With all of the running apps available for smartphones to track your distance and pace you might ask yourself do you really need a separate running watch?

While the power of free and minimal cost running apps such as RunKeeper, Daily Mile or Endomondo has grown over the past few years there are some distinct advantages to a dedicated GPS watch.

Data Collection/Reporting

The type of data recorded and what you can do with it is similar between both apps and GPS watches.  Both options will provide you with core functionality of your current pace, distance traveled, elapsed time, a map of your route and other metrics to measure your performance over time.

It is the actual functionality of the two options while running that makes a separate running watch the preferred choice.

Two Tests of a Phone App vs. a GPS Watch

I recently conducted my own test of biking 5 miles with an iPhone 5, a Samsung Galaxy Nexus and the Garmin Forerunner 210 along with a CatEye Strata bike computer with a sensor on the wheel.

I performed this test on my road bike instead of running so I could have an accurate control distance with the bike computer attached to the wheel so the actual ground covered was recorded.  This is the same method used to issue USATF running race course certifications (wheel measurement).

Only the Garmin matched the bike computer within a margin of .01 miles.  The iPhone and Samsung Galaxy Nexus both over reported the distance traveled and pace substantially.

Bike Computer (Wheel sensor): 5.00 miles
Garmin Forerunner 210: 5.01 miles
iPhone 5 (with Runkeeper): 5.32 miles
Samsung Galaxy Nexus (with Runkeeper): 5.29 miles

For runs of a mile or two this may not be a big deal, but if you run longer distances over 10 miles the results can be running over a mile or more less than the phone has reported!  That 20 mile marathon long run you might do could end up being more like 18.5 miles.

What’s worse, your pace is being reported incorrectly.  You will have a false sense of your performance capability and learn of this on race day when you run a measured course only to find your phone has betrayed you!

In another test, I wore both my Garmin Forerunner 210 and used RunKeeper on my Samsung Galaxy Nexus during the 2012 Chicago Marathon.  The phone was strapped to my upper arm with a clear view of the sky.  Downtown Chicago presents tough challenges for GPS devices.  The tall buildings can bounce signals or block them entirely causing measurements of your location several blocks away or zig zagging across the city.

Extended underpasses such as the one at the beginning of the race block GPS entirely for nearly half a mile.

The results?

Garmin Forerunner 210: 26.58 miles
Samsung Galaxy Nexus (with RunKeeper): 27.93 miles

I personally believe the Garmin recorded my actual distance covered due to any weaving or not running the exact course line over the course of the marathon.  If there was any error due to the buildings or other obstructions it was minimal.  The phone was not even close.

There is nothing worse than finding out your pace is not what you think it is or how you trained on race day when you discover your phone has over reported all along.

Issues with Running Apps

Reduced Accuracy
The GPS sensors vary greatly between different phones.  But the one thing that holds true today is they are less accurate than a dedicated GPS running watch that is specifically designed to capture precise movements.  While this is reported universally among runners I wanted to see for myself.

Phones are less accurate than a GPS watch for a variety of reasons.  The most common reason is due to the compact form factor of a phone along with all of the other antennas and circuitry inside there just isn’t enough room to include a more accurate GPS sensor.  In some phones, the type of sensor used might also vary, but that is beyond the scope of this discussion.  GPS watches have a larger GPS sensor as a critical component.

For a phone, the GPS is designed to give a very good indication of your location, but not a pinpoint. Compounding the problem, phones do not take a continuous recording of your location but rather frequent “snapshots” in time. These data points are then connected by the shortest distance between the two points. This is why quick movements, turn arounds or tight turns are often cut off when reviewing phone GPS data on a running app.

Finally, the algorithms used to calculate distance traveled also vary in phones.

Phones are not designed specifically with accurate GPS distance measurement in mind the way a running watch is.   A phone is a Swiss Army Knife.  It can do a variety of things, but not all of them very well.

Tracking Progress While Running
A big issue with running applications is viewing your distance, pace, time elapsed and possibly heart rate while you are running.  Typically your phone is strapped to your arm or on a waist belt out of easy sight.  Running apps have tried to counter this shortfall by having computerized voices periodically announce your pace and splits over your earphones if you are listening to music.  But what if you don’t listen to music?

You will have to physically wake up the screen and make a concerted effort each time you want to check your progress.   Even if you do listen to music I find the announced intervals are not often enough to stay on track if you are monitoring your pacing.

A running watch is always within easy view without altering your running form and provides immediate feedback of your run.  Pacing is easy to determine at a glance.  It is always on and nothing to fiddle with.  There is a reason a phone’s screen turns off while running which brings up the next issue.

Battery Life
Today’s smartphones can do a lot, but battery technology has not kept pace for their energy demands.   A running app is not only constantly using the GPS of your phone, but also the data plan in order to update maps and sync data.

Other features such as social network sharing or uploading to websites can use even more battery.  I haven’t even mentioned the draw of the battery for that big screen and any other applications the phone is running either such as your music player and countless apps in the background.

If you plan to run longer than 2-3 hours your phone may not make it through your run leaving you without a way to call for help if needed and leaving you flying blind for the rest of your run.  Not good!

GPS running watch batteries can reliably capture 8-10 hours or more of activity and can remain on standby over a week.  In other words, more than you will need!

Data Plans
Use of a running app requires a data plan on your phone.  With many carriers limiting data use or families sharing plans this can add up.  While a running app may not consume a lot of data, it consumes more than a GPS running watch that uses no data plan!

Indoor Use
If you want to record your running on an indoor track or even a treadmill forget it with a smartphone.   Your phone’s GPS will do you no good indoors.

GPS watches are equally useless indoors, but many can be paired with an optional footpod that can record everything with a good degree of accuracy, except for plotting on a map where you ran.  You simply keep on running!

I’ve owned both Polar footpod devices and Garmin footpod devices and find the Garmin devices perform really well compared to Polar.

Even better, for instances where GPS may be blocked (such as the half-mile underpass at the beginning of the Chicago marathon), a footpod serves as a secondary data source that is automatically tapped so you are never running blind waiting for the signal to return.  Other runners will be in the dark.

Our Take

It is our recommendation that if you are serious about your running and want a tool best suited for the job it is a great decision to invest in a GPS running watch.  If you are just starting out and want to get a feel for the type of data you can record about your runs you can start with an app and then transition to a watch later.

Running apps are powerful but are just not accurate enough to be used to train reliably.  This again is no fault of the app designers, but limitations of phone hardware.  They also are inconvenient for measuring real time progress while you are running.

The watch I personally train and race with, along with many elite marathoners such as Ryan Hall, is the Garmin Forerunner 210.

In considering a running watch, there are a lot of features, functionality, styles and form factors to consider.  I use the Garmin Forerunner 210 as it has just the information I need and enough functionality to train effectively.  It can be enticing to have a running watch with more bells and whistles but in the end it is just different ways of reporting the same data.

All you really need is distance, time elapsed, pace and possibly heart rate and cadence if you use those to train.  When you get home you can easily upload all of the data and analyze your run and progress while recovering!

One App That Will Enhance Your Running

There is still one app that can enhance your running and isn’t affected by GPS. Our FREE Runner Academy Podcast app will deliver top training information directly to you including interviews with expert coaches, authors, elite runners and others along with actionable tips you can immediately implement in your running. Listen when you run, at the gym or commuting.

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