AthletesPOWER-CAFNCT07520864
Effects of Caffeine on Elite Weightlifting Performance
A study testing Caffeine in people with Athletes, run by Universidad Pontificia Comillas at 1 site in Spain.
Trial summary
Weightlifting is a high-intensity strength-power sport where performance depends on maximal force, power output, and technical execution in the snatch and clean and jerk. Due to the sport's short-duration efforts, the ATP-PCr system predominates, with glycolysis supporting recovery between attempts. Read more about this study
- Who is it for?
- Ages 16 to 35 yearsHealthy volunteers can take part
- Conditions the study is for
- Athletes
- What is being tested?
- Caffeine
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 14 participants
- Where
- 1 siteSpain
- Study dates
- 1 Mar 2026to 25 Mar 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 16 to 35 years
- All sexes
- Healthy volunteers accepted
- Child, Adult
Who may be able to join
- Possession of a valid weightlifting federation license
- At least two years of weightlifting experience
- Free from injury or illness at the time of testing
Who cannot join
- Caffeine intolerance
- Presence of any chronic disease or injury within the month preceding the study
- Habitual caffeine consumption exceeding 100 mg/day
- Use of medications or dietary supplements during the study period
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Is Caffeine the Secret Ingredient for Elite Weightlifting Performance? It Helps-But Don't Expect Miracles
Weightlifting is a high-intensity strength-power sport where performance depends on maximal force, power output, and technical execution in the snatch and clean and jerk. Due to the sport's short-duration efforts, the ATP-PCr system predominates, with glycolysis supporting recovery between attempts. Given these demands, ergogenic aids are commonly used. While some supplements show limited or inconsistent evidence, caffeine stands out as one of the most well-supported for enhancing strength and power, mainly through central nervous system stimulation. Although its benefits are well documented in other strength sports, research specifically in Olympic weightlifting is scarce. Therefore, this study aimed to examine the effects of caffeine on neuromuscular and competition performance in elite weightlifters, hypothesizing a positive effect.
Read the detailed description
Olympic weightlifting is a strength-power sport in which athletes aim to lift maximal loads in two highly technical movements: the snatch and the clean and jerk. Performance is determined by the Olympic Total, which combines the best successful attempts in both lifts. These movements are executed in very short durations (2-5 seconds) and require exceptionally high levels of force, power, neuromuscular coordination, and technical proficiency. Because athletes compete within bodyweight categories, relative strength and power are more critical than absolute values. The strength sport is characterized by extremely high mechanical outputs, with barbell velocities exceeding ~1.65 m/s in the snatch and ~0.88 m/s in the clean and jerk. These conditions generate some of the highest power outputs recorded in sport science, particularly during the second pull phase. From a physiological perspective, the ATP-PCr system predominates due to the explosive and brief nature of the efforts, although the glycolytic system contributes to recovery between attempts and supports repeated efforts in training.
Given these demands, ergogenic aids are often used to optimize performance. While some supplements such as pomegranate juice, BCAAs, and creatine have been associated with benefits in recovery, fatigue reduction, and strength, the supporting evidence is not always robust. In contrast, caffeine is one of the most evidence-based ergogenic aids, primarily acting through antagonism of adenosine receptors (A1 and A2A), which enhances neurotransmitter release (e.g., dopamine and acetylcholine) and improves central nervous system activation. Research has consistently shown that caffeine can enhance muscular strength, including improvements in one-repetition maximum, handgrip strength, and jump performance. Meta-analyses further support its role in increasing maximal strength and power output. Additionally, studies in related strength sports such as powerlifting have reported improvements in power output, movement velocity, velocity loss, and perceived exertion following caffeine ingestion. However, despite this strong body of evidence, research specifically focused on Olympic weightlifting remains limited, and there is a lack of direct evidence regarding both performance outcomes and potential side effects in this population.
Therefore, this study was designed to address this gap by examining the effects of caffeine ingestion on neuromuscular performance and simulated competition outcomes in elite weightlifters. The authors hypothesized that caffeine would enhance both neuromuscular and competitive performance in this population.
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PlaceboDietary supplement
Participants ingested an identical opaque capsule containing an inert substance (cellulose; Guinama, Valencia, Spain). The capsule was also consumed with 200 mL of water under researcher supervision. This condition served as a control to compare against the caffeine condition while maintaining blinding.
CaffeineDietary supplement
Participants ingested an opaque capsule containing 3 mg·kg-¹ of anhydrous caffeine (HSN, Granada, Spain). The capsule was consumed with 200 mL of water under researcher supervision to ensure compliance. This condition was designed to evaluate the ergogenic effects of caffeine on neuromuscular and weightlifting performance.
| Study group | Role | What they receive |
|---|---|---|
| Caffeine supplementation | Experimental | Participants ingested an opaque capsule containing 3 mg·kg-¹ of anhydrous caffeine (HSN, Granada, Spain). The capsule was consumed with 200 mL of water under direct supervision of the researchers to ensure compliance with the ingestion protocol. Receives: Dietary Supplement: Placebo |
| Placebo comparator | Placebo comparator | Participants ingested an opaque capsule containing an inert substance (cellulose; Guinama, Valencia, Spain). The capsule was consumed with 200 mL of water under direct supervision of the researchers to ensure compliance with the ingestion protocol. Receives: Dietary Supplement: Caffeine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Weightlifting competition
The simulated competition was conducted under official weightlifting conditions, following the standard order of lifts (snatch followed by clean and jerk) and using certified competition equipment. Athletes were allowed three attempts per lift, with up to 5 minutes of rest between attempts and a 10-minute rest period between lifts. Two experienced Level II coaches independently judged each lift, and only those approved by both were considered valid. From this protocol, key variables were derived, including competition strategy (load selected per attempt), competition results (best valid snatch, clean and jerk, and Olympic total), and the number of valid attempts performed in each exercise.
Measured: Four weeks
Secondary outcomes (6)
Countermovement jump
The countermovement jump (CMJ) was used to assess lower-body explosive performance. Participants started from an upright standing position with hands on hips to eliminate arm swing contribution. They then performed a rapid downward movement followed immediately by a maximal vertical jump, aiming to reach the highest possible height. The eccentric phase was self-selected, but participants were instructed to avoid any pause between the downward and upward phases. Multiple attempts were performed, and the best performance was retained for analysis.
Measured: 2 weeks
Deep squat jump
The deep squat jump (DSJ) was used to assess lower-body explosive performance from a static position. Participants began in a deep squat position (approximately 90° knee flexion or lower) with hands on hips to eliminate arm swing contribution. After holding the position briefly to remove any countermovement, they performed a maximal vertical jump, aiming to reach the highest possible height. This test isolates concentric force production by minimizing the contribution of the stretch-shortening cycle. Multiple attempts were performed, and the best performance was retained for analysis.
Measured: 2 weeks
isometric start position pull
The isometric start position pull was used to assess maximal isometric strength specific to weightlifting. Participants adopted the start position of the clean or snatch, with the bar fixed against an immovable structure at approximately mid-shin height. From this standardized position, they were instructed to pull maximally against the bar as quickly and forcefully as possible, maintaining proper lifting posture. Force output was recorded during the effort, and peak force was used for analysis. Multiple trials were performed, and the best result was retained.
Measured: 2 weeks
Isometric handgrip strength
The isometric handgrip strength test was used to assess maximal voluntary grip strength. Participants performed the test using a handgrip dynamometer, holding it in a standardized position with the arm extended alongside the body without touching the trunk. They were instructed to squeeze the dynamometer as forcefully as possible for a few seconds. Both dominant and non-dominant hands were tested, and multiple trials were performed. The highest value achieved for each hand was recorded for analysis.
Measured: 2 weeks
Rating of perceived exertion (RPE)
The rating of perceived exertion (RPE) was used to assess the subjective perception of effort during the session using scale 1-10 points. After each attempt in the simulated competition, participants reported their exertion using a standardized RPE scale. Additionally, a session-RPE was collected at the end of the protocol to reflect the overall perceived intensity of the entire session.
Measured: 2 weeks
Side effects questionnarie
The side-effects questionnaire was administered the morning after each experimental session to evaluate the presence and intensity of potential adverse effects associated with the intervention. The questionnaire assessed a range of subjective symptoms, including perceived energy levels, irritability, muscle pain or stiffness, headache, gastrointestinal discomfort, urine production, and sleep-related variables such as difficulty sleeping and overall sleep quality. Participants rated each item using a standardized scale to quantify their responses.
Measured: 2 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Apr 2026
- Study start1 Mar 2026
- Primary completion15 Mar 2026
- Study completion25 Mar 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for AthletesStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- A randomized, double-blind, placebo-controlled crossover design was employed. Each participant completed two identical evaluation sessions separated by 7 days to ensure adequate recovery and washout of substances. Both sessions were conducted at the same time of day (10:00 a.m.) at the Spanish National Team Training Facility in Madrid. Participants were instructed to replicate their dietary intake prior to each session, avoid strenuous exercise for 24 hours, maintain proper hydration (500 mL of water before arrival), and refrain from consuming supplements or stimulants (e.g., caffeine) for 48 hours before each session and until completing the side-effects questionnaire the following day. In each session, participants ingested an opaque capsule containing either 3 mg·kg-¹ of anhydrous caffeine (HSN, Granada, Spain) or a placebo (cellulose; Guinama, Valencia, Spain), administered with 200 mL of water under researcher supervision. Following ingestion, participants completed their habitua
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 14 participants (actual)
Sponsor and investigators
- Lead sponsor
- Universidad Pontificia Comillas
- Sponsor type
- University, hospital or other
- Collaborators
- Universidad Francisco de Vitoria, Universidad Rey Juan Carlos
- Responsible party
- Principal investigator, López Samanes, Universidad Pontificia Comillas
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07520864
- Sponsor's protocol ID
- UP__Comillas
- Acronym
- POWER-CAF
- Status last verified
- Apr 2026
- First submitted
- 2 Apr 2026
- Last updated
- 9 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data (IPD) will be made available upon reasonable request to the investigators.
Publications
Grgic J, Trexler ET, Lazinica B, Pedisic Z. Effects of caffeine intake on muscle strength and power: a systematic review and meta-analysis. J Int Soc Sports Nutr. 2018 Mar 5;15:11. doi: 10.1186/s12970-018-0216-0. eCollection 2018.
PubMed 29527137
Study at a glance
From the registry record, last updated by the sponsor on 9 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Is Caffeine the Secret Ingredient for Elite Weightlifting Performance? It Helps-But Don't Expect Miracles
- ClinicalTrials.gov ID
- NCT07520864
- Acronym / sponsor ID
- POWER-CAF / UP__Comillas
- Conditions
- Athletes
- Keywords
- dietary supplements, ergogenic aids, strength, caffeine
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 14 participants (actual)
- Lead sponsor
- Universidad Pontificia ComillasUniversity, hospital or other
- Collaborators
- Universidad Francisco de Vitoria, Universidad Rey Juan Carlos
- Study start
- 1 Mar 2026 (actual)
- Primary completion
- 15 Mar 2026 (actual)
- Study completion
- 25 Mar 2026 (actual)
- First posted
- 9 Apr 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Weightlifting is a high-intensity strength-power sport where performance depends on maximal force, power output, and technical execution in the snatch and clean and jerk. Due to the sport's short-duration efforts, the ATP-PCr system predominates, with glycolysis supporting recovery between attempts. Given these demands, ergogenic aids are commonly used. While some supplements show limited or inconsistent evidence, caffeine stands out as one of the most well-supported for enhancing strength and power, mainly through central nervous system stimulation. Although its benefits are well documented in other strength sports, research specifically in Olympic weightlifting is scarce. Therefore, this study aimed to examine the effects of caffeine on neuromuscular and competition performance in elite weightlifters, hypothesizing a positive effect.
Detailed description
Olympic weightlifting is a strength-power sport in which athletes aim to lift maximal loads in two highly technical movements: the snatch and the clean and jerk. Performance is determined by the Olympic Total, which combines the best successful attempts in both lifts. These movements are executed in very short durations (2-5 seconds) and require exceptionally high levels of force, power, neuromuscular coordination, and technical proficiency. Because athletes compete within bodyweight categories, relative strength and power are more critical than absolute values. The strength sport is characterized by extremely high mechanical outputs, with barbell velocities exceeding ~1.65 m/s in the snatch and ~0.88 m/s in the clean and jerk. These conditions generate some of the highest power outputs recorded in sport science, particularly during the second pull phase. From a physiological perspective, the ATP-PCr system predominates due to the explosive and brief nature of the efforts, although the glycolytic system contributes to recovery between attempts and supports repeated efforts in training.
Given these demands, ergogenic aids are often used to optimize performance. While some supplements such as pomegranate juice, BCAAs, and creatine have been associated with benefits in recovery, fatigue reduction, and strength, the supporting evidence is not always robust. In contrast, caffeine is one of the most evidence-based ergogenic aids, primarily acting through antagonism of adenosine receptors (A1 and A2A), which enhances neurotransmitter release (e.g., dopamine and acetylcholine) and improves central nervous system activation. Research has consistently shown that caffeine can enhance muscular strength, including improvements in one-repetition maximum, handgrip strength, and jump performance. Meta-analyses further support its role in increasing maximal strength and power output. Additionally, studies in related strength sports such as powerlifting have reported improvements in power output, movement velocity, velocity loss, and perceived exertion following caffeine ingestion. However, despite this strong body of evidence, research specifically focused on Olympic weightlifting remains limited, and there is a lack of direct evidence regarding both performance outcomes and potential side effects in this population.
Therefore, this study was designed to address this gap by examining the effects of caffeine ingestion on neuromuscular performance and simulated competition outcomes in elite weightlifters. The authors hypothesized that caffeine would enhance both neuromuscular and competitive performance in this population.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 2
- Model description
- A randomized, double-blind, placebo-controlled crossover design was employed. Each participant completed two identical evaluation sessions separated by 7 days to ensure adequate recovery and washout of substances. Both sessions were conducted at the same time of day (10:00 a.m.) at the Spanish National Team Training Facility in Madrid. Participants were instructed to replicate their dietary intake prior to each session, avoid strenuous exercise for 24 hours, maintain proper hydration (500 mL of water before arrival), and refrain from consuming supplements or stimulants (e.g., caffeine) for 48 hours before each session and until completing the side-effects questionnaire the following day. In each session, participants ingested an opaque capsule containing either 3 mg·kg-¹ of anhydrous caffeine (HSN, Granada, Spain) or a placebo (cellulose; Guinama, Valencia, Spain), administered with 200 mL of water under researcher supervision. Following ingestion, participants completed their habitua
| Arm | Type | Receives |
|---|---|---|
| Caffeine supplementation | Experimental | Dietary Supplement: PlaceboParticipants ingested an opaque capsule containing 3 mg·kg-¹ of anhydrous caffeine (HSN, Granada, Spain). The capsule was consumed with 200 mL of water under direct supervision of the researchers to ensure compliance with the ingestion protocol. |
| Placebo comparator | Placebo comparator | Dietary Supplement: CaffeineParticipants ingested an opaque capsule containing an inert substance (cellulose; Guinama, Valencia, Spain). The capsule was consumed with 200 mL of water under direct supervision of the researchers to ensure compliance with the ingestion protocol. |
Who may qualify
- Ages
- 16 to 35 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult
Key inclusion criteria (3 listed)
- Possession of a valid weightlifting federation license
- At least two years of weightlifting experience
- Free from injury or illness at the time of testing
Key exclusion criteria (4 listed)
- Caffeine intolerance
- Presence of any chronic disease or injury within the month preceding the study
- Habitual caffeine consumption exceeding 100 mg/day
- Use of medications or dietary supplements during the study period
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PlaceboParticipants ingested an identical opaque capsule containing an inert substance (cellulose; Guinama, Valencia, Spain). The capsule was also consumed with 200 mL of water under researcher supervision. This condition served as a control to compare against the caffeine condition while maintaining blinding. | Dietary supplement | Caffeine supplementation |
| CaffeineParticipants ingested an opaque capsule containing 3 mg·kg-¹ of anhydrous caffeine (HSN, Granada, Spain). The capsule was consumed with 200 mL of water under researcher supervision to ensure compliance. This condition was designed to evaluate the ergogenic effects of caffeine on neuromuscular and weightlifting performance. | Dietary supplement | Placebo comparator |
Primary outcome
Weightlifting competition
Time frame: Four weeks
The simulated competition was conducted under official weightlifting conditions, following the standard order of lifts (snatch followed by clean and jerk) and using certified competition equipment. Athletes were allowed three attempts per lift, with up to 5 minutes of rest between attempts and a 10-minute rest period between lifts. Two experienced Level II coaches independently judged each lift, and only those approved by both were considered valid. From this protocol, key variables were derived, including competition strategy (load selected per attempt), competition results (best valid snatch, clean and jerk, and Olympic total), and the number of valid attempts performed in each exercise.
6 secondary outcomes
Countermovement jump
Time frame: 2 weeks
Deep squat jump
Time frame: 2 weeks
isometric start position pull
Time frame: 2 weeks
Isometric handgrip strength
Time frame: 2 weeks
Rating of perceived exertion (RPE)
Time frame: 2 weeks
Side effects questionnarie
Time frame: 2 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Apr 2026.
- Background: PubMed 29527137Grgic J, Trexler ET, Lazinica B, Pedisic Z. Effects of caffeine intake on muscle strength and power: a systematic review and meta-analysis. J Int Soc Sports Nutr. 2018 Mar 5;15:11. doi: 10.1186/s12970-018-0216-0. eCollection 2018.
- Individual participant dataSharing planned: No. Individual participant data (IPD) will be made available upon reasonable request to the investigators.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Caffeine in people with Athletes, run by Universidad Pontificia Comillas at 1 site in Spain.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 9 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Spain. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Weightlifting competition (time frame: Four weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07520864, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Apr 2026.