HealthyNCT06547307
CYP1A2 and ADORA2A Genotypes and Endurance Performance.
A study testing Caffeine 2 mg, Caffeine 4 mg and Caffeine 0 mg in people with Healthy, run by Masaryk University at 1 site in Czechia.
Trial summary
The aim of this randomized, double-blind, placebo-controlled experiment will be to assess the potential effect of the selected gene polymorphism (CYP1A2, ADORA2A) on performance after caffeine ingestion. Read more about this study
- Who is it for?
- Ages 18 to 35 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- Caffeine 2 mg, Caffeine 4 mg and Caffeine 0 mg
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 60 participants
- Where
- 1 siteCzechia
- Study dates
- Aug 2024to Mar 2025
- 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 18 to 35 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- healthy person
- any training status
- within age limits
- without contraindications to perform the test on a bicycle trainer
- No contraindications to caffeine intake
Who cannot join
- Pregnancy
- Breast feeding
- Cardiovascular disease
- Hypertension
- Liver disease in the previous two months
- Taking drugs that can affect liver function
- Illness in the period of 14 days before the start of the research
- Use of caffeine during research
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Effects of Caffeine, CYP1A2 and ADORA2A Genotypes on Cycling Endurance Performance.
The aim of this randomized, double-blind, placebo-controlled experiment will be to assess the potential effect of the selected gene polymorphism (CYP1A2, ADORA2A) on performance after caffeine ingestion.
Read the detailed description
This randomized, double-blinded, placebo-controlled, within-subjects counter-measured study design will include 60 males and females that fall between the given age range (18-35 years).
Participants will complete five visits (~90-120 min each, 2 visits during the first week,3 visit during week 2-4) in the Laboratory at Faculty of Sports Studies of Masaryk University. All testing will take place Monday to Friday during morning hours (7-12) to minimize potential diurnal effect on sports performance. Participants will be instructed to maintain their regular diet (pre-testing meals will be replicated for all visits) and sleeping habits, avoid strenuous activity 48 hours before each visit, and abstain from caffeine one week prior to the first visit and for the duration of the data collection (4 weeks).
Sample size calculations We estimated sample size using G*Power 3.1 (Version 3.1.9.4). Effect size = 0.25, the trial would be powered to detect small but still physiologically important effect.
Alpha error = 0.025 Power (1-Beta probability) = 0.8 Number of groups = 6 - number of stratification required for genotype subgroup analysis number of measurements = 3 Sample size = based on calculation, 60 participants are required
Recruitment
Recruitment will be carried out at Masaryk University by flyers. Recruitment will also take place online through sharing on the website and social networks of the Faculty of Sports Studies of Masaryk University.
Parameters of Assessment
Physiological data will be collected by a Ph.D.-level exercise physiologist and two doctoral students.
Height will be measured to the nearest 0.1 cm using a wall-mounted stadiometer, and body weight will be measured to the nearest 0.1 kg using a digital scale with participants wearing light clothing without shoes.
Body weight value will be measured on each visit and will be used to determine 2 and 4 mg per kilogram of body mass dosages for caffeine treatments (plus a placebo dose) that will be ingested in random order (derived by research assistant and blinded to all investigators) during visits 2, 3 and 4, over the following three weeks.
Body composition will be assessed by dual-energy x-ray absorptiometry (DXA; Horizon A, Hologic Inc. Marlborough, MA) during the first week of the study.
Exercise Tests
VO2max test
Each participant will initially perform an incremental exercise test. That test will assess Vo2max and maximal workload (Wmax), which is necessary for subsequent settings. Respiratory parameters will be measured breath-by-breath using a CORTEX METALYZER 3B. Wmax will be calculated using the following equation:
Wmax= Wfinal + (t/T) x Winc. Where Wfinal is the power output of the final completed stage, t is the time achieved in the final uncompleted stage (s), T is the duration of each stage (s) and Winc is the workload increment.
Time trial
The ergometer will be set to linear mode (workload increases as the pedalling rate increases). Each participant will perform a warm-up at 1 W/kg for 5 minutes. After the warm-up participants will be instructed to complete 10 km trial as quickly as possible (with no temporal, verbal, or physiological feedback). The primary variable measured will be the time to completion of the 10 km TT. The ergometer will be set to linear mode using the following formula:
W = L x (rpm)2, where rpm is the pedalling rate and L is a linear factor dependent on the participant's Wmax. To ensure consistency across participants, the resistance on the pedals during the TT will be set so that the participants would achieve 60 % of their power output at 80 rpm using the following equation:
L = (0.60 x Wmax)/6400
A familiarization time trial will occur during the first week of a study.
Rate of perceived exertion
During the time trial protocol, information about the rate of perceived exertion will be collected. Participants will be shown a Borgs scale of Perceived Exertion to assess the subject's fatigue, This will be performed twice during the time trial protocol (5th and 9th km)
Genotyping
Buccal mucosa smears will be collected during the first week of the study. Investigators will examine known genetic variations (CYP1a2 (rs 762551), ADORA2A (rs 5451876)) that are associated with caffeine metabolism and response, to determine if these genes affect response to exercise after subjects ingest caffeine.
Caffeine intake questionnaire
Investigators will use a Caffeine intake questionnaire - revised (CCQ-R) to determine habitual caffeine intake in the week before the study starts and then each week to discover whether the participants comply with the restriction regarding caffeine, or whether they have started consuming, for example, more chocolate
Training status
At the beginning of the study, participants with one of the study investigators will complete Training and Performance Caliber: A Participant Classification Framework, based on the study by McKay et al., 2021 to determine the training status of each individual.
Statistical analysis
The statistical analysis will be carried out using IBM SPSS software. Descriptive data will be reported (VO2max/peak, body height, body weight, %body fat, lean body mass, habitual caffeine intake, training status. A t-test will determine the comparison between genotypes. Potential differences between 10 km TT will be assessed by an ANOVA with treatment as a within-participants factor and genotype as a between-participants factor.if the distribution of the data will not be normal, we will apply non-parametric equivalent of the test
Experimental procedure
Week 1
There will be three visits to the laboratories of the Faculty of Sports Studies at Masaryk University (FSpS MU):
- Participants will undergo body composition measurement (DXA) and a cheek swab for assessing selected gene variants. Data about height, weight and age will be collected (Day 1: approximate duration of visit to FSpS MU 60-90 minutes). ii. Participants will undergo maximal load testing using a cycling ergometer test and critical power testing using a cycling ergometer test (Day 2: approximate duration of visit to FSpS MU 90 minutes). iii. Participants will practice a 10-km time trial on the cycling ergometer (Day 3: approximate duration of visit to FSpS MU 60 minutes).
Weeks 2, 3, 4
Participants will undergo a 10-km time trial on the cycling ergometer. After arrival participants will be randomly assigned to one of the three conditions. They will always ingest same amount of the identical capsules (with same colour, size). After 50 minutes after the capsule ingestion, participants will start the warm-up and 60 minutes after the ingestion the TT will start. This procedure will be identical for all experimental week (2, 3 and 4). Participants may drink water ad libitum throughout the exercise test.
- Conditions
- Healthy
- Being tested
- Caffeine 2 mg, Caffeine 4 mg, Caffeine 0 mg
- Keywords
- endurance, genotype, caffeine, ergogenic effect
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Caffeine 2 mgDietary supplement
To compare exercise performance of 2 or 4 mg of caffeine per kilogram of body weight to placebo within subjects.
Caffeine 4 mgDietary supplement
To compare exercise performance of 2 or 4 mg of caffeine per kilogram of body weight to placebo within subjects.
Caffeine 0 mgDietary supplement
To compare exercise performance of 2 or 4 mg of caffeine per kilogram of body weight to placebo within subjects.
| Study group | Role | What they receive |
|---|---|---|
| Caffeine 2 mg | Active comparator | To compare exercise performance of 2 or 4 mg of caffeine per kilogram of body weight to placebo within subjects. Subjects will perform one exercise test (10 km cycling time trial). Receives: Dietary Supplement: Caffeine 2 mg |
| Caffeine 4 mg | Active comparator | To compare exercise performance of 2 or 4 mg of caffeine per kilogram of body weight to placebo within subjects. Subjects will perform one exercise test (10 km cycling time trial). Receives: Dietary Supplement: Caffeine 4 mg |
| Placebo | Placebo comparator | To compare exercise performance of 2 or 4 mg of caffeine per kilogram of body weight to placebo within subjects. Subjects will perform one exercise test (10 km cycling time trial). Receives: Dietary Supplement: Caffeine 0 mg |
What is being measured
The primary outcome is the main question the study is designed to answer.
Efficacy of caffeine to improve endurance performance (time to complete 10 km trial)
To determine if caffeine intake improves endurance performance compared to placebo. Efficacy of caffeine doses (2 mg/kg and 4 mg/kg) to shorten the time needed to complete the 10 km time trial.
Measured: 2 Hours
Secondary outcomes (1)
Caffeine ingestion and genotype interaction
To determine if different variants of selected genes affect the potential ergogenic effect of caffeine. A buccal mucosa smear will be taken to identify variants of CYP1A2 and ADORA2A genes to determine which genes/variants are associated with improvement in time trial performance after caffeine ingestion.
Measured: 1 day
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Aug 2024
- Study startAug 2024 (estimated)
- Primary completionJan 2025 (estimated)
- Study completionMar 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HealthyStudies 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
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Masaryk University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Lucie Lipková, Principal investigator, Masaryk University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06547307
- Sponsor's protocol ID
- MasarykU
- Status last verified
- Aug 2024
- First submitted
- 1 Aug 2024
- Last updated
- 9 Aug 2024
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 9 Aug 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Caffeine, CYP1A2 and ADORA2A Genotypes on Cycling Endurance Performance.
- ClinicalTrials.gov ID
- NCT06547307
- Acronym / sponsor ID
- MasarykU
- Conditions
- Healthy
- Keywords
- endurance, genotype, caffeine, ergogenic effect
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Masaryk UniversityUniversity, hospital or other
- Study start
- Aug 2024 (estimated)
- Primary completion
- Jan 2025 (estimated)
- Study completion
- Mar 2025 (estimated)
- First posted
- 9 Aug 2024 (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.
The aim of this randomized, double-blind, placebo-controlled experiment will be to assess the potential effect of the selected gene polymorphism (CYP1A2, ADORA2A) on performance after caffeine ingestion.
Detailed description
This randomized, double-blinded, placebo-controlled, within-subjects counter-measured study design will include 60 males and females that fall between the given age range (18-35 years).
Participants will complete five visits (~90-120 min each, 2 visits during the first week,3 visit during week 2-4) in the Laboratory at Faculty of Sports Studies of Masaryk University. All testing will take place Monday to Friday during morning hours (7-12) to minimize potential diurnal effect on sports performance. Participants will be instructed to maintain their regular diet (pre-testing meals will be replicated for all visits) and sleeping habits, avoid strenuous activity 48 hours before each visit, and abstain from caffeine one week prior to the first visit and for the duration of the data collection (4 weeks).
Sample size calculations We estimated sample size using G*Power 3.1 (Version 3.1.9.4). Effect size = 0.25, the trial would be powered to detect small but still physiologically important effect.
Alpha error = 0.025 Power (1-Beta probability) = 0.8 Number of groups = 6 - number of stratification required for genotype subgroup analysis number of measurements = 3 Sample size = based on calculation, 60 participants are required
Recruitment
Recruitment will be carried out at Masaryk University by flyers. Recruitment will also take place online through sharing on the website and social networks of the Faculty of Sports Studies of Masaryk University.
Parameters of Assessment
Physiological data will be collected by a Ph.D.-level exercise physiologist and two doctoral students.
Height will be measured to the nearest 0.1 cm using a wall-mounted stadiometer, and body weight will be measured to the nearest 0.1 kg using a digital scale with participants wearing light clothing without shoes.
Body weight value will be measured on each visit and will be used to determine 2 and 4 mg per kilogram of body mass dosages for caffeine treatments (plus a placebo dose) that will be ingested in random order (derived by research assistant and blinded to all investigators) during visits 2, 3 and 4, over the following three weeks.
Body composition will be assessed by dual-energy x-ray absorptiometry (DXA; Horizon A, Hologic Inc. Marlborough, MA) during the first week of the study.
Exercise Tests
VO2max test
Each participant will initially perform an incremental exercise test. That test will assess Vo2max and maximal workload (Wmax), which is necessary for subsequent settings. Respiratory parameters will be measured breath-by-breath using a CORTEX METALYZER 3B. Wmax will be calculated using the following equation:
Wmax= Wfinal + (t/T) x Winc. Where Wfinal is the power output of the final completed stage, t is the time achieved in the final uncompleted stage (s), T is the duration of each stage (s) and Winc is the workload increment.
Time trial
The ergometer will be set to linear mode (workload increases as the pedalling rate increases). Each participant will perform a warm-up at 1 W/kg for 5 minutes. After the warm-up participants will be instructed to complete 10 km trial as quickly as possible (with no temporal, verbal, or physiological feedback). The primary variable measured will be the time to completion of the 10 km TT. The ergometer will be set to linear mode using the following formula:
W = L x (rpm)2, where rpm is the pedalling rate and L is a linear factor dependent on the participant's Wmax. To ensure consistency across participants, the resistance on the pedals during the TT will be set so that the participants would achieve 60 % of their power output at 80 rpm using the following equation:
L = (0.60 x Wmax)/6400
A familiarization time trial will occur during the first week of a study.
Rate of perceived exertion
During the time trial protocol, information about the rate of perceived exertion will be collected. Participants will be shown a Borgs scale of Perceived Exertion to assess the subject's fatigue, This will be performed twice during the time trial protocol (5th and 9th km)
Genotyping
Buccal mucosa smears will be collected during the first week of the study. Investigators will examine known genetic variations (CYP1a2 (rs 762551), ADORA2A (rs 5451876)) that are associated with caffeine metabolism and response, to determine if these genes affect response to exercise after subjects ingest caffeine.
Caffeine intake questionnaire
Investigators will use a Caffeine intake questionnaire - revised (CCQ-R) to determine habitual caffeine intake in the week before the study starts and then each week to discover whether the participants comply with the restriction regarding caffeine, or whether they have started consuming, for example, more chocolate
Training status
At the beginning of the study, participants with one of the study investigators will complete Training and Performance Caliber: A Participant Classification Framework, based on the study by McKay et al., 2021 to determine the training status of each individual.
Statistical analysis
The statistical analysis will be carried out using IBM SPSS software. Descriptive data will be reported (VO2max/peak, body height, body weight, %body fat, lean body mass, habitual caffeine intake, training status. A t-test will determine the comparison between genotypes. Potential differences between 10 km TT will be assessed by an ANOVA with treatment as a within-participants factor and genotype as a between-participants factor.if the distribution of the data will not be normal, we will apply non-parametric equivalent of the test
Experimental procedure
Week 1
There will be three visits to the laboratories of the Faculty of Sports Studies at Masaryk University (FSpS MU):
- Participants will undergo body composition measurement (DXA) and a cheek swab for assessing selected gene variants. Data about height, weight and age will be collected (Day 1: approximate duration of visit to FSpS MU 60-90 minutes). ii. Participants will undergo maximal load testing using a cycling ergometer test and critical power testing using a cycling ergometer test (Day 2: approximate duration of visit to FSpS MU 90 minutes). iii. Participants will practice a 10-km time trial on the cycling ergometer (Day 3: approximate duration of visit to FSpS MU 60 minutes).
Weeks 2, 3, 4
Participants will undergo a 10-km time trial on the cycling ergometer. After arrival participants will be randomly assigned to one of the three conditions. They will always ingest same amount of the identical capsules (with same colour, size). After 50 minutes after the capsule ingestion, participants will start the warm-up and 60 minutes after the ingestion the TT will start. This procedure will be identical for all experimental week (2, 3 and 4). Participants may drink water ad libitum throughout the exercise test.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Caffeine 2 mg | Active comparator | Dietary Supplement: Caffeine 2 mgTo compare exercise performance of 2 or 4 mg of caffeine per kilogram of body weight to placebo within subjects. Subjects will perform one exercise test (10 km cycling time trial). |
| Caffeine 4 mg | Active comparator | Dietary Supplement: Caffeine 4 mgTo compare exercise performance of 2 or 4 mg of caffeine per kilogram of body weight to placebo within subjects. Subjects will perform one exercise test (10 km cycling time trial). |
| Placebo | Placebo comparator | Dietary Supplement: Caffeine 0 mgTo compare exercise performance of 2 or 4 mg of caffeine per kilogram of body weight to placebo within subjects. Subjects will perform one exercise test (10 km cycling time trial). |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- healthy person
- any training status
- within age limits
- without contraindications to perform the test on a bicycle trainer
- No contraindications to caffeine intake
Key exclusion criteria (8 listed)
- Pregnancy
- Breast feeding
- Cardiovascular disease
- Hypertension
- Liver disease in the previous two months
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 |
|---|---|---|
| Caffeine 2 mgTo compare exercise performance of 2 or 4 mg of caffeine per kilogram of body weight to placebo within subjects. | Dietary supplement | Caffeine 2 mg |
| Caffeine 4 mgTo compare exercise performance of 2 or 4 mg of caffeine per kilogram of body weight to placebo within subjects. | Dietary supplement | Caffeine 4 mg |
| Caffeine 0 mgTo compare exercise performance of 2 or 4 mg of caffeine per kilogram of body weight to placebo within subjects. | Dietary supplement | Placebo |
Primary outcome
Efficacy of caffeine to improve endurance performance (time to complete 10 km trial)
Time frame: 2 Hours
To determine if caffeine intake improves endurance performance compared to placebo. Efficacy of caffeine doses (2 mg/kg and 4 mg/kg) to shorten the time needed to complete the 10 km time trial.
1 secondary outcome
Caffeine ingestion and genotype interaction
Time frame: 1 day
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Aug 2024.
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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.
Lucie Lipková principal investigator
Masaryk University
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 2 mg, Caffeine 4 mg and Caffeine 0 mg in people with Healthy, run by Masaryk University at 1 site in Czechia.
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 5 inclusion and 8 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: status not confirmed, as of the sponsor's last update on 9 Aug 2024. 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 Czechia. 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?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Dominik Puda (+420724587249, dominik.puda@fsps.muni.cz), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Efficacy of caffeine to improve endurance performance (time to complete 10 km trial) (time frame: 2 Hours). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 Aug 2024.