Journal Article Ahead of print
PubMed: 42691477 DOI: 10.1152/ajpcell.00795.2025
High-intensity interval training via electrical stimulation enhances endurance by preserving sarcoplasmic reticulum Ca 2+ transients in mouse skeletal muscle.
Am J Physiol Cell Physiol
Authors: Luke D Flewwelling, Masih Jafari, Shahrzad Khajehzadehshoushtar, Takashi Yamada, Christopher G R Perry, Arthur J Cheng
Affiliations
- Muscle Health Research Centre, School of Kinesiology & Health Science, Faculty of Health, York University, Toronto, ON, Canada.
- Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Abstract
This study investigated the effects of high/low-intensity interval training (HIIT/LIIT) via electrical stimulation (ES) on muscle performance, specifically focusing on fatigue resistance and cytoplasmic free calcium ([Ca 2+]i) dynamics in mouse skeletal muscle. Thirty 9-week-old female C57BL6 mice underwent four weeks of involuntary IT-ES in hindlimb plantar flexor muscles in vivo, with stimulation frequencies set at either 20 Hz (LIIT) or 100 Hz (HIIT). Our results showed that IT-ES significantly enhanced fatigue resistance, particularly with HIIT, evidenced by improved muscle torque output and better preservation of tetanic [Ca 2+]i levels during repeated contractions. Additionally, IT-ES led to increases in sarcoplasmic reticulum (SR) Ca 2+ handling proteins, such as SR Ca 2+ ATPase 1 (SERCA1) and the ryanodine receptor 1 (RyR1), as well as mitochondrial respiratory complex proteins, indicating enhanced metabolic adaptations. The results suggest that HIIT-ES is an effective intervention for improving muscle function, intracellular Ca 2+ management, and mitochondrial content, providing a foundation for future consideration in rehabilitation and clinical settings.
MeSH
Cell Physiological Phenomena, Sarcoplasmic Reticulum, Muscles, Fatigue, Calcium, Muscle, Skeletal, High-Intensity Interval Training