Observational Study
Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Psychiatry. May 19, 2023; 13(5): 234-246
Published online May 19, 2023. doi: 10.5498/wjp.v13.i5.234
Associations between Borg’s rating of perceived exertion and changes in urinary organic acid metabolites after outdoor weight-bearing hiking
Pei-Pei Sang, Jin Li, Xu-Dong Tan, Wei Peng, Hong-Hui Zhou, Ya-Ping Tian, Man-Li Zhang
Pei-Pei Sang, Jin Li, Xu-Dong Tan, Wei Peng, Hong-Hui Zhou, Ya-Ping Tian, Man-Li Zhang, Birth Defect Prevention and Control Technology Research Center, Medicine Innovation Research Division, Chinese PLA General Hospital, Beijing 100853, China
Author contributions: Sang PP and Zhang ML designed the study; Sang PP, Li J, Tan XD and Peng W performed the research; Sang PP and Zhou HH analyzed the data; Sang PP wrote the paper; and Tian YP and Zhang ML revised the manuscript for final submission.
Supported by the National Key Research and Development Program of China, No. 2020YFC2004604 and 2020YFC2002700.
Institutional review board statement: The study was reviewed and approved by the Chinese PLA General Hospital Review Board (Approval No. S2021-019-01).
Informed consent statement: All participants signed the informed consent form.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
Data sharing statement: No data were shared.
STROBE statement: The authors have read the STROBE Statement-checklist of items, and the manuscript was prepared and revised according to the STROBE Statement-checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Man-Li Zhang, MD, Associate Chief Physician, Birth Defect Prevention and Control Technology Research Center, Medicine Innovation Research Division, Chinese PLA General Hospital, No. 28 Fuxing Road, Haidian District, Beijing 100853, China. zhangmanli1982@126.com
Received: March 9, 2023
Peer-review started: March 9, 2023
First decision: March 23, 2023
Revised: March 31, 2023
Accepted: April 7, 2023
Article in press: April 7, 2023
Published online: May 19, 2023
ARTICLE HIGHLIGHTS
Research background

The Borg’s rating of perceived exertion (BRPE) scale was widely used to access subjective perception of effort during exercise, but the relationship between BRPE scale and urinary organic acids metabolism has not been studied.

Research motivation

Our article mainly explored the relationship of urinary organic acids metabolism and the BRPE scale during exercise and reflected the psychological perception degree of effort from an objective physiological perspective.

Research objectives

In this work, we aimed to evaluate whether the BRPE scale could be used in the prescription of outdoor hiking with weight-bearing based on urinary organic acids metabolism, which provides an objective physiological data support for the application of BRPE scale in outdoor hiking training.

Research methods

Eighty-nine healthy men participated in this project and underwent 40 km (6 h) training with 20 kg carriages. After the training, they truthfully filled in the BRPE scale and urinary organic acids were detected. We used multidimensional statistical analysis including principal component (PCA) analysis and orthogonal partial least-squares discrimination (OPLS-DA) analysis and heat map analysis to explore the differences in metabolic profiles of organic acids with different BRPE scale. At last, differential metabolites were screened and pathway analysis was performed.

Research results

There were significant statistical differences in urinary organic acids before and after exercise. According to the BRPE scale, individuals were divided into groups of 6-12 scale (easy), 13-16 scale (somewhat hard) and 17-20 scale (very hard). PCA results showed no separation trend among the three groups. Further analysis with OPLS-DA showed that, group of 6-12 scale and 13-16 scale, 6-12 scale and 17-20 scale could be separated obviously, and group of 13-16 scale and 17-20 scale could not be separated, so group of 13-16 scale and 17-20 scale were combined into group 13-20 scale. OPLS-DA results showed that group 6-12 scale and 13-20 scale could be separated. Heat map results also showed significant metabolic differences between group of 6-12 scale and 13-20 scale. According to the standard of a variable importance in the projection > 1, fold change > 1.5 and P < 0.05, 19 different metabolites were screened, which mainly in citrate cycle (tricarboxylic acid cycle) and alanine, aspartate and glucose metabolism.

Research conclusions

Our results showed that the BRPE scale could be used to monitor body fatigue in long-distance outdoor hiking with weight bearing.

Research perspectives

We provide an objective method to evaluate body fatigue in outdoor-hiking exercise.