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. 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-1 (LCOF), 3 mg·kg-1 (MCOF) and 6 mg·kg-1 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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
DOUBLE
Enrollment
69
Caffeinated versions of instant coffee were prepared in 600 ml hot water (approximately 65°C) and served in a mug. Participants ingested 0.12 g·kg-1 of decaffeinated coffee + 0.04 g·kg-1 of caffeinated coffee to achieve 1.5 mg·kg-1 of caffeine intake in LCOF 60-min before the experimental trial.
Caffeinated versions of instant coffee were prepared in 600 ml hot water (approximately 65°C) and served in a mug. Participants ingested 0.08 g·kg-1 of decaffeinated coffee + 0.08 g·kg-1 of caffeinated coffee to achieve 3 mg·kg-1 of caffeine intake in MCOF 60-min before the experimental trial.
Caffeinated versions of instant coffee were prepared in 600 ml hot water (approximately 65°C) and served in a mug. Participants ingested 0.16 g·kg-1 of caffeinated coffee to achieve 6 mg·kg-1 of caffeine intake in HCOF 60-min before the experimental trial.
Decaffeinated versions of instant coffee were prepared in 600 ml hot water (approximately 65°C) and served in a mug. Participants ingested 0.16 g·kg-1 of decaffeinated coffee in PLA 60-min before the experimental trial.
Ankara University's Department of Sports Science
Ankara, Turkey (Türkiye)
Upper- and Lower-boy muscular endurance
Muscular endurance assessed during bench press and squat exercises using 60% of one-repetition maximum (1RM). Performance expressed as total weight lifted (kg).
Time frame: 60 minutes after caffeine or placebo ingestion (during each experimental trial)
Upper- and lower-body strenght
Maximal dynamic strength assessed using one-repetition maximum (1RM) tests in the squat and bench press exercises (kg).
Time frame: 60 minutes after caffeine or placebo ingestion (during each experimental trial)
Sprint Performance
Peak power output and mean power output measured during a 15-second Wingate anaerobic test on a cycle ergometer (W/kg).
Time frame: 60 minutes after caffeine or placebo ingestion (during each experimental trial)
Cognitive performance
Reaction time (ms) and accuracy measured using a modified arrow flanker task.
Time frame: Baseline (before caffeine ingestion) and 60 minutes after caffeine or placebo ingestion.
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