The aim of this study was to analyse the effect of mental fatigue on passing decision‐making in professional soccer athletes. A controlled and counterbalanced cross‐over design was adopted consisting of three visits with a 1‐week interval between sessions. Twenty professional soccer male athletes participated in three randomized conditions divided into three visits: control, 15‐min Stroop task, and 30‐min Stroop task. Inhibitory control was accessed by the Stroop task (accuracy and response time) before and after induced mental fatigue protocol. The athletes played a training match (90‐min) following the experimental conditions. The Game Performance Assessment Instrument (GPAI) was used for the passing decision‐making analysis. The GPAI analysis showed impaired passing decision‐making performance following the 30‐min Stroop task compared with the 15‐min and control condition (F _(2,17) = 6.99, p = .01). Moreover, an increase in response time during the Stroop task was found following 30‐min Stroop task condition (F _(2,17) = 6.57, p = .03) compared to 15‐min of Stroop task and control conditions. Prolonged cognitive tasks may be considered a mediating factor in passing decision‐making performance in male professional soccer athletes throughout a full‐length training match. Thus, athletes should avoid highly demanding‐cognitive tasks before a soccer match. Future studies are required to explore more ecological cognitive tasks to induce mental fatigue (i.e. smartphones and video‐games) and their effects on other performance indicators (e.g. physical, technical, tactical) in a full‐length training match setting.

Given the accuracy in data collection, radar-based local positioning systems (LPS) are a promising technology to monitor training load in team sports. The objective of this study was to systematically review articles that compare the validity and reliability of LPS to other electronic performance and tracking system (EPTS) in team sports. The authors searched three electronic databases (SPORTDiscus, PubMed, and Web of Science) to identify relevant studies published by October 21, 2019. A Boolean search was performed, including sport (population), search terms related to intervention technology (intervention technology), and outcome measures of the technology (outcomes). Seven studies evaluated the validity and reliability of LPS in team sports in comparison with other EPTS, including semi-automatic video technology (VID) and Global Positioning System (GPS). Two articles compared LPS to VID, three articles compared LPS to GPS, and two articles compared LPS to both GPS and VID. LPS is considered a valid and reliable EPTS in the field of load monitoring of team sports, usually resulting in higher accuracy than VID or GPS. However, special care should be taken when analyzing load indicators at high speeds or different trajectories, since the validity and reliability depend on the EPTS itself.

This study aimed to analyze the effect of playing videogames and using social media applications on smartphones on decision-making and countermovement jump (CMJ) performance in amateur boxers. Twenty one boxers were enrolled in the study and were randomly assigned to all three experimental conditions [smartphone (30SMA), videogame (30VID), and control (CON)]. CMJ was measured before and 30-min after each experimental condition. The athletes ran simulated combat recorded for decision-making analysis. The boxers watched coaching videos (CON), used social media applications on smartphones (30SMA), and played video games (30VID) for 30 min just before the combat simulation. Both attack and defense decision-making performance were worse in both 30SMA and 30VID conditions compared to the CON condition (p = 0.001). Regarding CMJ, despite no condition effect (p = 0.96) been obtained, a time effect (p = 0.001) was observed; So, it was found a decrease in CMJ performance after all experimental conditions (p = 0.001), with no difference between them. Using social media applications on smartphones and playing video game impairs decision-making performance in amateur boxers, with no harms for CMJ performance.

Discovering any performance degradation effect of racing swimmers’ use of social media smartphone apps might lead to new training and race preparation protocols, including pre-meet smartphone avoidance. This study’s objective was to analyze the performance effects of using smartphone social media apps on the 50, 100, and 200-m freestyle among 25 high-level swimmers. Each participant performed the three race distances in two conditions: with smartphone app exposure (50-MF, 100-MF, and 200-MF) and without (50-CON, 100-CON, and 200-CON). We randomized the order of these two conditions across participants. While smartphone app use was not associated with statistically significant performance differences on the shortest race (50CON versus 50MF), a repeated measures ANOVA showed a significant condition × time interaction for the swimmers’100-m freestyle performance (p = 0.01), with a significantly slower performance following smartphone app use evident in the last half of this race (p = 0.02) but not in the first half (p = 0.41). We also found a condition × time interaction in the same direction (slower for swimmers who used the smartphone app) for the 200-m freestyle performance (p = 0.01), with the slower performance occurring in the second (p = 0.01) but not the first (p = 0.91), third (p = 0.07) or fourth (p = 0.06) quarters of this race. Thus, prolonged smartphone social media app use was associated with reduced performance from elite swimmers on the 100- and 200- but not the 50-m freestyle.

We studied the effects of repeated inducements of mental fatigue (MF) from using social media on smartphones immediately before training sessions by young male volleyball athletes, focusing specifically on their decision-making, endurance, and countermovement jump performance (CMJ). We pair-matched 24 participants according to their decision-making abilities and then, randomly assigned them to one of two 4-week block training groups: control (CON) and smartphone use (SMA). For a 30-minute period before each training session, the CON group watched TV and the SMA group used social media apps on smartphones. We found a significant group x time interaction effect for decision making (attack, p = 0.03; passing, p = 0.02) during training blocks. More specifically, only the CON group improved their decision making (attack, p = 0.03; passing, p = 0.02). Both groups significantly improved their CMJ performance (p = .01), with no significant group x time interaction effect for CMJ (p = 0.91). Neither group significantly improved their endurance (p = 0.56). We concluded that 30-minutes of repetitive social media app use on a smartphone immediately before 4-weeks of volleyball training sessions negatively affected decision-making in young male volleyball athletes.

We investigated the acute effects of mental fatigue induced by 30-minute use of smartphone social network apps on volume load in resistance training among recreationally trained adults. Sixteen (n = 16) adults of both sexes performed three sets of a half back-squat exercise to failure with 80% of 15RM, interspersed with 3-minutes of passive recovery between sets, before and after two different cognitive tasks: (a) use of smartphone social network apps; and (b) watching a documentary. We assessed mechanical variables and ratings of perceived exertion during the strength exercise. Relative to the documentary-viewing control condition, a 30-minute exposure to smartphone social network apps led participants toward increased perception of mental fatigue (p = 0.004) and lower volume-load during the strength exercise (p = 0.006). There were no significant differences in perceived exertion between conditions (p = 0.54), participants’ motivation (p = 0.277), intra-set mechanical variables (p > 0.05), or blood lactate concentrations (p = 0.36). Our findings of an isolated possible higher-than normal RPE without changes in physiological variables, accompanying the lower volume-load in the mentally-fatigued participants support psychological, rather than physiological, bases for mental fatigue effects.