Abstract:Objective To study the relationship between single nucleotide polymorphism (A79G) and (T109C) in the second exon of the myoglobin gene and exercise-induced muscle damage. Methods Eighty-five soldiers of CAPF performed a strenuous weight-loading exercise and the time course of serum creatine kinase (CK) activity was measured. Myoglobin gene polymorphism was detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Association between resting CK (CKpre), maximal CK (CKpeak), maxiaml changes in CK (△CK) and gene polymorphism was then analysed. Results The activity of CK [CKpre: (145±33) U/L] gradually increased at 24 h after strenuous exercise and reached peak value at 72 h[CKpeak: (2972±1648) U/L], which then slowly reduced, but still higher than rest level at 120 h. The genotype frequencies (AA=54.1%, AG=40.0%, GG=5.9%) and allele frequencies (A=74.1%, G=25.9%) were coincident with Hardy-Weinberg equilibrium. Compared between groups, CKpre, CKpeak and △CK in (AG+GG)-group were all higher than those in AA genotype group (all P<0.01). Conclusions The single nucleotide polymorphism (A79G) in the second exon of the myoglobin gene might contribute to susceptivity of exercise-induced muscle damage. Subjects with G allele have increased risk for developing muscle damage, whereas AA genotype may have protective effects.