There are many factors involved: your fitness level, the types of exercises you perform, total exertion during your workout, stretches (before, during, and after), hydration, rest and nutrition. For some, muscle soreness is cause for concern, while others may believe that they didn’t work out hard enough. In my opinion, muscle soreness should not be used as an indicator of “how good of a workout” you had. Depending on your fitness level, muscle soreness could indicate a great workout OR over-training or the need to stretch more.