In this study the researchers looked at the endocrine response after an acute heavy resistance exercise protocol.  Twenty resistance-trained subjects were randomized to receive either 1 gram of HMB free acid or a placebo 30 minutes before the exercise bout.  Endocrine responses from pre- to 30 min post exercise were measured. The researchers observed that both growth hormone (GH) and insulin like growth factor-1 (IGF-1) area under the curve were increased with the HMB free acid in comparison to the placebo group.  These findings further demonstrate how HMB supplementation potentiates and increases the anabolic response of resistance exercise.