One in five young men has poor semen quality, including low motility. Studying energy metabolism may provide better understanding of sperm motility. We acquired 13C Magnetic Resonance spectra of sperm incubated with 13C-glucose with different concentrations of inhibitors: malonate, oxaloacetate, succinate, and 2-deoxy-D-glucose. This study examined the effect of these inhibitors on sperm lactate production and vitality, with a secondary aim to observe Krebs cycle intermediates in the MR spectrum. Glucose signal significantly decreased with increasing oxaloacetate concentration. Malonate and oxaloacetate and 2DG significantly decreased in lactate production. These inhibitors did not lead to observable 13C labelled Krebs cycle intermediates.