Cardiovascular response of trained preadolescent boys to mental challenge

To compare the cardiovascular reactivity response to mental challenge of aerobically trained and untrained preadolescent boys.

Heart rate (HR) and blood pressure, as well as stroke volume, total peripheral resistance, rate pressure product, and cardiac contractility response in 15 aerobically trained (10.3 yr) and 15 untrained (9.5 yr) subjects during and recovering from the Stroop task and a computer game (Tetris) were examined. Cardiac vagal activity was also assessed using time series analysis of heart period variability (HPV(ts)).

Untrained compared with trained subjects made significantly more errors during Stroop, whereas performance on Tetris was similar. Trained subjects had significantly lower (P < 0.05) HR and significantly greater cardiac vagal activity at rest. Both groups had significant increases in HR, peripheral resistance, systolic and diastolic blood pressures, rate pressure product, and a significant decrease in vagal activity during Stroop. In contrast, only diastolic blood pressure increased and vagal activity decreased during Tetris. Cardiac contractility of both groups failed to increase during either stressor. Trained compared with untrained subjects had significantly lower absolute HR during and recovering from Stroop. Also HR and vagal activity change, relative to baseline, was significantly greater for the trained during Stroop. During and recovering from Tetris, absolute HR was significantly less for the trained subjects, but change scores were not significantly different.

The greater HR and vagal activity change of trained subjects to the Stroop suggests greater cardiac reactivity to mental challenge.