This question already has an answer here:
When using these two features in LR4 for global adjustments, I normally start with noise reduction and keep sliding till the "pixels" are removed. I then increase sharpening to the point right before artifacts start appearing.
Does this procedure make sense to reduce noise and keep sharpness of the image? Do I need to perform this procedure even if ISO is 100?
NOTE: I'm referring to global adjustments. Thus, the question is not related to local adjustments, i.e., brushes.