Have you set your activities to private?

If you have then the only person who can see them is you. 
 

You can set activities as private, followers only or public, the latter meaning everyone on Strava can see them if they look. 

​@Petr_H_ZN Just as BryanC noted, the first item to check is your activity privacy control settings. If your activities are all using the “Only You" privacy setting, the activities won’t be visible to anyone except for you. More information about this privacy control can be found here: Activity Privacy Controls

My setting were that my activity see only the followers. But i will try to set all to everyone but thats is missing the point ...why the follower can not see the stats if i had make the choise for the current people i want to see for them my stats...

It’s an ongoing bug since half a year that activities visible only to followers don’t appear in the stats when followers are looking at those. Many others have reported that and it seems that Strava still didn’t fix it.

​@Petr_H_ZN To clarify, your followers should be able to statistics about activities on your Strava account which use the “Followers" privacy setting. Both activities which use the “Everyone" privacy setting as well as activities which use the “Followers" privacy setting should be represented in your Profile statistics when viewed by a follower.

If you find that this is not the case, it would be helpful if you could reach out to our support team with a short description of the issue. If you are able to, including screenshots of what you see and what your friend(s) see when viewing your profile would be quite helpful too.

You can reach out to our support team using the information found here: How Do I Contact Strava Support?