Phosphatidic acid enhances mTOR signaling and resistance exercise induced hypertrophy. Jacob M Wilson et al.
We have previously examined the absorption kinetics of 1.5 g PA and observed an increase in plasma concentration after 30 minutes. PA concentrations appear to plateau between 1 and 3 hours following ingestion while peaking at 3 hours following ingestion. After 7 hours, PA concentrations remained elevated. In addition, LPA demonstrated a bimodal absorption kinetic with plasma concentration peaking at 1 hour, returning to baseline at 2 hours, and peaking again at 3 hours [17]. Thus, exogenous elevations of PA may be provided through oral supplementation, while endogenous production could be fostered through a resistance training stimulus. Theoretically, the combination of the two could result in greater skeletal muscle hypertrophy than resistance training alone.
The PA group received 750 mg of soy-derived PA (Mediator®, Chemi Nutra, White Bear Lake, MN) per day, while the PLA group received 750 mg of rice flour, each delivered in 5 visually identical capsules. On RT days, participants consumed 450 mg of their respective supplement 30 minutes prior to RT and 300 mg immediately following RT with 24 g of hydrolyzed collagen protein powder from beef skin (Peptiplus XB agglomerated, Gelita AG, Eberbach, Germany) mixed with 500 ml water. The protein supplement was provided in order to ensure control for post-exercise meals between groups and hydrolyzed collagen was chosen as an incomplete protein source low in leucine (3.2 weight%). On non-RT days, participants consumed 450 mg of their respective supplement with breakfast and the remaining 300 mg with dinner.