered. Amorphous cells are not so affected by heat, but degrade over time. They are cheaper but correspondingly less efficient; for the same power, and the same money, they require twice the space.
- I’ve ignored cloud and smog. If Winter is typically more cloudy than Summer, positioning should be tuned more toward Summer.
- I’ve assumed that the aim is maximizing total energy collected per year. If running a home entirely on solar power, it’s probably more important to optimize for Winter.
- I’ve assumed time of day is unimportant to the end user. If generated electricity is priced differently throughout the day, or there’s insufficient energy storage/sharing to distribute the generated power, that would matter.
- This is all about a fixed installation. Where space is available and other power sources are expensive or unavailable, a tracking system would be much better. House roofs are less suited to tracking systems, as one panel would likely shade the next, defeating any gains. A roof with a long North-South ridge could host a tracking array at the top quite effectively though it would have to withstand additional wind in that location.
Disclaimer
I am not a solar radiologist. I am not a solar panel installer (though I suspect few of them would have better than a pre-printed list of acceptable angles, if anything). My analysis has not been reviewed by any recognised scientist nor authority. I have not verified any of this empirically. Do not base commercial decisions solely on the advice here. My analysis was conducted for a specific latitude, making several assumptions; I have tried to identify the major ones.Bibliography
1. Solrad.xls by Greg Pelletier of the Washngton Department of Ecology, available from http://www.ecy.wa.gov/programs/eap/models.html
2. Bird and Hulstrom’s model from the publication “A Simplified Clear Sky model for Direct and Diffuse Insolation on Horizontal Surfaces” by R.E. Bird and R.L Hulstrom, SERI Technical Report SERI/TR-642-761, Feb 1991. Solar Energy Research Institute, Golden, CO.
Last year, One Guy’s TV stopped working. After much to-ing and fro-ing, it was determined that yes, it was still under warranty, at just over 2 years old. The power supply board had a problem, and Samsung organised a replacement board with the local authorised repairer.
A few weeks ago, I repaired our DVD + Hard Drive Recorder. Today I repaired our older DVD player.
The short story
A lot of electronic equipment and appliances have an expected lifetime of only a few years, due to a particular inexpensive component, which can often be replaced.
The technical story
The capacitor is a basic and very common electronic component. Capacitors come in a variety of constructions, but those with greatest capacity are mostly cylinders of aluminium foil with an electrolyte between the layers. For a while, the preferred electrolyte was polychlorinated biphenyl (PCB), which worked well, but was highly carcinogenic. Not good for workers in component factories, nor anyone else who came in contact with the internals of a capacitor. Now a much safer chemistry is used, but it’s nowhere near as durable.
Broad applications
My employer makes a habit of requiring a 3 year warranty with all new computers bought. There was one model, of which we probably had 50 PCs, where every single one of them developed a hardware fault within the warranty period. They all had a telltale sign: “bulgy caps”. The tops of the electrolytic capacitors were bulging, indicating the capacitor was coming apart.
This was the problem with our TV.
Our DVD+HDD recorder recently failed. Occasionally it had taken a while to start up, but this became more frequent until it just gave up. It was out of warranty, so I took a look. Sure enough, two bulgy caps on the power supply board. So, I went shopping online for replacements. RS-Online have quite a range, and make it easy to compare specifications. Looking through the options, I noted something interesting: even the best, most expensive parts had a rated lifetime of 10,000 hours. If an appliance is left on all the time, that’s not much more than 1 year! Of course that’s a minimum expected lifetime, and is also dependent on voltage, temperature, and other factors.
TVs and DVD players are designed with a “standby” mode – reduced operation but able to be powered up using a remote control. Clearly, some parts must remain active for this to work. The bloke who fixed the TV said this is why TVs etc should be turned off at the wall when not in use.
Ok, so the other DVD player. It worked, but would freeze about 53 minutes into a movie. That’s about the point where the laser has to refocus onto the 2nd layer of the disc. I cleaned the lens; no improvement. I watched it start up with the cover off; the laser assembly was moving up and down appropriately. I did notice on the power supply board, one capacitor looking slightly bulgy, and another one had a brown deposit around it. Another order, replace those 2 caps, and this player is back in business too! It still has a problem with one particular disc, but otherwise appears to be back to normal.

Rubbish
Last week at the tip, I saw quite a range of electronic equipment piled together. (Our rubbish tip doesn’t charge, but does segregate waste types and restricts what can go into landfill). It made me wonder.. how many TVs, stereos, DVD players just need a couple of capacitors changed? How many microwave ovens only need a new magnetron?
On the same trip, I found in the “green waste” (garden) section, a portable electric fan, new in box. Its problem? One leg was missing.
Economics
One of the downsides of production lines, automation, and cheap labour in distant countries, is that many items can are cheaper to construct something and ship it around the world than to repair or maintain. I could buy a basic new DVD player, as good as our older one, for $50. If I were to pay a technician to repair and test a DVD player in this state, it might take half an hour if he had the right parts in stock. I doubt the bill would be less than $50 for labour plus $10 in parts, and there’s the risk of other problems making it a bigger job.
Or, for $120, I could buy a new Blu-ray player that also accepts data cards from cameras, and recognises photos, songs and movies stored elsewhere on my home network.
So, mostly people accept the lazy economics of “just buy a new, better, replacement”. Even more so with printers, which are sometimes so heavily subsidised that a replacement ink/toner cartridge costs more than the printer itself.
Appliances could have greater longevity. They could be upgradeable. They’re not, because consumers are more focused on the up-front price. And, people are lazy in their affluence.







