Studying energy metabolism in sperm may be helpful in understanding the relationship between motility and infertility. To understand sperm metabolism, we acquired 13C MR spectra during incubation with 13C-glucose in a normal and hypoxic atmosphere. Studies suggested that glycolysis is the main pathway for energy metabolism in sperm but whether glycolysis or oxidative phosphorylation(OXPHOS) dominates varies among species. This study examined the effect of hypoxia on sperm energy metabolism, with a secondary aim to observe Krebs cycle intermediates in the MR spectrum. Lactate signal in the hypoxia group was significantly higher than in the normoxia group. No Krebs cycle intermediate was detected.