Is posible make virtual races in my website using the strava api?

Can you provide more details? There isn't enough information in your post to give you any kind of answer.

• Are you using webhooks?
  • Are you seeing new activities come in on your webhook?
• Are you receiving an error from the API when you make a call?
  • If so what error?
  • What endpoint are you trying to access?
  • Are you using valid access tokens for the athlete? Tokens expire after some time and need to be refreshed. You should have received a refresh token when the athlete authorized your app.

Generally, yes the API can be used to do what you've described. When a new activity comes in to your webhook, you can make an API call to getActivityById to get details of the activity including the distance.

I also had the same question about whether the Strava API can be used to build a virtual race system where participants connect their accounts, their activities are checked against a required distance, and medals or other rewards are issued after they complete the challenge. The overall concept seems very useful, but I’m also a little confused about the current API permissions and what data an application is actually allowed to retrieve. If the client_id suddenly stopped being allowed to obtain the activity data, I’d be interested to know whether this is related to the app configuration, authentication scopes, API restrictions, or a recent change in Strava’s developer requirements.

I’d also appreciate clarification from someone who has implemented something similar. In particular, it would be helpful to understand whether a virtual race can officially be built around Strava activity data, what permissions need to be requested from participants, and whether there are restrictions on automatically determining who completed a distance and then providing a medal. If the POST request is now being rejected, knowing the exact response code and error message would probably help narrow down the cause. Hopefully someone familiar with the Strava API can confirm the supported approach and explain whether the existing application needs to be reconfigured or approved differently.