The order of concurrent training affects mTOR signaling but not mitochondrial biogenesis in mouse skeletal muscle.

Takanaga Shirai,Kohei Takeda,Yuki Aoki,Tohru Takemasa

doi:10.14814/phy2.14411

Abstract

Concurrent training involves a combination of two different modes of training. In this study, we conducted an experiment by combining resistance and endurance training. The purpose of this study was to investigate the influence of the order of concurrent training on signal molecules in skeletal muscle. The phosphorylation levels of p70 S6 kinase, S6 ribosomal protein, and 4E‐binding protein 1, which are related to hypertrophy signaling, increased significantly in the resistance–endurance order group as compared with in control group not the endurance–resistance order group. The gene expressions related to metabolism were not changed by the order of concurrent training. The mitochondrial respiratory chain complex was evaluated by western blot. Although both groups of concurrent training showed a significant increase in MTCO1, UQCRC2, and ATP5A protein levels, we could not detect a difference based on the order of concurrent training. In conclusion, a concurrent training approach involving resistance training before endurance training on the same day is an effective way to activate both mTOR signaling and mitochondria biogenesis.

Highlights

In many sports, athletes aim to output their maximum performance during competitions or games
Previous study has suggested that concurrent training with resistance and endurance training better suppressed muscle hypertrophy in comparison with resistance training alone (Hickson, 1980; Kraemer et al, 1995)
We hypothesized that the effects of resistance and endurance training can be effectively obtained by changing the order of concurrent training

Summary

| INTRODUCTION

Athletes aim to output their maximum performance during competitions or games. Previous studies have elucidated the differences in training methods and found that each of them can improve either strength, endurance, or both of them. One is resistance exercises like weightlifting or powerlifting that cause skeletal muscle hypertrophy and strength improvements (Ogasawara, Kobayashi, et al, 2013; Ogasawara, Yasuda, Sakamaki, Ozaki, & Abe, 2011). According to previous research that compared concurrent exercise and resistance exercise alone, it was found that the total level of p70S6K in concurrent exercise is lower than that of resistance exercise alone (Apro, Wang, Ponten, Blomstrand, & Sahlin, 2013) The reason for this is the interference effect that occurs between resistance and endurance exercise. In this study, we sought to clarify the difference in the order to concurrent training on skeletal muscle, focusing on mTOR, and mitochondria biogenesis signals

| MATERIALS AND METHODS

| Training methods

| RESULTS

Findings

| DISCUSSION