If you haven't looked at GPS units lately, it may be time to check out the latest innovations which can make these gadgets a helpful aid for endurance riders.

There are two main types of GPS devices -- those whose primary function is "mapping" and those whose primary function is as a "training aid" for sports. Both kinds work the same way in that they operate by receiving satellite signals to orient the unit on the surface of the planet, locating where you are and generating a map of where you have been.

The mapping GPS will allow "trails" to be input in advance that you can follow; these have become popular in cars and trucks to determine routes.

The training aid GPS uses the information it receives to calculate the speed you are traveling and how far you have traveled. Some incorporate a heart rate monitor, and will record this information as well.

The mapping kind is usually handheld (about the size of a telephone); the training aid kind is usually worn on a wristband.

These handy little toys can serve a number of useful functions for the endurance rider:

-- They give you a real-time feedback of speed and distance -- how fast you are traveling and how far you have gone. This may aid you in pacing your horse more accurately.

-- It will also give you a very good idea of when you are approaching important landmarks -- such as water or a vet check. The precise locations -- "coordinates" -- can be pre-set in the mapping GPS, a useful and potentially life-saving function when riding in remote country.

-- Both types will guide you "home" if necessary.

-- Both types can be downloaded to a PC at home to allow you to record your ride.

-- The "training aid" GPS can generate a training/competition log for you. There are several programs for this, many of them available free on the internet.

Software enhances usefulness

Garmin units come with training log software, or it can be downloaded. A helpful alternative is "MotionBased," available at www.motionbased.com. You download a program that enables you to transfer the data in your GPS to their website, where it is analyzed and stored for you. You can invite others to see your ride. There is a "map player" feature which retraces the trail at a speed proportional to your ride (with pauses for water!) as a little inset elevation grid shows the changes in altitude as you progress.

As well as telling you the distance, speed and elevation changes of the loop, there is a display of temperature and humidity for that date and time. It is interesting as you view loops ridden during the day to see how the temperature and humidity change! If you deduct "moving time" from "total time" you can see how long you stopped for drinking, grazing -- even just stopping to look for markings.

The map can be viewed as a line or as a satellite image from Google Earth. The program will generate graphs for any parameters -- speed vs. heart rate, for example, or heart rate vs. elevation. There is a more advanced version available for sale. Another excellent program is SportTracks, available as a free download at www.zonefivesoftware.com/SportTracks.

Again, the program will also download heart rate data (if your GPS includes a monitor) and will allow different parameters and map modes to be displayed.

I believe even the best units are still capable of "losing" a little distance -- they can lose the signal due to dense trees or canyons, or be inaccurate in measuring elevation gains and losses if they can't access enough satellites at once. I think distance is lost on winding trails -- especially if you are riding fast! Older units may not work well in dense trees or steep canyons; the newer WAAS-enabled units are far superior. Check with local users as to the best options for you.

Nevertheless, GPS is still an invaluable (and fun!) tool -- and can make the handwritten training log a thing of the past.

GPS Options

The Garmin "Fitness and Training" units come with a number of options that may be helpful to a conditioning program:

Zones. It is possible to set (or use pre­set) zones of either heart rate or speed. For example, you can define heart rates of 30-60 bpm as resting, 60-90 as jogging, 90-130 as light work, etc. When you download your ride, the program tells you how many minutes were spent in each zone. This gives you an objective report on the quality of your workout.

Workouts (including intervals). You can program into the unit the workout you want to do, including repetitions. For example, walk 10 minutes, jog 20, strong trot 10, jog 20, walk 10. You start the unit at the beginning of the workout and it will beep when it is time to change gait. This is especially valuable for intervals, where you may wish to gallop for a few minutes, trot to recover, then repeat. Beats trying to read a stopwatch! The speeds or heart rates can be downloaded later; you have the option of setting a given speed or heart rate as targets for each phase of the workout.

Pacing. While riding, you can glance at the unit and determine how fast you are going -- a valuable bit of information in itself. But the unit can be used to pace your training ride or competition. Garmin includes a feature called "virtual partner" that you can race against. Say you wish to do a 15-mile loop at a speed of 7 mph. This information can be fed into the unit; when you start the timer at the beginning of the loop the unit will show your progress against a "virtual partner" who is traveling at exactly that speed. The screen tells you how far behind or ahead of your partner you are. The beauty of this is you can (and will) stop for water or grazing, or to open gates, etc. -- but can then attempt to catch your partner. If you get too far ahead, you know you must slow down if you are to stick to your plan. The pace can thus be averaged over the entire loop, regardless of changes of speed in the short term.

Courses. You can identify trails you have ridden before, and ride against your previous performance. You can input markers such as water or road crossings, and the unit will tell you how far you are from the next marker.

It is not my intention to write an advertisement for Garmin -- this is just the brand of my own unit. The fun is in experimenting with whatever unit you have, and finding ways to make the data work for the benefit of you and your equine partner.