Quote (RyanTBS25 @ Dec 11 2013 08:55pm)
Are there studies that show the benefits of utilizing the heightened protein synthesis levels by working out muscles twice a week? Or are you really missing out on that much by only training a muscle every 5-7 days instead of every 3-4 days?
This is a topic of great debate. However, in my time of studying, training, and researching, I've found that this question is answered primarily by genetics.
Some people will respond extremely well to increased volume of training per muscle group, per week. IE: training chest/bis 3x per week sees exponentially larger gains than 1x per week.
Other individuals will see a loss of strength and size from doing this.
Obviously, eating/sleeping, supplementation, and other factors play a role besides genetics. However, two evenly matched subjects, with different genetics, will see different results from the same plan.
The best bet here is to try different things and see how your body responds. A good rule of thumb, however, is that the body requires at least 24-48 hours to FULLY repair itself after muscle tearing achieved from a proper workout (hypertrophy or strength).