Pause your workout and tap the Music icon as shown below.

After that, please follow these steps:
1. Select your preferred music app (Spotify or YouTube Music).
2. Select the song you want to listen to.
3. Open the Muscle Booster app and continue training.
Pause your workout and tap the Music icon as shown below.

After that, please follow these steps:
1. Select your preferred music app (Spotify, Apple Music, or YouTube Music).
2. Select the song you want to listen to.
3. Open the Muscle Booster app and continue training.