How the time and type of physical education lessons affect attention capacity and cortisol levels in primary school children

Limited research has investigated the influence of different types of physical education (PE) lessons on cortisol (C) concentration and attention capacity in a school setting, particularly regarding circadian effects. This study aimed to: (i) compare the effect of a curricular PE lesson and a cognitively demanding PE lesson on C levels and attention capacity; (ii) evaluate the impact of the time of PE lessons (early morning vs. before lunch vs. after lunch) on these variables; (iii) explore the relationship between variations in C levels and attention capacity, assessing whether such variations differ according to time and type of PE lesson. A total of 111 children (9–11 years of age) randomly completed a curricular PE lesson and a cognitively demanding PE lesson of the same intensity (HR > 139 bpm) and duration (60 min). Saliva samples and d2 Test of attention were collected immediately before and immediately after each lesson to assess changes in C levels and attention capacity (total number of items processed, percentage of errors, concentration performance).Changes in total number of items processed and in concentration performance differed significantly between curricular and cognitively demanding PE lessons (39.7 ± 45.7 vs. 13.4 ± 46.4 and 16.0 ± 19.1 vs. 5.30 ± 35.0 score, respectively; p ≤ 0.05) with a medium effect size (ƞ2 = 0.06). Moreover, lesson timing significantly influenced changes in total number of items processed, concentration performance, and C levels with a medium effect size (ƞ2 = 0.06). Significant relationships were found between lesson time and changes in C levels, total number of items processed and concentration performance, in both types of lesson. Both curricular and cognitively demanding PE lessons improved attention and reduced C levels, with curricular PE lesson showing a greater impact on attentional performance. PE lesson time influenced cognitive improvements and C reduction, suggesting PE acts as a psychological distractor. However, attentional benefits were not directly related to C-level changes.