GPS routes advice…

GPS.  You’re doing it wrong.

Do you use a GPS to train, race or navigate on the road, trails or in the hills?  You’re probably not using it to its fully capacity – which is fine, we rarely do use everything a manufacturer gives us.  I can speak from experience (not mine thankfully) that a failure to correctly use basic information (pace or distance) displayed leads to missed cut offs and DNFs.  This then gets manifested at poor race directors as complaints of poorly measured courses.  I have first hand experience of the following points that seem obvious when written down but during a race they are extremely frustrating!

1. Total race distance minus distance run does not equal distance to go.  The further you run the more this becomes apparent.  Off-road this effect is magnified.  In a 10 mile race if you have run 3 miles there are almost certainly not 7 miles to go.  It is almost impossible for a race to be measured short unless it is short.  The exception to this is running on a track or tight circuit when the GPS may take a shortcut and cut corners.  If you have loaded a course or route to follow onto your device then you should use the distance to go function.  It is frustrating not being at the checkpoint when your GPS says you should be but the ground doesn’t lie!  

2. Device distance to go does not equal distance to run.  You will need to run further on your watch than the course says for the reasons above.  If you think about running (or walking) up a steep hill – the measured course may go straight up but the route may zig zag which adds distance, slows your pace and costs you time.  There is not much that you can do about this except be aware of it and use it in your planning.  If you are running at 8 min/km you are not getting a Km closer to the finish every 8 min.  You need to manually watch how you’re progressing against the distance to run.     

3. Breadcrumbs GPS tracks do not replace the need to navigate.  Do you trust @IamLostintheMountainsHelp whose route you downloaded to have plotted the route points correctly? Are you sure that the GPS track loaded is of good quality and doesn’t take a short cut over a cliff?  How confident are you that your GPS signal is in the right place and not jumping around (we’ve all run at 3 min/mile before)?  GPS routes in breadcrumb form are an aid to navigation but do not replace the need to carry proper navigation equipment or the ability to use them.  

4. The recommended route is not 100% accurate.  The recommended route provided by many events nowadays are usually created from a previous user’s data.  If you are running off trail the chance that the same trod is still there is slim.  GPS accuracy is poor in forests so that left turn may not be in exactly the same place.  You should use the breadcrumbs as a check and navigate by other means.

5. Finally, don’t forget to look up.  Not just the positive message from Ben Fogle’s Himalayan adventure but great advice for navigation.  Just because it’s electronic and in colour doesn’t mean it can be trusted.  Look up.  Focus on the leg goal.  Check the compass.  Check the ground.  I have seen people trying to work out what was displayed on a tiny screen as I described the route leading to the summit and next check point.  I wasn’t using black magic or even the map at this point.  I knew the CP was on the next summit and looking up I could see the obvious path weave upwards through the ominous crags.  Look up.      

6.  Strava lies to you.  Oh and when you finish understand what you’ve logged.  Strava runs are based on moving time.  Set type to ‘race’ and watch your total time appear!

I recommend DC Rainmaker’s website for more detail on GPS.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s