Modulating exercise-induced hormesis: Does less equal more?

Area of Science:

• Exercise physiology
• Cellular adaptation
• Stress response

Background:

• Hormesis describes how low-level stress enhances cellular and molecular pathways for greater stress resilience.
• Exercise induces adaptations through various stressors like thermal, metabolic, hypoxic, oxidative, and mechanical stress.
• These stressors activate signaling pathways regulating gene expression and adaptive responses.

Purpose of the Study:

• To review and integrate knowledge on exercise adaptation mechanisms.
• To critically evaluate interventions targeting these mechanisms within the hormesis framework.
• To assess the impact of interventions on exercise-induced adaptations.

Main Methods:

• Literature review combining and integrating knowledge on exercise adaptation.
• Critical evaluation of interventions based on hormesis principles.
• Analysis of biochemical/molecular effects versus functional/performance outcomes.

Main Results:

• Historically, interventions like antioxidant supplements aimed to reduce exercise-induced stress.
• Reactive oxygen species and inflammatory mediators are crucial signaling molecules for muscle adaptation.
• Some interventions (e.g., carbohydrate restriction, blood flow restriction) may enhance exercise adaptations.

Conclusions:

• Current evidence is insufficient to confirm dose-dependent effects of interventions on muscle adaptation.
• There is a dissociation between biochemical/molecular effects and functional outcomes of some treatments.
• Further research is needed to determine if interventions complement or negate each other and their impact on exercise adaptations.