CaffeinePhase 1/2NCT07469852
Effects of Caffeine Ingestion on Morning Cognitive and 4-km Time Trial Performance in Males
A Phase 1/2 study testing Caffeine (300 mg) and No Pill in people with Caffeine and Placebo - Control, run by Liverpool John Moores University at 1 site in United Kingdom.
Trial summary
Athletes often compete in the morning when they are biologically weaker; normally in competition heats or quarterfinals to qualify for the finals scheduled in the evening. Some athletes may even choose to perform at submaximal levels in these qualifying rounds, especially when they are expected to perform multiple… Read more about this study
- Who is it for?
- Ages 18 to 35 yearsHealthy volunteers can take part
- Conditions the study is for
- Caffeine, Placebo - Control, No Pill
- What is being tested?
- Caffeine (300 mg) and No Pill
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 15 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 12 Jan 2026to 25 Mar 2026
- Phase
- Phase 1/2
- Are there results?
- Not yet: the study is under way
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 adults
- 18-35 years old
- Injury-free
- ≥ 2 years of weight/strength training experience
- Not receiving any pharmacological treatment (including non-steroidal anti-inflammatory drugs, NSAIDs) throughout the study period
- Low habitual caffeine consumers (≤ 150mg per day)
- No preference to training regarding time-of-day
Who cannot join
- Depressed mood (from the Beck depression inventory)
- Poor sleep quality (a Pittsburgh sleep quality index global score >5
- Recent shift work or travel across multiple time-zones
- Extreme chronotype (assessed via the Composite Morningness Questionnaire
- Risk factors and/ or symptoms of cardiovascular disease.
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site
Tom Reilly Building (LJMU)
Liverpool, Merseyside, L3 3AF
About this study
Official title: Effects of Caffeine Ingestion on Morning Cognitive and 4-km Time Trial Performance in Males. Where a Standardized Approach Has Been Employed
Athletes often compete in the morning when they are biologically weaker; normally in competition heats or quarterfinals to qualify for the finals scheduled in the evening. Some athletes may even choose to perform at submaximal levels in these qualifying rounds, especially when they are expected to perform multiple times in the same day (such as weightlifting at the Olympic Games). Gross muscular performance such as power output or force production is greater in the evening than the morning (~3-14% variation). Similarly, time-trial performance and repeated sprint performance (RSP; a good measure of performance in team sport) is ~3 and 5 % greater in the evening than the morning.
The reason for this daily variation in performance is attributed to central factors (such as the body clock), as well as motivational and peripheral factors, including higher core and muscle temperatures in the evening compared to the morning. The body clock located within the anterior hypothalamus consists of a group of neurons known as suprachiasmatic nuclei, which are responsible for controlling the rhythm of core temperature.
Read more
The most efficient nutritional ergogenic is caffeine. Recently caffeine has been investigated to reduce the negative influence of diurnal variations on repeated-sprint ability test (10 × 6 s cycle sprints, with 30 s of rest) at 60 min after ingestion of either 5 mg·kg-1 or placebo. Lopes-Silva et al. (2019) reported that caffeine supplementation did not prevent the reduction in performance in the morning. However, placebo effect can be 3-5% and hence the use of a No-pill condition would ensure that any placebo effect is accounted for and that the true potential effect of caffeine can be established.
To the best of our knowledge, no study has yet investigated caffeine (CAFF), NoPill (NOPILL) or Placebo (PLAC) effects on cognitive and 4-km time-trial (TT) performance. As a diurnal variation in 4-km TT has been widely reported in a similar population. The aim of the present study is to investigate if ingesting caffeine on the day of the morning test, to improve performance.
- Conditions
- Caffeine, Placebo - Control, No Pill
- Being tested
- Caffeine (300 mg), Placebo, No Pill
- Keywords
- Caffine, morning cognitive performance, morning 4-km time-trial performance
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Caffeine (300 mg)Drug
300mg of of caffeine anhydrous in 3 capsules similar to PLACEBO in size and weight
PlaceboOther
3 capsules of PLACEBO similar to caffeine condition in size and weight
No PillOther
No capsules were given
| Study group | Role | What they receive |
|---|---|---|
| Group 1 | Experimental | 1) NoPill, 2) PLAC, 3) Caffeine (300 mg) Receives: Drug: Caffeine (300 mg); Other: Placebo; Other: No Pill |
| Group 2 | Experimental | 1) PLAC, 2) Caffeine (300 mg), 3) NoPill, Receives: Drug: Caffeine (300 mg); Other: Placebo; Other: No Pill |
| Group 3 | Experimental | 1) Caffeine (300 mg) 2) NoPill, 3) PLAC Receives: Drug: Caffeine (300 mg); Other: Placebo; Other: No Pill |
What is being measured
The primary outcome is the main question the study is designed to answer.
Morning 4-km time-trial finishing time
4-km cycling time-trial (Watbike Pro, Nottingham UK) finishing time in minute and seconds. ~ 4-6 minutes.
Measured: From enrolment to last experimental session (~4 weeks)
4-km cycling time-trial split times every 1 km.
4-km cycling time-trial (Watbike Pro, Nottingham UK) split times (in minutes and seconds) every 1 km.
Measured: From familiarisation to the final experimental session (~4 weeks)
Heart rate every 1-km
Heart rate measured every 1-km during the 4-km time-trial, using a heart rate monitor.
Measured: From familiarisation to the final experimental session (~4 weeks)
Rating of perceived exertion every 1-km
Rating of perceived exertion every 1-km for the 4-km time-trail. Measured on a 6 (no exertion) to 20 (maximal exertion) scale. Takes ~1 s.
Measured: From familiarisation to the final experimental session (~4 weeks)
Perceived pacing taken at 2 and 4 km
Perceived pacing taken at 2 and 4 km of the 4-km time trial. The scale is a 10 cm visual analogue scale where -5 represents pacing to slow to complete the 2 km as fast as possible, zero = optimal pacing and +5 went to fast. Takes ~1 s to answer.
Measured: From familiarisation to the final experimental session (~4 weeks)
Morning Trail Making Test time to completion in seconds (TMT; parts A and B)
To assess the effect of 300 mg caffeine (CAFF) vs placebo (PLAC) vs no-pill (NoPill) on morning Trail Making Test time to completion in seconds (TMT; parts A and B). In part A the circles are numbered 1-25, and the participant is instructed to draw lines to connect the numbers in ascending order. In part B, the circles include both numbers (1-13) and letters (A-L) and the participant is instructed to draw lines to connect the circles in ascending pattern but with the added task of alternating between numbers and letters (i.e., 1-A-2-B-3-C etc.). In both parts the participant is instructed to connect to the circles as fast as possible, without lifting the pencil from the paper. If an error is made, this is pointed out immediately and the participant is allowed to correct it. During the test, time to completion is measured, with a higher time indicative of the greater impairment.
Measured: From enrolment to last experimental session (4 weeks)
Morning Rey Auditory Verbal Learning Test
Rey Auditory Verbal Learning Test: The RAVLT is a neuropsychological assessment designed to evaluate verbal memory. The test is designed as a list-learning paradigm in which the volunteer hears a list of 15 nouns and is asked to recall as many words from the list as possible. The number correct and the number that were given by the participant but not on the list (intrusions) are noted. This process is re-peated 4 more times. The process is repeated but with a second interference list (List B) is presented in the same manner, and the participant is asked to recall as many words as possible from List B and scoring recorded. . After the interference trial, the participant is immediately asked to recall the words from List A, which they heard five times previously and the number of correct words and intrusions are recorded. RAVTL total number, number of dis-tractions and retention are recorded and analysed.
Measured: From familiarisation to the final experimental session (~4 weeks)
Morning Stroop word-colour interference test
Stroop word-colour interference test. The participants were asked to read out their responses to words or colours for 45 s as quickly as possible and to leave no errors uncorrected. This was filmed and the number of errors and total amount completed was recorded and analysed. The first sheet had text (red, blue, yellow, black and green) in black ink (naming word test, W). The second sheet had blocks of colour corresponding to the text on the first sheet (naming colour test, C). With the third sheet, the participants had to read out the word (which was coloured differently to the word, e.g., the word was yellow and the colour red, referred to as the naming colour of word test, CW) and for the fourth sheet, the participants had to read out the colon (which was wrongly named, e.g., the colour was yellow but the word was red, referred to as the naming of word not colour test, WC). In this fourth sheet, the words were printed in the reverse order to the third sheet.
Measured: From familiarisation to the final experimental session (~4 weeks)
Secondary outcomes (13)
Rectal temperature @rest and after warm-up
Rectal temperature by a soft flexible rectal probe (mini-thermistor, Grant Instruments, Shepreth, UK) approximately 10 cm beyond the external anal sphincter. Duration in each session no longer than 35 mins.
Measured: From enrolment to last experimental session (4 weeks)
Blood lactate @ rest, pre TT and after
Blood lactate (finger tip) values will betaken @ rest, pre TT and after
Measured: From enrolment to last experimental session (4 weeks)
Mean skin temperature (Tsk)
Mean Skin temperature (Tsk) was assessed simultaneously by skin thermistors (Grant Instruments, Squirrel 2010 series, Shepreth, UK), which were placed at four locations on the left side of the body (chest [ch], forearm [f], thigh [th] and calf [ca]). Duration in each session no longer than 35 mins.
Mean Tsk was calculated as follows:
Tsk = (0.34 x Tch) + (0.33 x Tth) + (0.18 x Tca) + (0.15 x Tf)
Measured: From familiarisation to the final experimental session (~4 weeks)
The mean body temperature (Tmb)
The mean body temperature (Tmb) was calculated using skin thermistors from 4 skin sites on the left side of the body (chest [ch], forearm [f], thigh [th] and calf [ca]). : Tmb = (0.64 x Tr) + (0.36 x Tsk)
Measured: From familiarisation to the final experimental session (~4 weeks).
Morning profile of mood states questionnaire
Morning profile of mood states questionnaire (POMS; Version 32) for moods: vigour, tension, calmness, happiness, confusion, depression and fatigue on a visual analogue scale (0=not at all and 4 = extremely). Each mood is the addition of scores for the 4 questions associated with the mood. ~ 60 s each task.
Measured: From familiarisation to the final experimental session (~4 weeks)
Sleep questions from the Liverpool Jet lag Questionnaire
Sleep questions from the Liverpool Jet lag Questionnaire: get to sleep, how well slept, waking time and alertness after waking. Measured on a -5 (later or worst) to +5 scale (more or earlier) where ZERO is compared to normal.
Measured: From familiarisation to the final experimental session (~4 weeks)
7-day food diary
7-day food diary that was analyzed using Nutritics® analysis software by a SENr registered Sports and Exercise Nutritionist. Data is presented in macro-nutrients and micro-nutrient diet (mg or g).
Measured: Baseline
Habitual caffeine consumption
Habitual caffeine consumption was assessed using the caffeine consumption questionnaire (CCQ), where caffeine intake was assessed in the morning, afternoon, evening and night. Total daily intake was expressed in mg.
Measured: Baseline
Self-reported 2-week training diary
No preference to training regarding time-of-day by a weekly self-reported 2-week training diary for type of exercise, duration, intensity and time of day. With time of day of exercise preference recorded.
Measured: Baseline
Chronotype
Extreme chronotype (assessed via the Composite Morningness Questionnaire) to assess morning, intermediate and evening types. Where Evening type scores 22 and less, Intermediate type 22-43 and Morning type 44 and above.
Measured: Baseline
Poor sleep quality
Poor sleep quality (as indicated by the Pittsburgh sleep quality index global score >5).
Measured: At the start of the study as part of exclusion criteria
Depressed mood
Depressed mood severity from the Beck depression inventory (BDI).21 questions were answered (with 4 answers, 0= I do not feel and 3 = I am so..). The values summated to scores where 0-9 is minimal depression, 10-18 mild and 19-29 moderate depression. 30-63 sever depression. This takes 60 s to complete.
Measured: Baseline
Caffeine withdrawal symptoms score
Caffeine withdrawal symptoms (total score) assesses caffeine withdrawal symptoms. Participants were asked to rate each of the 32 questions in terms of how they were feeling at that moment on a 5-pt. scale from 0 (not at all) to 4 (extremely). Eight of the items are positively worded (e.g., energetic) and were reversed scored prior to analyses. At start and during the protocol.]
Measured: From familiarisation to the final experimental session (~4 weeks).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Mar 2026
- Study start12 Jan 2026
- Primary completion25 Mar 2026 (estimated)
- Study completion25 Mar 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for CaffeineStudies 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 1/2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Double blinded repeated measures counterbalanced design with three conditions
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 15 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Liverpool John Moores University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, spsbedwa@ljmu.ac.uk, Liverpool John Moores University
- Investigators
- Ben J Edwards, PHD, Principal investigator, Liverpool John Moores University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07469852
- Sponsor's protocol ID
- 251121LJMUSPSREC77
- Status last verified
- Mar 2026
- First submitted
- 25 Feb 2026
- Last updated
- 13 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: IPD unavailable due to privacy or ethical restrictions
Publications
Mitchell PJ, Redman JR. Effects of caffeine, time of day and user history on study-related performance. Psychopharmacology (Berl). 1992;109(1-2):121-6. doi: 10.1007/BF02245489.
PubMed 1365645Munnilari M, Bommasamudram T, Easow J, Tod D, Varamenti E, Edwards BJ, Ravindrakumar A, Gallagher C, Pullinger SA. Diurnal variation in variables related to cognitive performance: a systematic review. Sleep Breath. 2024 Mar;28(1):495-510. doi: 10.1007/s11325-023-02895-0. Epub 2023 Aug 17.
PubMed 37589927Drust B, Waterhouse J, Atkinson G, Edwards B, Reilly T. Circadian rhythms in sports performance--an update. Chronobiol Int. 2005;22(1):21-44. doi: 10.1081/cbi-200041039.
PubMed 15865319Walsh NP, Halson SL, Sargent C, Roach GD, Nedelec M, Gupta L, Leeder J, Fullagar HH, Coutts AJ, Edwards BJ, Pullinger SA, Robertson CM, Burniston JG, Lastella M, Le Meur Y, Hausswirth C, Bender AM, Grandner MA, Samuels CH. Sleep and the athlete: narrative review and 2021 expert consensus recommendations. Br J Sports Med. 2020 Nov 3:bjsports-2020-102025. doi: 10.1136/bjsports-2020-102025. Online ahead of print.
PubMed 33144349
Study at a glance
From the registry record, last updated by the sponsor on 13 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Caffeine Ingestion on Morning Cognitive and 4-km Time Trial Performance in Males. Where a Standardized Approach Has Been Employed
- ClinicalTrials.gov ID
- NCT07469852
- Acronym / sponsor ID
- 251121LJMUSPSREC77
- Conditions
- Caffeine, Placebo - Control, No Pill
- Keywords
- Caffine, morning cognitive performance, morning 4-km time-trial performance
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 15 participants (estimated)
- Lead sponsor
- Liverpool John Moores UniversityUniversity, hospital or other
- Study start
- 12 Jan 2026 (actual)
- Primary completion
- 25 Mar 2026 (estimated)
- Study completion
- 25 Mar 2026 (estimated)
- First posted
- 13 Mar 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.
Athletes often compete in the morning when they are biologically weaker; normally in competition heats or quarterfinals to qualify for the finals scheduled in the evening. Some athletes may even choose to perform at submaximal levels in these qualifying rounds, especially when they are expected to perform multiple times in the same day (such as weightlifting at the Olympic Games). Gross muscular performance such as power output or force production is greater in the evening than the morning (~3-14% variation). Similarly, time-trial performance and repeated sprint performance (RSP; a good measure of performance in team sport) is ~3 and 5 % greater in the evening than the morning.
The reason for this daily variation in performance is attributed to central factors (such as the body clock), as well as motivational and peripheral factors, including higher core and muscle temperatures in the evening compared to the morning. The body clock located within the anterior hypothalamus consists of a group of neurons known as suprachiasmatic nuclei, which are responsible for controlling the rhythm of core temperature.
The most efficient nutritional ergogenic is caffeine. Recently caffeine has been investigated to reduce the negative influence of diurnal variations on repeated-sprint ability test (10 × 6 s cycle sprints, with 30 s of rest) at 60 min after ingestion of either 5 mg·kg-1 or placebo. Lopes-Silva et al. (2019) reported that caffeine supplementation did not prevent the reduction in performance in the morning. However, placebo effect can be 3-5% and hence the use of a No-pill condition would ensure that any placebo effect is accounted for and that the true potential effect of caffeine can be established.
To the best of our knowledge, no study has yet investigated caffeine (CAFF), NoPill (NOPILL) or Placebo (PLAC) effects on cognitive and 4-km time-trial (TT) performance. As a diurnal variation in 4-km TT has been widely reported in a similar population. The aim of the present study is to investigate if ingesting caffeine on the day of the morning test, to improve performance.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, investigator)
- Number of arms
- 3
- Model description
- Double blinded repeated measures counterbalanced design with three conditions
| Arm | Type | Receives |
|---|---|---|
| Group 1 | Experimental | Drug: Caffeine (300 mg), Other: Placebo, Other: No Pill1) NoPill, 2) PLAC, 3) Caffeine (300 mg) |
| Group 2 | Experimental | Drug: Caffeine (300 mg), Other: Placebo, Other: No Pill1) PLAC, 2) Caffeine (300 mg), 3) NoPill, |
| Group 3 | Experimental | Drug: Caffeine (300 mg), Other: Placebo, Other: No Pill1) Caffeine (300 mg) 2) NoPill, 3) PLAC |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (7 listed)
- Healthy adults
- 18-35 years old
- Injury-free
- ≥ 2 years of weight/strength training experience
- Not receiving any pharmacological treatment (including non-steroidal anti-inflammatory drugs, NSAIDs) throughout the study period
Key exclusion criteria (5 listed)
- Depressed mood (from the Beck depression inventory)
- Poor sleep quality (a Pittsburgh sleep quality index global score >5
- Recent shift work or travel across multiple time-zones
- Extreme chronotype (assessed via the Composite Morningness Questionnaire
- Risk factors and/ or symptoms of cardiovascular disease.
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 (300 mg)300mg of of caffeine anhydrous in 3 capsules similar to PLACEBO in size and weight | Drug | Group 1, Group 2, Group 3 |
| Placebo3 capsules of PLACEBO similar to caffeine condition in size and weight | Other | Group 1, Group 2, Group 3 |
| No PillNo capsules were given | Other | Group 1, Group 2, Group 3 |
Primary outcome
Morning 4-km time-trial finishing time
Time frame: From enrolment to last experimental session (~4 weeks)
4-km cycling time-trial (Watbike Pro, Nottingham UK) finishing time in minute and seconds. ~ 4-6 minutes.
4-km cycling time-trial split times every 1 km.
Time frame: From familiarisation to the final experimental session (~4 weeks)
4-km cycling time-trial (Watbike Pro, Nottingham UK) split times (in minutes and seconds) every 1 km.
Heart rate every 1-km
Time frame: From familiarisation to the final experimental session (~4 weeks)
Heart rate measured every 1-km during the 4-km time-trial, using a heart rate monitor.
Rating of perceived exertion every 1-km
Time frame: From familiarisation to the final experimental session (~4 weeks)
Rating of perceived exertion every 1-km for the 4-km time-trail. Measured on a 6 (no exertion) to 20 (maximal exertion) scale. Takes ~1 s.
Perceived pacing taken at 2 and 4 km
Time frame: From familiarisation to the final experimental session (~4 weeks)
Perceived pacing taken at 2 and 4 km of the 4-km time trial. The scale is a 10 cm visual analogue scale where -5 represents pacing to slow to complete the 2 km as fast as possible, zero = optimal pacing and +5 went to fast. Takes ~1 s to answer.
Morning Trail Making Test time to completion in seconds (TMT; parts A and B)
Time frame: From enrolment to last experimental session (4 weeks)
To assess the effect of 300 mg caffeine (CAFF) vs placebo (PLAC) vs no-pill (NoPill) on morning Trail Making Test time to completion in seconds (TMT; parts A and B). In part A the circles are numbered 1-25, and the participant is instructed to draw lines to connect the numbers in ascending order. In part B, the circles include both numbers (1-13) and letters (A-L) and the participant is instructed to draw lines to connect the circles in ascending pattern but with the added task of alternating between numbers and letters (i.e., 1-A-2-B-3-C etc.). In both parts the participant is instructed to connect to the circles as fast as possible, without lifting the pencil from the paper. If an error is made, this is pointed out immediately and the participant is allowed to correct it. During the test, time to completion is measured, with a higher time indicative of the greater impairment.
Morning Rey Auditory Verbal Learning Test
Time frame: From familiarisation to the final experimental session (~4 weeks)
Rey Auditory Verbal Learning Test: The RAVLT is a neuropsychological assessment designed to evaluate verbal memory. The test is designed as a list-learning paradigm in which the volunteer hears a list of 15 nouns and is asked to recall as many words from the list as possible. The number correct and the number that were given by the participant but not on the list (intrusions) are noted. This process is re-peated 4 more times. The process is repeated but with a second interference list (List B) is presented in the same manner, and the participant is asked to recall as many words as possible from List B and scoring recorded. . After the interference trial, the participant is immediately asked to recall the words from List A, which they heard five times previously and the number of correct words and intrusions are recorded. RAVTL total number, number of dis-tractions and retention are recorded and analysed.
Morning Stroop word-colour interference test
Time frame: From familiarisation to the final experimental session (~4 weeks)
Stroop word-colour interference test. The participants were asked to read out their responses to words or colours for 45 s as quickly as possible and to leave no errors uncorrected. This was filmed and the number of errors and total amount completed was recorded and analysed. The first sheet had text (red, blue, yellow, black and green) in black ink (naming word test, W). The second sheet had blocks of colour corresponding to the text on the first sheet (naming colour test, C). With the third sheet, the participants had to read out the word (which was coloured differently to the word, e.g., the word was yellow and the colour red, referred to as the naming colour of word test, CW) and for the fourth sheet, the participants had to read out the colon (which was wrongly named, e.g., the colour was yellow but the word was red, referred to as the naming of word not colour test, WC). In this fourth sheet, the words were printed in the reverse order to the third sheet.
13 secondary outcomes
Rectal temperature @rest and after warm-up
Time frame: From enrolment to last experimental session (4 weeks)
Blood lactate @ rest, pre TT and after
Time frame: From enrolment to last experimental session (4 weeks)
Mean skin temperature (Tsk)
Time frame: From familiarisation to the final experimental session (~4 weeks)
The mean body temperature (Tmb)
Time frame: From familiarisation to the final experimental session (~4 weeks).
Morning profile of mood states questionnaire
Time frame: From familiarisation to the final experimental session (~4 weeks)
Sleep questions from the Liverpool Jet lag Questionnaire
Time frame: From familiarisation to the final experimental session (~4 weeks)
7-day food diary
Time frame: Baseline
Habitual caffeine consumption
Time frame: Baseline
Self-reported 2-week training diary
Time frame: Baseline
Chronotype
Time frame: Baseline
Poor sleep quality
Time frame: At the start of the study as part of exclusion criteria
Depressed mood
Time frame: Baseline
Caffeine withdrawal symptoms score
Time frame: From familiarisation to the final experimental session (~4 weeks).
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Mar 2026.
- Background: PubMed 1365645Mitchell PJ, Redman JR. Effects of caffeine, time of day and user history on study-related performance. Psychopharmacology (Berl). 1992;109(1-2):121-6. doi: 10.1007/BF02245489.
- Background: PubMed 37589927Munnilari M, Bommasamudram T, Easow J, Tod D, Varamenti E, Edwards BJ, Ravindrakumar A, Gallagher C, Pullinger SA. Diurnal variation in variables related to cognitive performance: a systematic review. Sleep Breath. 2024 Mar;28(1):495-510. doi: 10.1007/s11325-023-02895-0. Epub 2023 Aug 17.
- Background: PubMed 15865319Drust B, Waterhouse J, Atkinson G, Edwards B, Reilly T. Circadian rhythms in sports performance--an update. Chronobiol Int. 2005;22(1):21-44. doi: 10.1081/cbi-200041039.
- Background: PubMed 33144349Walsh NP, Halson SL, Sargent C, Roach GD, Nedelec M, Gupta L, Leeder J, Fullagar HH, Coutts AJ, Edwards BJ, Pullinger SA, Robertson CM, Burniston JG, Lastella M, Le Meur Y, Hausswirth C, Bender AM, Grandner MA, Samuels CH. Sleep and the athlete: narrative review and 2021 expert consensus recommendations. Br J Sports Med. 2020 Nov 3:bjsports-2020-102025. doi: 10.1136/bjsports-2020-102025. Online ahead of print.
- Individual participant dataSharing planned: No. IPD unavailable due to privacy or ethical restrictions
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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.
Ben J Edwards, PHD principal investigator
Liverpool John Moores University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing Caffeine (300 mg) and No Pill in people with Caffeine and Placebo - Control, run by Liverpool John Moores University at 1 site in United Kingdom.
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 7 inclusion and 5 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: under way, not looking for participants, as of the sponsor's last update on 13 Mar 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 United Kingdom. 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. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
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?
Morning 4-km time-trial finishing time (time frame: From enrolment to last experimental session (~4 weeks)). The study lists 8 primary outcomes in all. 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 NCT07469852, which also lists 4 linked publications.
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 13 Mar 2026.