The repeated bout effect evokes the training-induced skeletal muscle cellular memory

Area of Science:

• Exercise physiology
• Molecular biology
• Sports science

Background:

• Physical exercise is vital for health and chronic disease prevention.
• Exercise acts as a stressor, activating adaptive responses (hormesis).
• Muscle memory influences skeletal muscle's adaptive capacity to stimuli.

Purpose of the Study:

• To explore the molecular mechanisms of the Repeated Bout Effect (RBE).
• To understand how RBE contributes to muscle memory.
• To inform training programs and therapeutic interventions.

Main Methods:

• Review of existing literature on exercise physiology and molecular adaptations.
• Analysis of neural, cellular, and tissue-level responses to exercise stimuli.
• Exploration of extracellular matrix and inflammatory pathway involvement.

Main Results:

• Eccentric exercise triggers adaptive responses in skeletal muscle.
• RBE involves neural adaptations, altered muscle/tendon properties, ECM remodeling, and modulated inflammation.
• These adaptations enhance stress tolerance and reduce subsequent exercise-induced damage.

Conclusions:

• Deciphering RBE mechanisms can optimize training for athletes and active individuals.
• Enhancing muscle memory adaptations may aid recovery in patients with exercise intolerance or post-immobilization.
• Pharmacological or exercise-based interventions targeting RBE show therapeutic potential.