Effect of chronotype on rating of perceived exertion in active young people

Purpose The study aimed to evaluate the effect of chronotype on aerobic performance, heart rate (HR) and Rating of Perceived Exertion (RPE). Methods The Morningness-Eveningness Questionnaire (MEQ) was administered to determine the chronotype's students of the School of Exercise Sciences, University of Milan. To investigate the effect of chronotype on aerobic performance, HR and RPE, 22 participants (11 M-types, 11 E-types) performed the Cooper test at 9:00 a.m. and at 5:00 p.m. Before and after the Cooper test, the RPE was detected using the Borg Scale CR 0-10. Results The two-way ANOVA showed an interaction between chronotype, time span and RPE. Specifically, M-types perceived less effort in the morning compared to the afternoon session (p < 0.05), both before (CR-10: 1.10.8 vs 2.5 +/- 1.3) and after exercise (CR-10: 7.4 +/- 1 vs 8.6 +/- 1). E-types felt more fatigued in the morning than in the afternoon session (p < 0.05), both before (CR-10: 2.4 +/- 1.4 vs 1.1 +/- 1.1) and after exercise (CR-10: 8.4 +/- 0.6 vs 7.5 +/- 0.7). Moreover, in the morning session, E-types had a greater perception of the effort (CR-10: 2.4 +/- 1.4 vs 8.4 +/- 0.6) than M-types (CR-10: 1.1 +/- 0.8 vs 7.4 +/- 1). Instead, in the afternoon session, M-types showed higher RPE values (CR-10: 2.5 +/- 1.3 vs 8.6 +/- 1) than E-types (CR-10: 1.1 +/- 1.1 vs 7.5 +/- 0.7). Cooper Test and HR results did not show statistically significant differences. On the other hand, no interaction was found between chronotype, day time and performance or HR. Conclusions M-types perceive higher effort in the afternoon session; by contrast, E-types show an opposite trend and are more fatigued in the morning session. These findings may be useful to the coach to plane tailored training programs.