One of the most common questions asked by new Zwift runners is, “Do I need a watch to run on Zwift?” The short answer is simply: no. However, this deserves some further explanation.
As long as you have the Zwift app on your phone, tablet, or computer and you have a way to get your speed on the treadmill into the app (a ‘speed source’), then you’re good to go.
Your activity will automatically upload directly from the Zwift app to Strava or Garmin Connect after you have finished. No watch required.
There are only two ways you might use your watch in Zwift. The first is to broadcast heart rate. Many running watches have an optical heart rate sensor on the back and some allow you to rebroadcast your heart rate.
Unfortunately, most watches use a protocol called ANT+ to rebroadcast your HR and therefore it can’t be picked up by your Bluetooth-only phone or tablet. But with an ANT+ USB stick you can get the ANT+ signal into your computer. So if you run Zwift on a computer and you have a watch that can broadcast HR, then there’s no need to wear a chest strap.
Connecting a heart rate monitor to Zwift is by no means mandatory, though. You can still use Zwift perfectly well without pairing HR!
The other way you might use a running watch with Zwift is if you own a Garmin 245, 945, or one of the Fenix 6 range. These watches feature a profile called Virtual Run.
This is extremely handy because it allows the rebroadcast not only of heart rate, but of speed and cadence from the watch to Zwift. Furthermore, it rebroadcasts in Bluetooth rather than ANT+ which means it can connect to the Zwift app running on any device.
In addition, there are some who like to record their run on the watch as well as Zwift, and the Virtual Run profile allows us to do that using the same sensors for both. This maintains consistency of data between both the Zwift and watch activities.
If you don’t have any of the standard speed sources listed above, but you do own a Garmin 245, 945, or Fenix 6, then your watch is the one and only thing you need to run on Zwift.
Because your watch contains an accelerometer, it can do an adequate job of measuring your speed when running on a treadmill. Using the Virtual Run profile and rebroadcasting this and your HR to Zwift means there’s no need for any other equipment.
So there is no need to use your watch to run on Zwift. However, there are some instances where using it can be useful and some situations where it may be your only option.