Voice Feedback workout alert volume
The voice feedback in the workout app, that reads out the current statistics when running, is extremely quiet, to the point of being unusable. The alert's volume does not seem to be affected by the global slider in the settings app as suggested in this previous post New Voice Feedback workout alert volume i… - Apple Community. The problem only manifests on this one alert in the workout app, the volume elsewhere on the watch is properly reflective of the global volume slider in the settings app. Is there a workout specific volume slider? If not could this potentially be a bug.
Apple Watch Series 8
to decrease the volume or tap the volume up button 
to increase it. You can also tap the slider, then turn the Digital Crown.