The Forerunner 255 and 955 are the first two Garmin watches that can track running power natively (that is, without the need for an additional app). If you're not familiar with the term 'running power', it simply means the amount of effort you've exerted during a run, normalized to take account of factors like gradient, wind, and altitude. It's a useful tool that makes it easier to compare totally different runs like-for-like.
Its addition to the two new Forerunners sounded great at first, but when you look a little closer, it's perhaps not quite the revelation it first appeared to be.
There's been an official Running Power app available to download through the Garmin Connect IQ store since 2017, though it has real limitations. The data isn't fully integrated with Garmin Connect, and although it's visible through a sub-menu in the app, it doesn't link nicely with your other run data.
Native running power for the Garmin Forerunner 955 and 255 works in a very similar way, but now the whole experience is much smoother and blends in seamlessly. You can now set power zones for training (which work in the same way as heart rate zones), for example, and there are workouts based on running power zones.
Power to the people
However, there are still drawbacks. Whether you're using an older watch with the Connct IQ app or one of the two new Forerunners with native running power, you'll also need either a Garmin HRM-Pro or a Garmin Running Dynamics Pod, which will gather data including vertical oscillation, ground contact time, and stride length using the position of your body.
Those stats should be more accurate than similar figures gathered from your wrist, but the need for an extra device means there's an additional cost on top of the price of the watch itself. That's a tough sell when so many other watchmakers are calculating running power using data from the wrist alone.
We've recently tested the Polar Pacer Pro and Coros Vertix 2, both of which have their own ways of calculating running power without any additional sensor, and now Apple has announced that the same feature will be coming to the Apple Watch later this year.
It would be tough to compare the power metrics from Garmin, Polar, Coros, and Apple to determine which is the most accurate – particularly since none of them account for all the factors that can affect running power, and all use a combination of accelerometers and gyroscopes to estimate values.
That's something of a moot point, though. What really matters aren't the specific numbers, but the trends – and if it's possible to estimate those using data from the wrist alone, that might be a preferable choice for many people who've already spent hundreds of dollars on the best GPS watch they could afford.
I'm not suggesting Garmin should abandon its current means of calculating running power, but an option to take power measurement from the wrist alone would be a valuable tool for people who own a new Forerunner, but don't currently have a HRM-Pro or Running Dynamics Pod (with the caveat that it's less accurate). I'm not too optimistic, but I've got my fingers loosely crossed for those of us whose budgets don't extend to additional trackers.
