At the other extreme of training is the idea, that seems to have primarily developed as steroids started to enter the picture, that a muscle group should be blasted into oblivion once per week and then allowed to rest before training again. Many critics of higher frequency training will point to successful elite (read: drug using) bodybuilders who train that way. Or who at least claim to train that way.
Typically in this approach, one or perhaps two muscle groups would be chosen for a single workout with a fairly large volume of training (often 15-20 sets of 3-4 different exercises) performed for each. Hitting all of the angles, blitzing and bombing were all ideas that came out of this type of approach and generally the body is split across 4 or more workouts which each muscle group getting blasted once every 7 days.
Now, there is no denying that this approach seems to work at the elite level of bodybuilding. However, there are often a lot of other factors involved that people tend to ignore. The main one, of course, is drugs especially steroids (it’s no coincidence that this approach to training developed primarily as steroid use was starting to increase among bodybuilders).
People don’t like to hear it but anabolic steroids will generate muscle growth without training at all and, to a great degree, many elite bodybuilders seem to succeed in spite of their training rather than because of it. In that context, I know of several coaches who work with drug using bodybuilders and invariably growth is better with a higher frequency of training, even in the context of steroid use.
Another factor is that even if top level bodybuilders only hit every bodypart once per week after they have been training for 10 or more years, that’s usually not how they built the majority of their muscle mass (if their reports of what they did earlier in their career are accurate).
Basically, looking at the elite level of any sport and how they train after 15 years of training is usually a losing proposition, what they might be doing at the peak of their career and what they did to get there are often very different things indeed.
But of perhaps more relevance, outside of a small percentage of folks, I simply haven’t seen the majority of natural trainees grow optimally training in this fashion. Basically, it just doesn’t work for the majority in my experience (and in the experience of a lot of coaches I know). Sure, we can always look at the ‘big guys’ in the gym who are doing fine hitting everything once per week but the fact is that the majority of folks training that way aren’t usually growing well at all.