Effects of Caffeine Ingestion on Morning Cognitive and 4-km Time Trial Performance in Males

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.

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 Overview

• Status: Active, not recruiting
• Conditions: Caffeine; Placebo - Control; No Pill
• Intervention / Treatment: Other: No Pill; Drug: Caffeine (300 mg); Other: Placebo

• Study Type: Interventional
• Enrollment (Estimated): 15
• Phase: Phase 2; Phase 1

Contacts and Locations

Study Locations

• United Kingdom
  • Merseyside
    • Liverpool, Merseyside, United Kingdom, L3 3AF
      • Tom Reilly Building (LJMU)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• 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

Exclusion Criteria:

• 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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Group 1; 1) NoPill, 2) PLAC, 3) Caffeine (300 mg)	Other: No Pill; No capsules were given; Drug: Caffeine (300 mg); 300mg of of caffeine anhydrous in 3 capsules similar to PLACEBO in size and weight; Other: Placebo; 3 capsules of PLACEBO similar to caffeine condition in size and weight
Experimental: Group 3; 1) Caffeine (300 mg) 2) NoPill, 3) PLAC	Other: No Pill; No capsules were given; Drug: Caffeine (300 mg); 300mg of of caffeine anhydrous in 3 capsules similar to PLACEBO in size and weight; Other: Placebo; 3 capsules of PLACEBO similar to caffeine condition in size and weight
Experimental: Group 2; 1) PLAC, 2) Caffeine (300 mg), 3) NoPill,	Other: No Pill; No capsules were given; Drug: Caffeine (300 mg); 300mg of of caffeine anhydrous in 3 capsules similar to PLACEBO in size and weight; Other: Placebo; 3 capsules of PLACEBO similar to caffeine condition in size and weight

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	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.	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.	From enrolment to last experimental session (4 weeks)
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.	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.	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.	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.	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.	From familiarisation to the final experimental session (~4 weeks)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	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.	From familiarisation to the final experimental session (~4 weeks)
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.	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.	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.	Baseline
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.	Baseline
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.	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	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)	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)	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).	Baseline
Poor sleep quality	Poor sleep quality (as indicated by the Pittsburgh sleep quality index global score >5).	At the start of the study as part of exclusion criteria
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.]	From familiarisation to the final experimental session (~4 weeks).

Collaborators and Investigators

• Sponsor: Liverpool John Moores University
• Investigators: Principal Investigator: Ben J Edwards, PHD, Liverpool John Moores University

Publications and helpful links

General Publications

• Walsh 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.
• Drust 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.
• Munnilari 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.
• 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.

Study record dates

Study Major Dates

• Study Start (Actual): January 12, 2026
• Primary Completion (Estimated): March 25, 2026
• Study Completion (Estimated): March 25, 2026

Study Registration Dates

• First Submitted: February 25, 2026
• First Submitted That Met QC Criteria: March 9, 2026
• First Posted (Actual): March 13, 2026

Study Record Updates

• Last Update Posted (Actual): March 13, 2026
• Last Update Submitted That Met QC Criteria: March 9, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Caffine; morning cognitive performance; morning 4-km time-trial performance
• Additional Relevant MeSH Terms: Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Alkaloids; Purinones; Purines; Xanthines; Caffeine
• Other Study ID Numbers: 251121LJMUSPSREC77

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: IPD unavailable due to privacy or ethical restrictions

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No