Mots-c Plasma Levels Following A Single Session Of MICT And HIIT

Abstract

Acute moderate intensity continuous training (MICT) and high-intensity interval training (HIIT) result in increased mitochondrial transcriptional activity. The mitochondrial open reading frame of the 12S rRNA-c (MOTs-C) is a peptide encoded from mitochondrial DNA. This mitochondrial derived peptide can regulate skeletal muscle glucose uptake and fatty acid beta-oxidation. However, it is not known if MOTs-C concentrations are altered following an acute bout of MICT or HIIT. PURPOSE: The present study investigated the effects of acute MICT and HIIT on MOTs-C levels in plasma pre- and 3 hours post-exercise. METHODS: Ten recreationally active (>150 min moderate-vigorous intensity aerobic activity per week ≥ 1 year) males (n=5; age 25.2 ± 1.1, VO2max 48.0 ± 4.9 ml/kg/min) and females (n=5; age 21.6 ± 3.6, VO2max 39.4 ± 7.7 ml/kg/min) were conveniently recruited for an initial study conducted at the UNM Exercise Physiology Laboratories. The original study, and the current expanded exploration were approved by the institution’s Institutional Review Board (IRB). Participants completed a health history, and physical activity history questionnaire. Based on criteria from the American College of Sports Medicine, all participants were considered low-risk. Utilizing a crossover design subjects performed an acute bout of MICT and HIIT exercise on a treadmill. The MICT bout consisted of 60 minutes at 55% of maximum velocity (Vmax) achieved during the VO2max test and the HIIT trial required two sets of 6 x 1-min bouts at 100% Vmax, with 5 minutes recovery at 3 MPH between sets. Trials were conducted at least 72 hours apart in randomized order and in a fasted state. Plasma samples were collected during a previously conducted study and frozen for future analysis. MOTs-C was measured from the previously collected samples obtained pre- and 3 hours post-exercise using an enzyme-linked immunosorbent assay. RESULTS: There were no significant changes in plasma MOTs-C (p = 0.21) from pre to post-exercise for MICT (220.4 ± 62.9 vs 248.4 ± 45.2 ng/ml, respectively) or HIIT (p = 0.38) (227.9 ± 62.4 vs 246.9 ± 75.9 ng/ml, respectively). CONCLUSION: Our findings show plasma MOTs-C does not increase in response to a single session of MICT or HIIT.