How it Works
This automatic feature detects if you recorded an activity at the same time as other users on the same route. When a group activity is detected, your activity becomes linked to any matching activities. On your Feed, the group activity is displayed with one map and a list of the group members you follow below. When viewing an activity details page, you will be able to view the full list of athletes matched in the group. In order to be detected as a group activity, our algorithm considers the percentage of elapsed time in your activity that the other activity is 'nearby.' If the other activity is nearby for more than 30% of the time, it is considered a match. This threshold allows for other users to join a group ride or run mid-way through, or leave early as long as they match the set percentage.
- The algorithm is asymmetric. For example, if you join someone for the last 5 miles of their 50-mile ride, it will say that you rode with them, but not that they rode with you. In most cases, however, matching is symmetric.
- The algorithm is activity type agnostic (for example ski can be matched with snowboard).
- 'Nearby' means closer than a few hundred meters together. However, this rule is more flexible for longer distance activities.
Leaving a Group
If you are having trouble matching to your group activities and you are a Strava mobile App user, check your device's internal clock settings. If you set your phone's clock manually, your set time could be over 1 minute off from the automatic clock from cell towers/satellites causing you to miss the group activity detection. Instead, try setting your clock to update automatically.