3.1. Participant Characteristics
IRREGULAR MENSTRUAL CYCLE
Of the 52 total participants (26 males and 26 females), 28 (54%) reported being concurrently trained (i.e., engaging regularly in both endurance, resistance, and/or concurrent training sessions); 20 (38%) were exclusively resistance-trained; and 4 (8%) were exclusively endurance-trained. Across the entire sample, 37 participants (71%) identified primarily as White/Caucasian, 9 (17%) identified as Hispanic/Latino, 5 (10%) identified as Asian, and 1 (2%) identified as Black/African American. Overall, participants reported having consistently trained for the past 7.9 ± 4.9 years and reported consuming approximately 144 ± 53 mg caffeine per day at the time of enrollment. At the time of enrollment, 21 (81%) of the 26 female participants reported having a regular menstrual cycle, defined as menstrual periods occurring at regular intervals and no missed periods within the past six months. A total of 12 (54%) of the 26 female participants reported using hormonal contraception. Of these, seven (58%) reported using a combined oral contraceptive pill, three (25%) used a progestin-only pill, one (8%) used an implant, and one (8%) used a hormonal intrauterine device. Baseline participant characteristics in each of the three conditions are presented in 