Mitochondrial Biogenesis and Remodeling Protein Response to Bouts of High-load vs High-volume Resistance Training

Abstract

Introduction: The effects of higher-load (HL; sets of 5 repetitions at 80% of 1-RM) versus higher-volume (HV; sets of 10 repetitions at 60% of 1-RM) resistance training (RT) on various molecular outcomes has proven to be similar between the two paradigms. However, the mitochondrial response to such training paradigms remains understudied. Therefore, the purpose of this study was to interrogate protein level responses of HL vs HV RT in proteins related to mitochondrial biogenesis and remodeling. We hypothesized that HV RT would have a greater effect on mitochondrial markers of biogenesis and remodeling than HL RT. Methods: Fifteen resistance trained males participated in 6 weeks of unilateral RT (single-leg leg press and single-leg leg extension) where each leg was randomly assigned to undergo either the HL or HV RT. Biopsies of the vastus lateralis were collected from both legs at PRE and POST and western blots analysis was used to assess mitochondrial proteins related to biogenesis and remodeling. The data collected were analyzed using two-way within-subject repeated measures ANOVAs. Results: Our results show no statistically significant effect of RT condition on markers of mitochondrial biogenesis and remodeling. However, there was a main effect of time in markers of both mitochondrial biogenesis and remodeling with MFN1 decreasing (p = 0.007, ƞ2 = 0.234) and PINK1 increasing (p = 0.009, ƞ2 = 0.222) from PRE to POST. Conclusion: HL and HV RT paradigms do not differentially affect the mitochondrial markers assessed, and our hypothesis that HV RT would elicit a greater response in markers of mitochondrial biogenesis and remodeling was not supported. However, our data supports the idea that mitochondrial adaptations can be stimulated regardless of the RT paradigm. This discovery could be advantageous for individuals selecting a mode of RT training that is most likely to result in the greatest exercise adherence as well as provide multiple health benefits. Furthermore, research into RT induced mitochondrial adaptations between sexes remains understudied, thus future investigations into these bioenergetic responses is warranted. Funding for assays and participant compensation was provided through discretionary laboratory funds from MR. Additionally, a portion of CG Vann’s effort was funded through the National Institutes of Health (R01AG054840). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.