Objective: This study aimed to investigate the repeated effect of social media on smartphones immediately before training sessions on inhibitory control (Stroop task), endurance (tethered swimming), countermovement jump (CMJ), and swimming performance (50, 100, and 400-m freestyle) in high-level female swimmers. Methods: It is a randomized and experimental investigation with parallel groups. Twenty-two participants underwent the eight weeks of the experiment. The swimmers (eight to twelve sessions per week with 15.9 ± 1.6 hours/week, and training experience of ~ 5.6 years) were randomized in two groups: control (CON, n = 11) and smartphone (SMA, n = 11). Immediately before each training session, the CON group watched videos about Olympic Games for 30-min. The SMA group used social network smartphone apps during 30-min. The inhibitory control, endurance, CMJ, and swimming performance were measured before and after the eight weeks of intervention. Results: No group x time interaction for 50-m freestyle (F(4, 18) = 1.04; p = .33; η2 = 0.09) and CMJ performance (F(4, 18) = 0.31; p = .58; η2 = 0.03) was found. Both experimental groups improved CMJ (F(2, 20) = 8.71; p = .01; η2 = 0.46). Only the CON group improved the 100-m (p = .02), 400-m freestyle (p = .01), and endurance performance (p = .01). The CON group improved the inhibitory control response (p = .01). Conclusion: It is concluded that the repeated effect of social media on smartphones immediately before swimming training sessions might reduce or nullify training gains on swimming and endurance performance.
Keywords: Cognition; fatigue; neuroscience; performance; psychology.