Skeletal Muscle Adaptations to Peptide-Supplemented Resistance Exercise Training

Skeletal muscle plays an important role in maintaining human health and well‐being,allowing movement and exercise, blood sugar regulation, providing protection from falls,and facilitating tasks of daily living. Strengthening the musculoskeletal system throughchronic resistance exercise training can extend both life span and quality of life.Significant research has been dedicated to understanding the anabolic processes whichfacilitate muscle growth and strength gains during chronic resistance exercise training.It is well known that dietary protein supplementation can enhance the amount of musclestrength and size that is gained by healthy adults across ≥6 weeks of resistancetraining. These effects are attributed to the increased availability of amino acids whichstimulate and support resistance exercise‐induced muscle growth. The amino acid leucineplays a key role in initiating the growth of muscle proteins and is abundantly foundwithin animal‐based proteins. In recent years, there has been an increase in othercommercially available dietary supplements with purported anabolic effects. These includethe leucine metabolite β‐hydroxy‐β‐methylbutyrate (HMB), the peptide dileucine comprisingtwo chemically bonded leucine molecules, and peptides found to be abundant in the Fava(Broad) bean (PeptiStrong®). However, whilst there is some evidence which suggests thatthese supplements can enhance skeletal muscle protein synthesis when consumed inisolation, the combined impact of consuming these compounds on long term muscle growthand resistance training adaptation in young healthy individuals remains to beinvestigated.Previous studies have shown that consuming Dileucine or PeptiStrong® can furtherstimulate the acute muscle protein synthesis response compared to more traditionalsupplements such as Leucine and whey protein. In addition, HMB supplementation in oldermales has been shown to promote thigh‐lean mass gain during lower‐limb resistancetraining. The impact of these supplements on post‐resistance exercise muscle synthesisrates in younger individuals have yet to be evaluated, although, it is possible that acombined dietary supplement could enhance post‐exercise muscle anabolism which, over aperiod of repeated resistance exercise bouts, may induce greater skeletal muscle mass andstrength gains. In addition, whether supplementation with these compounds is able toregulate cellular processes which underpin changes in both muscle protein synthesis andbreakdown has also not been established.This project primarily aims to determine whether an innovative bioactive peptidesupplement can enhance skeletal muscle adaptations to 8‐weeks of resistance training inhealthy, young, untrained individuals when compared to a placebo. In addition, this studyaims to investigate whether long term resistance exercise training alters human skeletalmuscle autophagic flux by utilising a novel ex‐vivo autophagic flux assay.