Hi Gus. I agree with what has been said here. The term “tone” is one of those ambiguous words that our clients often use. By itself, it doesn’t have much meaning, but taken in conjunction with your client’s stated goals, it becomes a bit clearer. Suffice it to say that both forms of resistance training will help develop lean tissue, but as has been stated by others, heavier lifting will work more towards developing muscular strength, whereas the lighter weights and more repetitions will work more towards developing muscular endurance. Again, both will work to build lean tissue. But to answer your direct question about which is BEST for “toning,” a definitive answer can’t really be given absent more information (e.g. what does the person wishing to “tone” mean by that?).