Q: Research shows that a single set of 12 repetitions with the proper weight can build muscle just as efficiently as three sets of the same exercise.What is your view? How can doing 3 times the work not produce better results? It does not make sense.

A: The findings of those studies are being quoted too liberally. The studies in question were looking at the progress made by absolute beginners who have never weight trained.. For them, indeed, single- and multi-set programs returned similar results, though I believe even in their case, multi-set programs produced greater strength gains. However the most important point is that once you start looking past the absolute beginners and to intermediate weightlifters, there's absolutely no question that multi-set programs on average produced greater gains in strength and greater desired changes in body composition.

That is not to slam single-set training entirely. It has its place in a well-designed periodized program. Single-set phase can be used for 'peaking' -- when one is training with 1-2 rep sets and lifting maximum weights. It can also be used as a break to prevent overtraining after a partilarly intense high-volume training phase. Finally, some people really do respond to very low-volume training better. It's a job of a good personal trainer to identify such a tendency in the trainee.

But on the whole, there's incontrovertible evidence that multi-set training on average produces greater results. Just keep in mind that more is not always better either: while 100 total heavy sets/week may give you good results it's quite likely that 200 sets/week will not only not give you good result but lead to overtraining, negative results, and injuries. Once again, a good trainer knows how to put together a good year-round program for the trainee to prevent both undertraining and overtraining and to keep them on pace for maximum results.