To investigate the acute effects of short and long durations of plank exercise training on the endothelial function (flowmediated dilatation, FMD), shear rate, blood flow, vascular resistance, heart rate and arterial blood pressure. Thirty-two healthy untrained (inactive) male participants were randomly allocated equally to Plank 30 s training (P30) group and Plank 60 s training (P60) group. Participants were requested to perform 30 s or 60 s per set for 3 sets. Both P30 and P60 groups showed significantly increased shear rate, blood flow, systolic blood pressure and heart rate as compared to the pre-training (P<0.05). Only the P60 group showed significant increased in mean arterial blood pressure. The mean arterial blood pressure and systolic blood pressure of the P60 group were significantly higher than the P30 group. There was a significant decreased FMD in P60 group as compared to pre-training and post-training of P30 group. No change in FMD was observed in P30 group. In conclusion, impaired endothelial function was observed in the long duration plank exercise in untrained participants.
