The authors studied muscle protein synthesis (MPS) and muscle protein breakdown (MPB) in young males supplemented with CaHMB.  Similar to their previous study with HMB free acid, CaHMB provided a comparable stimulation of MPS and suppression of MPB. The pro-anabolic properties of CaHMB were shown to include activation of mTORc1.  Therefore, both CaHMB and HMB free acid have similar effects on muscle protein turnover despite the differences reported in bioavailability.