Background
Sedentary behavior is negatively associated with cognition and mood. University students are often engaged in high levels of sedentary behavior, which may negatively impact learning.

Objectives
To investigate the acute effect of light-intensity physical activity (LIPA) breaks on attention, executive functioning, and mood during prolonged sitting. We compared sitting with frequent interruptions of LIPA (INTERRUPT) with two control conditions: (1) with a non-demanding cognitive task (SIT), (2) with a demanding cognitive task (COGN).

Methods
21 healthy adults (15 females; age = 24.0 ± 3.0 years; BMI = 23.0 ± 2.1 kg/m²) completed three conditions in a randomized crossover design. In the SIT condition, participants sat for four hours while watching a series of documentaries. In the COGN condition, participants took the online cognitive demanding test while sitting for 4 hours. In the INTERRUPT condition, the subject broke this sitting regime every 25 minutes for a 5-minute walk.  Attention, executive functioning (inhibition, task shifting, and memory updating), and mood were tested before and after each condition.

Results
Linear mixed models analyses showed that frequently interrupting prolonged sitting with LIPA (INTERRUPT) significantly improved task shifting compared to SIT. However, a comparable effect was observed in the condition with a demanding cognitive task (COGN). No acute effects on attention, the other two executive function domains, or mood were found.

Conclusions
Acute LIPA or cognitive demanding activities have a selective impact on cognitive performance. Thus, when university students sit, both physical and cognitive activity help to maintain cognitive performance and mood. In future research, it is recommended to take activity type during sitting into consideration and to investigate the effect of LIPA under real learning situations.