2.1. Participants
The minimum required sample size was calculated using the software G*power (version 3.1.9.6; Kiel University, Kiel, Germany). The F test family (repeated measures, within factors) was selected with three periods (Pre-Ramadan, last week of Ramadan, and Post-Ramadan), two times of day (Morning and evening), and two supplementation conditions (Caff and placebo). Based on physical performance data from Bougrine et al. [The selection of players’ chronotypes was based on the Horne and Ostberg (1976) self-assessment questionnaires (MEQ) [