Growth factors play crucial roles in the synthesis of muscle tissue. One growth factor, in particular, Insulin-like growth factor-1 (IGF-1), is of great importance to athletes as it is involved in the expression of a complete spectrum of muscle-specific proteins. Scientists have known for a 
while that IGF-1 production is directly correlated to nitrogen balance. And the production of this growth factor is also thought to be closely related to the quality and quantity of your protein intake. Now, the results of a recent study have confirmed this.
Studies show that protein supplementation can increase your body’s IGF-1 production. A recent study revealed that consistent, high-quality protein supplementation combined with intense weight and cardio training increases circulating IGF-1 concentrations where those that followed the same training protocol but didn’t supplement had decreased levels of IGF-1. This particular study was over a 6 month period. So this is long-term IGF-1 elevation.
The results of this six-month investigation show that protein quality and quantity have a profound influence on circulating IGF-1 levels during intense training. VP2 Whey Isolate delivers the most effective isolated and hydrolyzed oligopeptide fractions scientifically proven to build more lean muscle mass than other proteins. It’s also shown in scientific studies to increase muscle fiber size directly.
It’s clear through the research that VP2 triggers muscle growth through multiple pathways, but as research continues, the VP2 and IGF-1 connection is becoming more evident.
This study identifies yet another important role of specific protein supplementation for people who want the best results from intense exercise training.
Source: Am J Clin Nutr 81: 1442-1448, 2005.
