Habitual Caffeine Intake Affects the Ergogenicity of Dosing Regimens on Muscular Endurance but Not on Sprint and Cognitive Performance in Men and Women

Purpose The impact of caffeine habituation on acute responses to different doses of caffeinated coffee has received minimal attention. This study aimed to investigate the effects of different doses of coffee on physical and cognitive performance in men and women with different levels of daily caffeine consumption. Methods Sixty-nine (35 women) athletes participated in this study, attending 4 experimental visits in a double-blind, randomized, crossover fashion: decaffeinated coffee (PLA), 1.5 mg/kg (LCOF), 3 mg/kg (MCOF) and 6 mg/kg of caffeine (HCOF) from coffee ingestion. Sixty min after coffee consumption, participants performed squat and bench press exercises (1 repetition maximum, 1RM), 60% of 1RM muscular endurance (ME), maximal sprinting, and cognitive performance (CP) was assessed. Participants were allocated into low (LGROUP), moderate (MGROUP), and high (HGROUP) caffeine consumption groups. Results Caffeine ingestion did not improve 1RM squat (p = 0.62) or bench press (p = 0.74), and ME of bench press (p = 0.91). Squat ME was increased with MCOF and HCOF in LGROUP and MGROUP, both in men and women. However, in HGROUP, enhancement was only seen with HCOF (p = 0.01). Sprint performance was enhanced with only HCOF in all consumption groups and sexes (p = 0.01). CP was significantly higher with HCOF (p = 0.01) compared to PLA, LCOF, and MCOF regardless of habituation level and sex. RPE and HR values did not change between trials, sexes, and consumption groups (p > 0.05). Conclusion These results suggest that 3 and 6 mg/kg of caffeine increases physical or cognitive performance, but the required dose for muscular endurance enhancement can be related to the habituation level of participants. Trial registration The study was registered on clinicaltrials.gov with ID of NCT07474753 on March 11, 2026.