Strangely enough, Apple Fitness+ hasn't been available on the Mac. Until now, that is. With macOS Monterey, Mac machines can support content via AirPlay from Apple devices like the iPhone or iPad, including Apple Fitness+ videos. So, now you can start a workout from your mobile device and then wireless stream the video to your laptop. A big drawback is you don't have access to on-screen metrics like heart rate and calories burned. You can only see this data on your Apple Watch.
According to MacRumors, AirPlay to Mac is supported on the following Mac models running macOS Monterey: