Muscle-specific creatine kinase gene polymorphism and running economy responses to an 18-week 5000-m training...

To investigate the association between muscle-specific creatine kinase (CKMM) gene polymorphism and the effects of endurance training on running economy.

102 biologically unrelated male volunteers from northern China performed a 5000-m running programme, with an intensity of 95-105% ventilatory threshold. The protocol was undertaken three times per week and lasted for 18 weeks. Running economy indexes were determined by making the participants run on a treadmill before and after the protocol, and the A/G polymorphism in the 3' untranslated region of CKMM was detected by polymerase chain reaction-restricted fragment length polymorphism (NcoI restriction enzyme).

Three expected genotypes for CKMM-NcoI (AA, AG and GG) were observed in the participants. After training, all running economy indexes declined markedly. Change in steady-state consumption of oxygen, change in steady-state consumption of oxygen by mean body weight, change in steady-state consumption of oxygen by mean lean body weight and change in ventilatory volume in AG groups were larger than those in AA and GG groups.

The findings indicate that the CKMM gene polymorphism may contribute to individual running economy responses to endurance training.