[Effects of resistance combined with aerobic chrono-exercise on common carotid artery elasticity and hemodynamics in young men].

The purpose of the present study was to investigate the effects of resistance combined with aerobic chrono-exercise on the common carotid artery elasticity and hemodynamics. 24 healthy young men (21.96±0.43 years old) underwent a single acute resistance combined with aerobic exercise intervention at eight time periods (6, 8, 10, 12, 14, 16, 18, and 20 o'clock). The axial flow velocity and diameter waveforms of the common carotid artery were measured, and the hemodynamics were calculated using the classical hemodynamic theory before exercise, immediately after exercise, 10 min and 20 min after exercise. The results showed that during exercise recovery, systolic and mean pressures decreased more markedly after exercise at 8 o'clock (P < 0.05); At 20 min post-exercise, arterial stiffness index and pressure-strain elastic modulus after exercise at 6 o'clock were reduced compared with the resting state, but were significantly elevated after exercise at 20 o'clock (P < 0.05). Immediately after exercise, the pressure rise was higher after exercise at 6 o'clock and the mean wall shear stress was higher after exercise at 20 o'clock (P < 0.05). These results suggest that resistance combined with aerobic chrono-exercise produces different effects on common carotid artery hemodynamics in young men. A single acute session of resistance combined with aerobic exercise at 8 o'clock is more effective in lowering blood pressure. Exercise at 6 o'clock is beneficial to improve arterial elasticity but is not recommended for young male individuals with cardiovascular disease risks because of the excessive increase in blood pressure immediately after exercise. Exercise at 20 o'clock is more effective in improving wall shear stress but is accompanied by elevated arterial stiffness indices and pressure-strain elastic modulus. These results provide a scientific basis for healthy young men in choosing the time of exercise by exploring the common carotid artery elasticity and hemodynamic-related indices.