From recent advancements in nutritional science to the use of space age composites to build sleds, we can assuredly say that the modern sled dog and musher are safer out on the trail and our dogs are healthier. One of these recent advancements is the use of GPS for mushing. For the last 7 years or so, I’ve been using GPS technology to help me train and race my team of limited class sprint sled dogs.What is GPSThe Global Positioning System (GPS) is a satellite-based navigation system made up of a network of 24 satellites placed into orbit by the U.S. Department of Defense. GPS was originally intended for military applications, but in the 1980s, the government made the system available for civilian use. GPS works in any weather conditions, anywhere in the world, 24 hours a day. There are no subscription fees or setup charges to use GPS.How it WorksGPS satellites circle the earth twice a day in a very precise orbit and transmit signal information to earth. GPS receivers (the handheld devices we will be talking about in this article) take this information and use triangulation to calculate the user’s exact location. Essentially, the GPS receiver compares the time a signal was transmitted by a satellite with the time it was received. The time difference tells the GPS receiver how far away the satellite is. Now, with distance measurements from a few more satellites, the receiver can determine the user’s position and display it on the unit’s electronic map. A GPS receiver must be locked on to the signal of at least three satellites to calculate a 2D position (latitude and longitude) and track movement. With four or more satellites in view, the receiver can determine the user’s 3D position (latitude, longitude and altitude). Once the user’s position has been determined, the GPS unit can calculate other information, such as speed, bearing, track, trip distance, distance to destination, sunrise and sunset time and more.Pace ControlGPS, as most of us know, is mainly used for navigational purposes. In sled dog sports, many of us use GPS receivers to track our speed and distance. The importance of Pace Control in athletic events is very important for best results. Exercise physiologists and professional trainers agree that the longer the production of lactic acid in the body is delayed, the more efficient and more power the body can produce during a session of strenuous activity.In short, this is how it works: Once an athlete’s body, human or dog, goes beyond a certain point of aerobic activity it starts to produce lactic acid as a by-product of using muscle glycogen to produce energy. Once this lactic acid build up reaches a point the body can no longer break it down during exercise and needs rest to recover.Lactic acid is what makes your lungs and muscles burn during high-intensity work outs, and it is part of what slows down a dog team towards the end of a run if not managed properly. Let’s break down any given run into 10 equal distance segments. (represented by the following red boxes)We all know that a sled dog race is far from being a controlled ideal environment, but in an ideal situation each segment would be run at progressively faster rates to allow the body to achieve it’s best result: the lowest time.This allows for the minimum amount of debilitating lactic acid production over any given distance. The discussion of at what particular level lactic acid occurs varies widely by individual, level of fitness, environmental factors and many other things beyond the scope of this discussion. Okay, so that’s the basic short science behind it, but in real life when dealing with a well-conditioned sled dog team on the race trail, it’s often very hard to know exactly how fast you are going. I interviewed Jeff King during the 2010 Fur Rondy Race. Jeff was leasing a team from the Streepers for the event. Although it was the “second string” team for the Streepers, it was still a world class sled dog team, most of the members whom had just finished 2nd place in the Rocky Mountain Stage Race. Because of time constraints and logistics, Jeff had a very limited amount of time to train with and get used to a hard charging sprint team that ran at 20mph vs. the 10mph he was used to with his Iditarod team. I asked him what stood out as some of the main differences between the two aspects of the sport. One of the things he mentioned, and I’m paraphrasing here, you can see the whole interview on, was the fact that with his team, he could judge the difference between 9 and 10 mph, but when you are traveling at the speeds this team moves at, it’s hard to tell the difference between 17 and 20 mph. It was imperative that during training, and ultimately in the race, he knew exactly how fast he was traveling for the very reasons mentioned above.Using a GPS is the easiest way to determine your pace. Terry made sure that every run that Jeff went on, he had the GPS with him. He gave him specific instructions as to how fast he should be going at most points in the race.Each day of that race Jeff started slow and remained steady over the course and came home strong. He eventually finished in 4th place, moving up each day in the standings.Above is the cover of a Sled Dog Sports magazine from September of 2004. The image is of Buddy Streeper from the 2004 ONAC. You can see his GPS strapped on his left arm just below the Canadian flag. This was one of the first units of its kind to be produced, and I believe it is a 2-piece Timex unit.I started using a wrist mounted GPS unit immediately after seeing this photo. The Garmin Forerunner 201 had just come out and it was designed to help runners and marathon racers. Having competed in bicycle racing and talked with professional athletic trainers about pacing and how it related to sled dogs, I knew about its importance. I had tried to understand the running pace of my team, but wasn’t satisfied with using a stop watch and trying to remember the intervals along the trail. Using the GPS allowed me to look at the data for each mile and determine exactly how fast I was going at any given time, or the average for that mile.I was preparing for the Limited North American Championships in 2005, a race I had dreamed of going to and doing well at for over 10 years. I had talked to any musher I could find that was knowledgeable about the course in Fairbanks and what I should be prepared for. The one thing that came up in almost every conversation was not to burn out the dogs by going too fast in the first mile. The first mile of the ADMA trail is a gradual downhill, and the dogs can really build up a head of steam—one that you will pay for dearly in the last mile of the race when you have to climb back up to the finish line.One of the ways I planned to limit my speed was to use my GPS. I started using it at a training trail in the Adirondack Mountains of Northern NY State that had a similar layout in that it was downhill for the first mile and uphill for the last. I have to agree with Jeff King that it is very hard to judge speed the faster you are traveling. There are also other factors that can destroy your sense of speed including proximity to the edge of the trail, proximity to trees, bumps on the trail, etc.I was amazed at the speed difference between the first mile and the last mile the first time I used the GPS. Prior to using the GPS, I already knew I should be dragging my heels for the first mile to slow the team down and avoid over stressing the dogs and possible injury, but I didn’t realize how fast we were going until I had that readout right in front of me. It is very hard to judge a difference of 3 or 4 mph at the start of a run when the dogs are fresh and running smooth. It turns out that we were starting out at 24 mph! This was much faster than I wanted to go, but without the GPS it was hard to judge. The dogs looked smooth and comfortable, as they should look in the first mile of a run, but at the end of the run, they had slowed down to 16mph, with a lackluster middle section.Once I was able to slow them down to a maximum of 20 mph for the first mile of the run, the dogs had more power through the middle of the trail, and most importantly, climbed the last mile faster than ever. Most importantly my overall times for the training runs started to drop. I became a firm believer in using a GPS for almost every training run and race from that point on.Later in the year I applied that same technique on the similar ADMA trail and after hovering around 3rd and 4th place for the first 2 days, I had a great last day, with a strong finish and won the 6-dog event. The advantages of starting slow to finish fast also have been shown in long distance racing. One of the other quotes I remember from that interview with Jeff King was that he commented on the similarities between sprint and distance strategies. He said something like, “We do a lot of things the same, put the strongest dogs in the same position in the team, put the weakest dogs in the same position in the team, and start out slow to have something left at the end.” You certainly can’t win a race in the first ¼, but you can definitely lose it.Below are the day 1 splits from the Open Class race at the Montana Creek Championships this past season. The race was won by Michael Tetzner.The Montana Creek trail is a very flat trail and lends itself well to beginning and finishing interval comparisons.All the teams here started out very fast and finished slower than they started, which kind of takes a crap on all the points I’ve been trying to make so far! Sort of. Each team here is painfully aware of leaving something for the end, but it is not always an easy thing to do with a large powerful team and a windy, twisty trail.What’s beneficial and interesting here is to compare teams against each other. Each split is 1 mile. A 3-minute mile is 20mph—a good average target for a sprint team. Take a look at Tetzner’s splits vs. Christian Taveau’s in the first column. Christian ended up in 2nd place. Christian started out with a 2:42 and a 2:49:a blistering fast pace. Tetzner, although starting out pretty fast himself, but not as fast as Christian, was able to go faster in the middle of the run and towards the end. Some of his middle intervals were faster than previous ones whereas Christian’s team was progressively slower in each lap. Tetzner won this race in the final 2/3 of the course.The diagram on page 23 shows the splits from the Tok Race of Champions back in 2006. The blue and red teams ran the 8-dog class (I’m the blue team and Rob Downey is the red team) and the yellow team was Buddy Streeper in the open-class.Tok is also a very flat trail that is good to measure your starting intervals against the finishing intervals because it doesn’t change much in elevation over the whole course.You can see that the blue team was the slower team for the first two intervals, but by the 3rd mile it started to turn faster intervals than the other two teams. What should also be noted here is how fast Buddy’s open team was going for the first 8 miles—very close in speed to the 8-dog teams although he eventually would be running twice the distance!Below was the third day of the 2006 ONAC. This was a classic Egil vs. Buddy battle. Leading after 2 days, Buddy starts out faster than Egil—take a look at the first 5 splits, vs. the last 5. Egil came from behind and won this race in the last 5 miles of the last heat. In short, it can be very hard with a dog team to run an ideal race with decreasing split times as the the miles tick by. But by striving to get there, we can increase the performance of our dogs.NavigationUp until recently, the use of GPS for navigation was illegal in both of the world’s premiere ultra-marathon sled dog events, the Iditarod and the Yukon Quest. The Quest was first to “cave” and allowed its use just a couple of years ago. The Iditarod now requires all competitors to carry a GPS signaling device that allows online real tracking of teams, although that decision was probably more of a marketing one as opposed to a safety precaution. During the race, fans could watch the race unfold from the comfort of their home or office. The Iditarod race in 2011 will be the first to allow use of personal GPS receivers on the way to Nome. In 2003 or 2004, I attended a sled dog symposium in Maine where Martin Buser was the keynote speaker. I asked him what he thought about teams being allowed to use a GPS during the race and he said he thought it should be allowed. He didn’t agree that it should be against the rules, and went as far as saying that someone may die some day from an event that may be avoided if GPS were allowed. I thought it was ironic that during that first year that selected racers were carrying their GPS tracking devices in the Iditarod, that Martin put his on a plane and we got to watch his “team” travel at 300 mph in a straight line back to Anchorage! I guess a sense of humor is critical while driving a dog team 1,000 miles across some of the most remote landscapes in the world.I’m sure there are many different opinions on why GPS navigation units should be allowed or not, but I can’t see many cons. Is it part of the sport that a musher could get lost because of a poorly marked trail or because a marker blew down, or a series of markers gets taken out by snowmachine? Is it a race to see who has the fastest dog team over 1,000 miles or a canine orienteering event? Does the GPS contribute to a musher and team’s safety, or does it give them a false sense of security? I’m sure there are as many opinions about it as there are mushers.Whatever your opinion, a GPS can be an incredible tool to navigate with, after all it really was what they were designed for. The addition of speed and timing that we discussed earlier was really because of the demand from specific sports groups. My personal opinion is that anyone going into the backcountry without one is taking unnecessary risks. However, the knowledge of how to use a compass and topographic map are also critical and should be learned whether you carry a GPS or not.This brings us to the point of whether or not all this so called “safety” technology is creating a false sense of security by providing a safety net for those who venture out in the snow and cold with little or pitifully low survival knowledge.In this day and age, a back country explorer doesn’t need to learn to read land marks as they appear on a topo map and doesn’t need to learn how to adjust a compass reading for magnetic variation. Until the batteries die. DevicesOne new development, literally in the last year or two, is the addition of GPS in smartphones. There are literally hundreds, maybe thousands of different apps for the Apple iPhone and other GPS enabled smartphones. There are some pros and cons to using your phone to track your speed and routes. Some of the pros are that generally you can find software that is very specialized and/or customizable for the data that you want to keep track of. One of the downsides is that using the GPS on your smartphone can be a big battery drain.Another neat thing is that some of these apps allow you to keep a web page with all of your data, maps and comments online for no additional charge. This is the app (next page top) I was testing last winter for my iPhone. It is called iMapMyRide.There is a free version, but with the $4.99 version you get the website upload capability. Each time you finish a run it uploads your info to your page on its website where you can share it with friends and compare your runs over the same trail. With one click you can upload it to the social networking site of your fancy. One great feature is the 3D fly-by view of your course.I used iMapMyRide+ to map out the Tozier trails in Anchorage. Below is one of the trails we used for the Raven Electric 10-dog race last year. It is overlaid on a Google city map. One click away on the website is the same run overlaid on a satellite image of the area. Notice the numbers along the route. I’ve customized the settings to record data every 1 mile, just as most of us do with the dedicated GPS units. One fun thing about using this software with the iPhone is that it will speak the data to you if you plug in an earphone.I tried this and it was quite useful, contrary to what I expected. I could just put the phone in my pocket, run the earphone wire up inside my jacket, and every mile a lovely woman’s voice would chime in, “1 mile, time 3:05. Current speed 19mph. Average speed last mile 19mph, etc. You can set it to tell you just the information you need, which is not to be confused with the information you would like to hear.I hope I’ve shed a little light on a vast subject. Even though we participate in a very traditional sport, and many of us do this because of the simplicity of traveling through the woods quietly in a traditional way, technology has a way of slowly creeping in.I’d also like to say, that the use, or overuse of a GPS while mushing can also be a problem. If you find yourself looking at the little screen for answers and not looking at your dogs, you can be making a big mistake. First and foremost as mushers and dog trainers we have to be able to read our dogs. Every day is different, every trail is different, and even every run on the same trail is different. We can’t run our dogs on the cold hard data of a GPS and some hard fast rules about how fast we should be going. The GPS is only another tool we have, but by far the best tool we have for judging the well being of our team is our own judgement and expertise.SafetyObviously the knowledge of where you are in the wilderness is safer than not knowing. Having a GPS and a way to communicate your position to authorities can save a life. The photos above are from Donald Eriksson in Sweden. He runs Aurora Borealis Adventures. A couple of years back one of U.K. clients suffered a severe heart problem during a tour. They had to call in an air evacuation. Donald said, “Because I had my GPS with me I could give them the exact position. That’s the reason I always have my GPS with me on my tours.”FunOur friend Carol Kaynor in Fairbanks sent me this map (above) of her “dog yard mileage.” “From my GPS, a map of my travels through Bonnie’s dog yard. Between hooking up three teams of dogs and walking puppies, I covered a total of 3.22 miles. I think the GPS coordinates form a new kind of artwork!” •Greg Sellentin is the publisher of Mushing Magazine and an aspiring open-class sprint and stage racer. This story originated as a presentation for the ADMA Sled Dog Symposium in Fairbanks, Alaska 2010.


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