The purpose of this study was to determine whether the acute ergogenic effects of caffeine differ according to the velocity metric used to assess strength performance against different relative loads. Thirteen resistance-trained men completed a triple-blind, randomized, placebo-controlled, crossover study. Participants ingested either caffeine (3 mg·kg-1) or a placebo 60 min before performing bench press and back squat exercises at 25%, 50%, 75%, and 90% of one-repetition maximum (1RM). Mean velocity (MV) and mean propulsive velocity (MPV) were simultaneously recorded using a linear position transducer
Who can participate
Age range
18 Years – 35 Years
Sex
MALE
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
* Age between 18 and 35 years.
* Body Mass Index (BMI) \< 25 kg/m².
* Resistance-trained individuals (more than 6 months of structured training).
* Healthy men and women without neurological, cardiometabolic, immunological, or physical conditions that prevent them from exercising.
* Participants must be able to perform the tests described in the following section.
Exclusion Criteria:
* History of neuromuscular diseases, heart disease, or conditions that may affect liver or muscle metabolism.
* Use of drugs, stimulants, or sports supplements that could interfere with the dietary supplement used in the study.
* Sedentary habits (less than 150 minutes/week of moderate exercise).
* Having undergone prolonged periods of physical inactivity in the 6 months prior to the study.
* Engaging in strenuous exercise within 48 hours prior to the tests.• Failure to replicate the same food intake on both experimental days.
* Consumption of caffeine or any other stimulant after 6 pm on the day before the tests, to avoid headaches, discomfort, or lethargy in regular caffeine consumers.
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Velocity metrics against different relative loads of one-repetition maximum
Timeframe: Through study completion, an average of 3 weeks