Karla A. Kubitz
Karla A. Kubitz and Konstantinos Pothakos
In the present study, participants were randomly assigned to an exercise or a nonexercise group to measure brain activation (spontaneous EEG activity), affect, and cognitive functioning before and after a 15-min treatment period. Exercisers (a) sat quietly for 5 min, (b) exercised for 15 min, (c) recovered for 5 min, and (d) completed a 15-min vigilance task. Nonexercisers did not exercise. There was a significant (a) Condition × Band × Time interaction for EEG activity, (b) Condition × Time interaction for Activation-Deactivation Adjective Checklist (AD ACL) scores, and (c) Condition × Time interaction for reaction times (RTs). Post hoc tests showed (a) no significant group effects at the baseline and 15-min vigilance periods, and (b) significant group effects at the postexercise and 5-min vigilance periods. Exercisers had lower levels of brain activation (i.e., more theta and alpha activity and less beta activity), higher AD ACL scores, and slower RTs than nonexercisers during these periods.
Karla A. Kubitz and Daniel M. Landers
This study examined the effects of an 8-week aerobic training program on cardiovascular responses to mental stress. Dependent variables included electrocardiographic activity, blood pressure, electroencephalographic (EEG) activity, state anxiety, and state anger. Quantification of indicators of sympathetic, parasympathetic, and central nervous system activity (i.e., respiratory sinus arrhythmia, T-wave amplitude, and EEG activity, respectively) allowed examination of possible underlying mechanisms. Subjects (n = 24) were randomly assigned to experimental (training) and control (no training) conditions. Pre- and posttesting examined cardiorespiratory fitness and responses to mental stress (i.e., Stroop and mental arithmetic tasks). MANOVAs identified a significant effect on cardiorespiratory fitness, heart rate, respiratory sinus arrhythmia, and EEG alpha laterality. The results appear consistent with the hypothesis that enhanced parasympathetic nervous system activity and decreased central nervous system laterality serve as mechanisms underlying certain aerobic training effects.