Garmin Running Power - Initial Impressions
I've been using the Garmin Forerunner 645 Music for a few weeks now (I'll review that after I've had more time with it), and thanks to Garmin's new software, Running Power. Here are some of the things I've noticed as I've begun to use Garmin's new running power software:
If you've been using heart rate or pace to train and race by, power is definitely a game-changer. As cyclists know, power gives you an unbiased view of the amount of energy you're using and helps you pinpoint weaknesses and target training zones more efficiently.
Unlike with cycling, the goal isn't always to increase watts. Instead, with running power, what you really want is to use fewer watts for the same pace. This means that you're running form and efficient comes into play big time when training. Whereas cycling power meters typically don't give you much info on your pedal stroke efficiency, just your output.
You can finally quantify your efficiency! It's very helpful to see what small tweaks in your running form do to the number of watts you're using. I've done several easy runs at an 8:00min/mile, when I started using my power meter, the watts were around 350. With a couple small tweaks, I'm now down to about 330 at the same pace. That means I'm using less energy for the same speed!
I haven't raced with it yet, but it seems like pacing for a race isn't quite as straightforward as with cycling power. For example, for a 1/2 Ironman bike, you might stay at 80% FTP. It's pretty easy to simply stay at that number during the bike. But for running power, it's not quite that simple. You really just need to make sure that your goal pace lies in the right power zone depending of the length and intensity of the event. It's not just about staying at some specific intensity factor like with cycling. Instead it becomes about making the most of those watts by being efficient.
You have to slow waaaaay down when you go uphill. Most runners are used to slowing down for uphills, but even going at a very easy pace of ~9:00 uphill, my power quickly jumped into the mid 500s. And you have to go really fast downhills too. It's really interesting to see what effect hills have on you energy output and usage.
I have read that there is a discrepancy between Garmin watt numbers and those of Stryd, or other manufacturers, specifically that Garmin tends to read much higher. All I have to say about that is that I don't think that matters much, unless you're comparing yourself with other athletes who use different devices. When you're training and racing, it doesn't really matter what the numbers are, just that you know what number you need to be at depending on what zone you're working in.
If you plan on using it on a treadmill, I would recommend getting or using an ANT+ foot pod. If you don't, the watch gets it's pace measurement from the chest strap. I found that whenever I held my wrist out to look at the watch, the pace displayed would drop dramatically, like 10min/mile as I was running at a constant pace of 7:30min/mile. My sense is that the watch doesn't really understand what's going on when the watch and chest strap are held at a fixed distance from each other (because your arm isn't swinging as much while you're looking at the watch.) This is important because the watch gets most of its power info from your pace.