Acute Effects Of Mental Stress-induced Arterial Stiffening On Aerobic Exercise Capacity

Transient mental stress (MS) has been reported to be associated with an increase in arterial stiffness. We have recently found that an acute decrease in arterial stiffness may enhance maximal aerobic capacity. However, whether an acute increase in arterial stiffness affects changes in maximal aerobic capacity remains unknown. PURPOSE: To examine whether an increase in arterial stiffness induced by an MS task could attenuate maximal aerobic capacity. METHODS: Eighteen sedentary males (21.7 ± 1.6 years) who did not engage in regular resistance or endurance training participated in the study. The participants completed an MS task trial involving mental arithmetic and a sedentary control (CON) trial, which consisted of seated rest in the exercise room, on separate days in a randomized, controlled, crossover design. Brachial-ankle pulse wave velocity (baPWV), an index of systemic arterial stiffness, along with blood pressure and heart rate, were measured at baseline and after the MS and CON trials. After these measurements, maximal oxygen uptake was assessed using a graded power test on an electronically braked cycle ergometer. RESULTS: There was no significant difference in baseline baPWV between the trials. Compared to baseline, baPWV was significantly higher immediately after the stress task in the MS trial and remained unchanged in the CON trial (MS: 1018 ± 119 to 1082 ± 115 cm/sec, P = 0.00001; CON: 1021 ± 106 to 1021 ± 115 cm/sec). In addition, baPWV immediately after the stress task in the MS trial was significantly higher than in the CON trial (MS: 1082 ± 115 vs. 1021 ± 115 cm/sec, P = 0.0004). No significant difference were observed between the trials or from baseline in terms of blood pressure or heart rate at any time point after either trial. Maximal oxygen uptake was significantly lower in the MS trial (38.7 ± 3.6 mL/kg/min, P = 0.0002) compared to the CON trial (40.6 ± 4.1 mL/kg/min). CONCLUSIONS: These results suggest that an acute MS-induced increase in arterial stiffness may contribute to a decline in aerobic exercise capacity.