If you are not sore, is that a sign that you have recovered properly?

[Lovetogetjacked]

Say a guy lifts and two days later is not sore. Would this be a good indication that he has given his body enough time to recover and can hit those muscle groups again if he wants to?

Overall, is 48 hours enough time to recover usually? Some people claim 72 hours but what is your opinion?

There are guys out there who do not believe in overtraining and hit each muscle group multiple times a week depending on which areas they feel need improvement. Whats your opinion on that philosophy?