@Article{Dridi2026,
journal="Biology of Sport",
issn="0860-021X",
volume="43",
number="1",
year="2026",
title="Evening smartphone exposure impairs sleep quality and next-day 
performance in elite soccer players: a randomized controlled trial",
abstract="This study aimed to examine the effects of pre-bedtime smartphone use on sleep quality and athletic performance in soccer players while also investigating potential time-of-day variations. In thisrandomized controlled crossover trial, 16 male elite-level players were assigned to either use a smartphone for two hours prior to bedtime or read magazines (control), separated by a one-week washout period. Participants completed morning and afternoon performance tests (cognitive and physical assessments) and sleep quality measurements. Nocturnalsmartphone use significantly impaired sleep quality, increasing sleepiness after days 3 and 5 (p   < 0.01;  d =5.74,  d =5.72, respectively), decreasing total sleep time, increasing sleep onset latency, and reducing sleep efficiency (all   p < 0.01;  d =1,  d =4.59). Cognitive performance initially showed improved afternoon results, although following five days of smartphone use, this pattern reversed with enhanced morning performance ( p  < 0.01;  d =0.53,  d =1.48). Simple and choice reaction times deteriorated significantly in afternoon sessions compared to both baseline and control conditions ( p  < 0.01;  d =0.96–3.47). Physical performance tests revealed decreased jumping ability and slower reactive agility times following five nights of smartphone use, particularly in afternoon sessions ( p  < 0.01;  d =0.85 0.91). Five consecutive nights of pre-bedtime smartphone use impaired sleep quality and both cognitive and physical performance in elite soccer players, with stronger effects in afternoon sessions. These findings emphasize the importance of implementing device-free periods prior to bedtime and potentially adjusting training schedules when evening screen exposure is unavoidable. Future research should explore countermeasures for managing evening device exposure in elite athletes.",
author="Dridi, Nadia
and Souissi, Mohamed Abdelkader
and Dridi, Rim
and Ceylan, Halil İbrahim
and Bragazzi, Nicola
and Salem, Atef
and Fekih, Sofien
and Chtara, Mokhtar
and Mkaouer, Bessem
and Chtourou, Hamdi
and Dergaa, Ismail
and Souissi, Nizar
and Stefanica, Valentina
and Żmijewski, Piotr
and Morgans, Ryland",
pages="227--242",
doi="10.5114/biolsport.2026.152348",
url="http://dx.doi.org/10.5114/biolsport.2026.152348"
}