Huge advances in technology have made equipment that was previously unaffordable and hard to find more readily available to runners. Portable 'Global Positioning System' receivers, or 'GPS' as they are known, can have real benefits for runners, enabling you to track your exact location, on or off road, plan your routes and review your performance. This is great news for anyone who wants to be able to accurately monitor their training, share a route with running partners or even study the course before the day of a race.

What is GPS?: GPS refers to a group of 24 satellites, which were set up and are maintained by the US Department of Defense. These satellites transmit very low power radio signals allowing anyone with a receiver to determine their location on Earth. GPS technology has progressed beyond the military uses it was created for since being made available for civilian use in the 1980s.

How does it work?: A GPS receiver tracks the location of these satellites and picks up coded information to find their exact position. The distance of the satellites is calculated by a simple formula - simple in GPS terms, but too complex for this ezine! Once the GPS unit has 'locked' onto enough satellites to calculate your whereabouts, the information is stored in the memory and you can start navigating.

Where can GPS be used?: GPS now has many recreational uses and is particularly beneficial for running, walking and cycling. Any activity where it's useful to track where you are, navigate to a specific location or know how fast you're going can benefit from GPS. You can record or create locations from anywhere on earth and GPS will help direct you to or from these points. Of course, there are some places where it is impossible to receive the satellite signals, such as inside buildings and underwater. GPS works best when you have a clear view of the sky.

GPS for runners: A GPS unit is a must-have for any runner who likes to know exactly where they are and how far they are running. Pedometers measure distance by your stride length, which decreases as you tire, so any readings are only approximate. A GPS unit can pinpoint your exact location, plot out routes, calculate the distance you've run, give altitude readings and current, maximum and average speed-readings.

Which GPS should I use?: The Garmin Forerunner 301 continuously monitors your heart rate, speed, distance, pace and calories burned enabling you to train smarter and more effectively. Whether you are a serious athlete or just want to see tangible results in your running, the Forerunner 301 can help. The compact wristband has an embedded GPS sensor with navigation capabilities to show you how far you have run, how fast and how to find your way home! There is also a 201 model available without the heart rate monitor and 'Training Center' software.

GPS on a new level: Some GPS units, such as the Garmin 301 above, have the ability to download route data from CD-ROMs or mapping software. Map data can be very detailed, showing major and minor streets, tourist attractions, off-road trails, close-ups of the terrain, aerial views, and more. With Memory-Map software, simply connect your Garmin GPS to your PC using a PC interface cable, select map areas on your PC screen and download the information to your GPS.

Memory-Map: Would you like to plan your running routes more accurately? Memory-Map software allows you to view colour maps on your PC, create waypoints, routes and tracks, and transfer them to your GPS unit. Entered a race? Re-create the course from the map provided and discover exactly where the hills are, study the terrain through aerial views, and get precise measurements for mile markers. Memory-Map software is available for a wide range of regions of Great Britain. Details...

Plan routes: Plan your routes, on or off road, with the click of a mouse before you go running using Ordnance Survey maps, A to Z road maps and aerial views. Check precise distances for sections of the run and the complete run, check for undulations using interactive hill profiles, view a 3D terrain so you know exactly what to expect or even follow the 3D fly through feature. If you're planning to run this route with a group, you can share the route with other Memory-Map users, either by email or by making it available to download from a website.

Using the maps: You can print off maps in the scale of your choice, either to memorise, share with others or take along with you so that you don't lose your way. You can add notes to your maps, highlighting areas of interest or any tricky sections. If you run with a Garmin Forerunner or other GPS system, transferring your route directly into your GPS will give you a fully functioning navigation device. As you run, your GPS unit will show you your exact position en route and log where you've been.

Performance review: After the run, you can import GPS information back onto your PC, enabling you to review your run and see exactly where you went. View charts that show you what speed you were running on all sections of the route and where you hit your peaks and troughs. This really gives you a fully interactive training diary!