Variability in training-induced skeletal muscle adaptation.

Area of Science:

• Exercise physiology
• Molecular biology
• Human genetics

Background:

• Physiological adaptations to exercise training in human skeletal muscle are unpredictable.
• The molecular basis for heterogeneous responses to exercise is increasingly understood.
• Individual differences in exercise adaptation have significant medical implications.

Purpose of the Study:

• To review recent advancements linking genetic variability and gene expression to exercise adaptation.
• To explore the concept of muscle "adaptability" as a general trait.
• To discuss factors limiting physiological adaptation to exercise in humans.

Main Methods:

• Review of current literature on genetics, transcriptomics, and exercise adaptation.
• Analysis of studies investigating molecular mechanisms of muscle plasticity.
• Discussion of human studies on aerobic capacity, endurance performance, and muscle hypertrophy.

Main Results:

• Genetic and transcript abundance variability are linked to individual differences in aerobic capacity, endurance, and hypertrophy.
• Certain gene networks may determine general muscle adaptability irrespective of the training stimulus.
• Understanding heterogeneity aids in dissecting genetic and environmental factors limiting adaptation.

Conclusions:

• Individual responses to exercise training are highly variable due to genetic and molecular factors.
• Investigating this heterogeneity provides a unique human model to study adaptation limits.
• Future research should focus on identifying specific gene networks and environmental influences on muscle adaptability.