Recording with the Strava Mobile App
The following activity types can be recorded with the Strava mobile app: CrossFit, elliptical, stair stepper, weight training, yoga, and workout. During the recording, you’ll be able to see the activity start time, elapsed time, and your heart rate if you’ve paired a heart rate monitor.
On the mobile app, is it not currently possible to record indoor runs, indoor rides, or measure distance using a pedometer or other sensors. However, you can record indoor runs with the Strava Apple Watch App using your watch’s pedometer to measure distance.
Recording with a Third-Party App or Device
Indoor activities can be recorded with any Strava-compatible GPS device or non-GPS device as long as the data is compatible with the Strava uploader (or can be synced from another app to Strava). If you record indoors especially with sensors for speed, cadence, or power, you should disable the GPS on your device while recording a stationary activity. This will help with correct the analysis of your data such as distance and speed.
The Indoor/Stationary Activity Page
The stationary activity page will not display a map. Instead, the performance graph is highlighted to give you a view of your heart rate, speed, cadence, or power data if available. If you don't have any accessory data, then there may not be a performance graph but you will still get credit for your elapsed time.