Heart Rate and Oxygen Consumption during Mental Arithmetic, a Video Game, and Graded Exercise: Further Evidence of Metabolically‐Exaggerated Cardiac Adjustments?

ABSTRACT Heart rate, plus various metabolic and ventilatory indices, were monitored while 20 young male subjects were exposed to a video game and a stressful mental arithmetic task. Measurements were also made while subjects undertook graded isotonic exercise. All measures changed as a function of psychological challenge, and during exercise physiological activity increased as an orderly function of workload. For each subject, heart rate was plotted against oxygen consumption over the various exercise loads. For the majority of subjects the analogous data points for the video game and mental arithmetic lay reliably above the exercise heart rate‐oxygen consumption regression lines. When these regression lines were used to predict heart rate values during psychological challenge, the predicted values were significantly less than the values actually recorded for both tasks; although the discrepancy between predicted and actual values was on average greater with mental arithmetic, the difference was not statistically reliable. Pre‐stressor baseline conditions were also associated with heart rate levels greater than predicted, albeit to a lesser extent. Finally, while both stressors produced heart rate adjustments additional to expectancies, inter‐task consistency was low.