Apple has officially confirmed that Fitness+ will be available to non-Apple Watch users. Any iPhone updated to iOS 16 will work with it.
This is true for the 21 countries where Fitness+ is currently available. Russia is among them. The service will continue to operate on a subscription basis.
Fitness+ promises regular weekly updates with new workouts, as well as all the various rewards for meeting goals. It will be possible to install the application on the iPhone with the release of the latest version of iOS from September 12th.