There are many things about that study worthy of comment, and which are cause for questioning its conclusions. I don't have time to go into this in great detail, but here are a few points worth considering, IMHO:Changes in exercises are more effective than in loading schemes to improve muscle strength. Changes in exercises are more effective than in loading schemes to improve muscle strength. - PubMed - NCBI
1. The study used Cybex Smith machine squat 1RM as its baseline. From the full article, which may be viewed here:
Changes in Exercises Are More Effective Than in Loading... : The Journal of Strength & Conditioning Research
"the squat exercise 1RM load was assessed on a conventional Smith machine (Cybex)."
This is not a metric I consider valid as an indicator of "strength" - the article concludes that certain things produce, "strength gains" better or worse than other things, but do we really care that a Smith machine squat improved?
The subjects were
2. "Seventy physically active males volunteered for this study. ... They were not engaged in any form of regular ST [Strength Training] for at least 6 months before the study ..."
I don't know how they were physically active if they weren't strength training, but I don't think this description applies to most of us here, nor do I think it applies to the readers of our forum, who are generally engaged in regular strength training. It doesn't make qualify them as experienced strength trainees, and results for novices are, at least to me, not terribly interesting since we know that novices benefit from most safe strength training protocols.
3. Look at the training protocols used by the Variable Intensity, Constant Exercise group shows things like sets of 2 with a 10RM weight. I don't know what that might do for someone, but I don't think it will make them much stronger.
In conclusion, I hope everyone will read every study they find of interest from beginning to end before determining the applicability of its conclusions for their own training.
-S-