The comparison of endothelial function of moderate intensity interval exercise with continuous exercise in healthy men

BACKGROUND/AIM: Exercise enhances endothelium-dependent vasodilation; however, it is unclear whether intermittent exercise has a different effect on vascular endothelial function compared to continuous exercise. This study aimed to compare vascular endothelial function following intermittent exercise including short rest intervals with continuous exercise, both at the anaerobic threshold level. MATERIALS AND METHODS: Peak oxygen consumption (VO(2) peak) and anaerobic threshold were measured in physically active healthy young men (n = 12) by breath-by-breath analysis. After completion of intermittent exercise consisting of eight 1-min long intervals at the anaerobic threshold intensity with 75-s rest periods, total work was calculated. Equivalent work was done during continuous exercise. Immediately after the two exercise periods, venous blood lactate, endothelial nitric oxide synthase (eNOS), endothelin-1, N-terminal proANP (NTproANP), N-terminal proBNP (NTproBNP), and N-terminal proCNP (NTproCNP) levels were measured. Brachial artery flow-mediated dilatation (FMD) was measured before exercise and 30 min after exercise. RESULTS: Mean VO(2) peak level was 33.42 ± 5.9 ml/min/kg and anaerobic threshold level was 47.33 ± 5.85%. Lactate levels following continuous exercise were higher than levels following intermittent exercise (27.76 ± 7.43 mg/dl, 18.54 ± 4.87 mg/dl respectively; p˂0.05). Endothelin-1, eNOS, NTproANP, NTproBNP, and NTproCNP levels were similar after both modalities of exercise (p > 0.05). No significant difference was found in FMD response when comparing intermittent and continuous exercise (7.05 ± 15.11%, 2.49 ± 16.24% respectively; p > 0.05). CONCLUSION: Since blood lactate levels are higher following continuous exercise, individuals who find difficulty exercising may prefer an intermittent form of exercise. However, both intermittent and continuous exercise at the anaerobic threshold level seem to not produce a significant acute change in endothelial function in healthy men.