Dietary Supplement, Exercise
Conditions
Brief summary
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.
Interventions
DIETARY_SUPPLEMENTLow Dose Caffeine (LCOF)
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.
DIETARY_SUPPLEMENTModerate Dose Caffeine (MCOF)
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.
DIETARY_SUPPLEMENTHigh Dose Caffeine (HCOF)
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.
DIETARY_SUPPLEMENTPlacebo (PLA)
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.
Sponsors
Northumbria University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
DOUBLE (Subject, Investigator)
Masking description
Supplements were allocated in a randomised order and double-blinding design was implemented by an independent technician who did not take part in the study. The randomisation and blinding were held until the end of the study.
Eligibility
Sex/Gender
ALL
Age
18 Years to 30 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy individuals * Physically active individuals * Non-smokers * Age between 18 and 30 years * Free from respiratory insufficiency * Free from cardiovascular disease * Free from neuromuscular disorders * Free from musculoskeletal injury within the previous 6 months
Exclusion criteria
* Diagnosed cardiovascular disease * Neuromuscular disease * Current limb injury * History of limb injury requiring treatment within the previous 6 months * Chronic respiratory disease or treatment for chronic respiratory conditions
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Upper- and Lower-boy muscular endurance | 60 minutes after caffeine or placebo ingestion (during each experimental trial) | Muscular endurance assessed during bench press and squat exercises using 60% of one-repetition maximum (1RM). Performance expressed as total weight lifted (kg). |
| Upper- and lower-body strenght | 60 minutes after caffeine or placebo ingestion (during each experimental trial) | Maximal dynamic strength assessed using one-repetition maximum (1RM) tests in the squat and bench press exercises (kg). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Sprint Performance | 60 minutes after caffeine or placebo ingestion (during each experimental trial) | Peak power output and mean power output measured during a 15-second Wingate anaerobic test on a cycle ergometer (W/kg). |
| Cognitive performance | Baseline (before caffeine ingestion) and 60 minutes after caffeine or placebo ingestion. | Reaction time (ms) and accuracy measured using a modified arrow flanker task. |
Countries
Turkey (Türkiye)
Outcome results
None listed