Abstract
The purpose of this study was to examine the effects of neuromuscular electrical stimulation training for 12 weeks on the abdominal muscle size in trained athletes. Male collegiate track and field athletes participated in the present study and were randomly allocated to either training or control groups. Eleven participants of the training group completed a 60-session training program over a 12-week period (23 min/session, 5 days/week) involving neuromuscular electrical stimulation (mostly 20 Hz) for the abdominal muscles in addition to their usual training for the own events. The participants of the control group (n = 13) continued their usual training. Before and after the intervention period, cross-sectional areas of the rectus abdominis and abdominal oblique muscles (the internal and external obliques and transversus abdominis) and subcutaneous fat thickness were measured with magnetic resonance and ultrasound imaging. There were no significant changes in cross-sectional area of the rectus abdominis or abdominal oblique muscles or in subcutaneous fat thickness in the training or control groups after the intervention period. The change in cross-sectional area of the rectus abdominis in each participant was not significantly correlated with pre-training cross-sectional area and neither was the mean value of fat thickness at pre- and post-training. These results suggest that low-frequency (20 Hz) neuromuscular electrical stimulation training for 12 weeks is ineffective in inducing hypertrophy of the abdominal muscles in trained athletes, even when they have a thin layer of subcutaneous fat.
Citation: Wakahara T, Shiraogawa A (2019) Effects of neuromuscular electrical stimulation training on muscle size in collegiate track and field athletes. PLoS ONE 14(11):
e0224881.
https://doi.org/10.1371/journal.pone.0224881
Editor: Nir Eynon, Victoria University, AUSTRALIA
Received: July 26, 2019; Accepted: October 23, 2019; Published: November 13, 2019
Copyright: © 2019 Wakahara, Shiraogawa. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: All relevant data are within the manuscript and its Supporting Information files.
Funding: This study received funding from MTG Co., Ltd. (https://www.mtg.gr.jp/en/) to TW. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: I have read the journal's policy and the authors of this manuscript have the following competing interests: This study received funding from MTG Co., Ltd., which made the NMES device used in the present study. However, the authors do not have any personal relationships or competing interests to the funder. This does not alter our adherence to PLOS ONE policies on sharing data and materials.