Effects Of High-Load Versus High-Volume Resistance Training On Muscle Sarcoplasmic, Actin, And Myosin Protein Concentrations

Abstract

PURPOSE: Our laboratory has recently shown high-volume resistance training (RT) can elicit increases in skeletal muscle sarcoplasmic protein concentrations, while also causing a dilution of contractile protein concentrations (i.e., sarcoplasmic hypertrophy). The purpose of this study was to evaluate effects of 6 weeks of high-load (HL) and high-volume (HV) training on skeletal muscle sarcoplasmic and contractile protein concentrations. METHODS: Trained college-aged males (n = 15; training age = 7 ± 3 yrs; mean 1RM squat relative to bodyweight = 1.9 ± 0.4 kg) performed 6 weeks of unilateral lower-body RT, with one leg performing HV training and the contralateral leg performing HL training using leg press and leg extension. Participants underwent a period of passive recovery lasting 10 days following the training intervention. Vastus lateralis biopsies were obtained from both legs prior to the start of training (PRE), 72 hours following the last training day (POST), and 1 week following POST testing (POSTPR). Sarcoplasmic protein content was determined following differential centrifugation using bicinchoninic assays, and actin and myosin concentrations were quantified using SDS-PAGE and Coomassie staining. RESULTS: Significant main effects of time (p = 0.022) and condition (p=0.002) were observed and condition by time approached significance for sarcoplasmic protein concentrations (p = 0.088). There were no significant interactions or main effects for actin or myosin concentrations. CONCLUSIONS: Contrary to our prior data, sarcoplasmic, actin and myosin concentrations remained unaffected with HV training. However, interesting trends were observed for sarcoplasmic protein concentrations and these will be further interogated.