99% of runners wear one. But how do you race well with your running watch and use it to help your performance?
Be careful! If there is one piece of advice I can give you, it is this. The watch is NOT 100% accurate, and you could finish your marathon having run 26.4 miles (or more!). It doesn't mean the marathon is long, it just means that is what your watch thinks you ran on the day using the GPS signal it received. You can't stop the race when your watch hits 26.2, with the finish line 200m in the distance and say "right that is me done", it doesn't work like that.
I did some analysis of the London Marathon a few years ago from runners using Garmin watches. Of the 156 results we looked at, the average distance people ran for London Marathon was 26.45 miles. On average, the Garmin was 0.9% out on the distance over the course of the marathon. Of the 156 pieces of data we collected, 16 units gave a value less than the race distance, 3 gave exactly 26.2 miles and the other 137 units all gave a value over 26.2. So, expect your Garmin to over estimate how far you’ve run.
To best use the watch on race day, treat your watch as if it was a basic stop watch.
Start the watch as you go under the start line and press 'End' when you go over that finish line!
"I want to know how fast I am going" I hear you cry. Well, this is where the 'Lap Button' comes in. It's look varies on each watch, on the garmin it looks like an oval shape with an arrow in it, and it can be your best friend. Depending on how you like to race, will depend on the frequency of the use of the lap function
I will probably set my screen up on the watch to show me total time and lap time (as long as you can edit your screens with your watch)
In a 10km, I will press the lap button as I pass each km marker. This way I know the pace I ran for the last km and can work out if that is on target, a bit above or a bit below, and will also know my race total time. If I want to run a 40 minute 10k, I know I'll need to be running 4 minutes per km, and be at 5km in 20 minutes or just below. This will give you accurate pace for the course you are running.
A word of warning, some races aren't very good at putting their mile or km markers out, I famously ran a 3 minute mile in one race, because the markers were so out of place. In those sorts of events it can help to take a quick look at your average pace for the run, to get an idea of where you are at, as it is better than nothing.
In a marathon, I will take my laps each 5km. This allows me to get enough running in that I'll know how fast I have gone, but also it is short enough so I can make adjustments. I'll know how fast I want to run each km in, and because I am lapping it each 5km, the lap number resets to zero, so at 7km I just need to know how fast I wanted to run 2km in and then I'll be able to adjust accordingly.
I am able to do this from the training experience I've built up. I have a good understanding of the various effort levels I can run at, how long I can sustain them for, and also have a firm idea of what pace I am looking to race at.
Having a pace band can be really helpful here. These little bands break down the race and tell you at what time you need to be at each mile. Especially for longer races like the marathon, your brain can become rather tired later on. Doing simple additions can take a lot more work than usual. To avoid this, have the time you need to be where, and use the total time on the watch.
I would avoid any use of the auto-lap function in a race, because it can often go off way before you reach the mile of km marker. By doing this, it is going to give you a false sense of where you are at, and you are going to have to do some mathematics to work out how fast or slow you ran the last mile or km.
Using heart rate in a race can be a bit distracting. You might see a number a lot higher than you are used to seeing in training, as you are pushing yourself more than usual. This can often freak people out. I have seen HR used well in marathons and ultra races if you are trying to keep a lid on your effort level for the first part of the run, and make sure you don't start too fast. I'd only do this if you've had a chance to think about and talk this over with a coach beforehand. Some runners can find the chest strap a bit annoying to race with, and the last thing you want is any distractions on race day.
Keep it basic on race day, wear the watch and use it to help you get the time you want. Don't get stressed by it and certainly don't rely on it to 100 pct tell you how far or fast you are going. Although there's only two seconds difference between 3:59:59 and 4:00:01, it makes a huge difference to how you'll view your race result!