Muscle genetic variants and relationship with performance and trainability

Area of Science:

• Human genetics
• Exercise physiology
• Biochemistry

Background:

• Genetic variations in muscle enzymes can influence physiological responses.
• Muscle creatine kinase (CKM) and adenylate kinase (AK1M) are key enzymes in energy metabolism.
• Understanding enzyme variants may reveal insights into individual performance differences.

Purpose of the Study:

• To investigate the prevalence of CKM and AK1M genetic variants in a human population.
• To compare the performance and trainability of individuals with CKM/AK1M variants versus controls.
• To assess the functional significance of these enzyme polymorphisms.

Main Methods:

• Protein fractionation using thin-layer isoelectric focusing on vastus lateralis muscle samples.
• Identification and frequency calculation of CKM and AK1M variants.
• Performance testing and exercise training response comparison between variant and control groups.

Main Results:

• Six individuals (1% frequency) exhibited a novel CKM variant; 21 individuals (3.5% allele frequency) were heterozygotes for an AK1M variant.
• No significant differences in performance indicators were observed between variant and control groups.
• CKM variant subjects showed trends towards higher effectiveness in a 90-min test and less force decline over 60 seconds.

Conclusions:

• Allelic variation in CKM and AK1M genes, while not significantly impacting overall performance, may hold functional significance.
• Observed trends suggest potential subtle influences of these enzyme variants on muscle function and endurance.
• Human performance and trainability are multifactorial, not solely determined by these specific enzyme polymorphisms.