Effect of Acute Exercise and Cycling Desk on Energy Intake and Appetite Response to Mental Work: The CORTEX Study

Background: While mental work has been shown to favor overconsumption, the present study compared the effect of a cognitive task alone, followed by acute exercise, or performed on a cycling desk, on short-term food intake and appetite in adults.

Methods: A total of 19 normal-weight adults randomly completed: resting session (CON), 30-minute cognitive task (CT), 30-minute cognitive task followed by a 15-minute high-intensity interval exercise bout (CT-EX), and 30-minute cognitive task performed on a cycling desk (CT-CD). Energy expenditure was estimated (heart rate-workload relationship), and energy intake (EI; ad libitum) and appetite (visual analog scales) were assessed.

Results: Energy expenditure was higher in CT-EX (P < .001) compared with the other conditions and in CT-CD compared with CON and CT (P < .01). EI was higher in CON (P < .05) and CT-CD compared with CT (P < .01). Relative EI was higher in CON compared with CT (P < .05) and lower in CT-EX compared with CT, CT-CD, and CON (all Ps < .001). Area under the curve desire to eat was higher in CON compared with CT (P < .05) and CT-EX (P < .01). Area under the curve prospective food consumption was higher in CON compared with CT-EX (P < .01). Overall composite appetite score was not different between conditions.

Conclusion: While cycling desks are recommended to break up sedentary time, the induced increase in energy expenditure might not be enough to significantly reduce overall short-term relative EI after mental work.