Magnetic calcium-regulated mitochondrial sensitivity in adolescents: assessment of skeletal muscle function and body composition

Abstract

BACKGROUND: Magnetic mitochondrial calcium regulation technology, as a non-invasive method for promoting skeletal muscle function, has been effectively demonstrated in improving muscle function and enhancing metabolic sensitivity. Existing studies have shown that this technology has significant physiological promoting effects on adults, the elderly, and postoperative rehabilitation populations, but its intervention effects on skeletal muscle function and body composition in adolescents aged 12-13 years remain unclear. OBJECTIVE: To investigate the sensitivity of skeletal muscle function and body composition to magnetic stimulation in adolescents aged 12-13 years by evaluating these parameters. METHODS: A total of 34 junior high school students from Liaoning Experimental School were recruited and randomly divided into a control group and an experimental group. The control group maintained routine campus activities without a specific physical training program. The experimental group additionally received low-frequency pulsed magnetic field intervention twice a week (stimulation duration 10 min, magnetic field intensity 1.5 mT, frequency 3300 Hz, with an interval of 72 h between interventions) for 4 consecutive weeks. Before (pre-test) and after (post-test) the intervention, changes in maximum strength, explosive power, endurance quality, and body composition indicators of the intervention site were observed. RESULTS AND CONCLUSION: After 4 weeks of 8 sessions of low-frequency pulsed magnetic field stimulation, the participants' explosive power, aerobic endurance, muscle isometric endurance, and body composition indicators were significantly improved, indicating that adolescents aged 12-13 years have good magnetic calcium-regulated stimulation sensitivity for the above skeletal muscle functions and body composition. In terms of maximum strength improvement, the effect was not significant, and their muscle magnetic sensitivity was lower than that of adults, but it had certain advantages in maintaining maximum strength under long-term sedentary conditions. The results indicate that magnetic calcium-regulated mitochondrial technology, as a novel passive, non-invasive skeletal muscle function promotion technique, can be attempted as a new intervention means to improve adolescent physical health.

1. Introduction

Currently, the decline in physical fitness among Chinese adolescents due to lack of physical activity and sedentary behavior has become a focus of societal concern [1]. According to the China Report on Chronic Disease and Nutrition 2020, 86.0% of children and adolescents aged 6-17 years engage in less than 60 minutes of moderate-to-vigorous physical activity per day [2]. Due to limited extracurricular activities, most of the school day is spent in a sedentary state, which is widely recognized as a major cause of various health problems in adolescents, including insufficient muscle strength during growth and abnormal body fat percentage [3], thereby exacerbating the difficulty of preventing and controlling adolescent physical health issues. In the field of sports human science, various active and passive physical health promotion methods have been developed for adolescents. Notably, the use of physical factor-based peripheral passive enhancement techniques to improve physical function has become a research hotspot.

Magnetic calcium-regulated mitochondrial technology, as a non-invasive method for promoting skeletal muscle function, has been effectively demonstrated in improving muscle function and promoting metabolism. Existing research reveals that low-frequency pulsed magnetic stimulation with specific parameters (1.5 mT, 3300 Hz) can activate the classical transient receptor potential channel 1 (TRPC1), thereby triggering a calcium-mitochondrial axis cascade. Magnetic stimulation upregulates intracellular calcium concentration to activate the calcineurin-nuclear factor of activated T cells signaling axis, which serves as a key molecular switch for skeletal muscle adaptive remodeling, specifically upregulating oxidative muscle-related protein expression and mimicking exercise-induced skeletal muscle adaptation and remodeling [4]. Additionally, magnetic stimulation upregulates the transcriptional activity of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), enhancing mitochondrial respiratory chain function. TRPC1-mediated calcium influx not only regulates mitochondrial biogenesis but also forms a bidirectional regulation with reactive oxygen species generation [5], collectively constituting the metabolic adaptation basis of magnetic-sensitive muscle tissue, promoting muscle fiber hyperplasia and injury repair at the tissue level, and enhancing ATP synthesis efficiency at the cellular metabolic level [6], effectively improving the maximum voluntary contraction of skeletal muscle.