Just like AAS and GH usage, the best lifting protocol is highly individualistic. For my body, "heavy duty" once per week Mentzer type training always gave me the best gains, until age caused me to back down from the heavy weights due to injury prevention. Even prior, however, certain muscle groups such as biceps saw better results on more frequent, lower weight, higher volume training. There is no "one size fits all" when it cones to training optimization - this is why there is so much debate. Find what works for YOU!Science seems to say train everything twice with high volume but big guys seem to train them once.
What's the deal here is twice better for novice trainers maybe and once for more experienced guys?