Effects of prolonged engagement in alternating video games and smartphone use on muscle endurance and physical activity intentions in young healthy adults

Recent studies suggest a negative effect of acute smartphone use or video games on physical performances. This study examined the effect of alternating between video games and smartphone scrolling on social networks on subsequent muscle endurance performance and physical activity intention in young adults.Thirty-eight young adults (19±1 y.o.; 13 female and 25 male). Participants engaged either in 90 minutes alternating between video gaming and scrolling on smartphone (VGSS condition) or watching documentaries (control condition). Perceived workload, mental fatigue, motivation and boredom of each condition were assessed. Cognitive performance and physical activity intention were measured pre-post VGSS and control condition. Then, participants performed a knee extensors endurance task until exhaustion at 20% of their maximal voluntary peak force.Participants perceived the VGSS as more demanding than watching documentaries, but only a slight increase in mental fatigue and no difference between conditions in cognitive performance was observed. Muscle endurance performance did not differ after VGSS or documentary watching, and physical activity intention decreased regardless of condition.Engaging in VGSS did not induce a specific state of mental fatigue, explaining the absence of impaired muscle endurance performance. Both conditions negatively impacted physical activity intentions, suggesting that sitting in front of a screen impairs intentions to be active.