Optimal Resistance Training Frequency II

Following up on my last post, here's a new research study that looks at the appropriate frequency for resistance training.  The study is actually a review, and it pools together results from many resistance training studies.

The study looks at muscular hypertrophy in the quadriceps and arm flexors.  For quadriceps, either 2 or 3 days per week yields the exact same increase in muscle, 0.11% per day.  For arm flexors, either 2 or 3 days per week also yields the exact same increase in muscle, 0.18% per day.

From a research perspective, it appears that lifting 2 or 3 days per week produces the same amount of hypertrophy.  All else being equal, it seems that lifting twice per week is the optimal frequency.