Effects of Caffeine Ingestion on Morning Cognitive and Muscle Strength Measures in Males

NCT07466628 | Completed Phase 4

• 1 other identifier: 08/SPS/030
• Study Type: interventional
• Target: 15
• Locations: 1 country
• Sites: 1

Brief Summary

Tournament scheduling and environmental factors often require athletes to compete in the morning. Equally due to time constraints, athletes may choose to train in the morning. However, muscle power output and force production, are higher in the mid-afternoon or early evening whatever the method used, the muscle groups tested or the mode and speed of contraction. Cognitive performance is another essential determinant for many athletes that has been shown to be time-of-day and variable dependent. Considered as multifactorial, it includes many different components related to attention, accuracy, consistency, reaction time, vigilance, decision making and executive functions. Executive functions notably include the ability to plan and coordinate considered action while updating it with inhibition processes of distractions to focus attention on the relevant information. Subjective negative mood states (fatigue) and motivation levels, which are essential elements for tasks requiring higher cognitive function are poorer in the morning than the evening. Caffeine (1,3,7-trimethylxanthine) is amongst the most extensively researched ergogenic supplements within the field of sport, aimed at enhancing alertness, concentration, cognitive and physical performance. Caffeine's primary mechanism of action in the brain is the blockage of adenosine receptors, which play a central role in the regulation of sleep-wake-cycle by increasing sleep pressure throughout the activity phase. It is thought that by blocking these receptors, caffeine counteracts natural tiredness, improving attention, focus and improving overall cognitive performance. One of the few studies to investigate caffeine effects on morning cognitive performance report-ed an improvement in a simple search task 2.5 % in undergraduate students, when 4 mg.kg-1 body mass of caffeine was consumed 1-h before a 07:00 h experimental session versus Placebo. Unlike the sparce research investigating cognitive effects of morning caffeine ingestion, its effects on muscle performance have been demonstrated elsewhere. Caffeine (3 mg.kg-1 body mass) ingested 60-min before exercise increased dynamic strength and power output of upper and lower muscle groups in the morning (10:00 h) in resistance-trained men, with 4.6-5.3% improvement compared to placebo. Similarly, caffeine (3 mg.kg-1 body mass) ingested 60-min before exercise at 09:00 h improved muscular strength/power at moderate-to-high loads (75-90% 1RM) and endurance performance (65% 1RM) in the back squat while counteracting morning declines at light-load (25% 1RM) for both back squat and bench press without altering electrical activity. These benefits are likely due to increased neural activation, enhanced calcium release in muscles, and a reduction in the perception of effort during exercise, making it easier to exert maximal effort. The observation of caffeine's ability to improve morning cognitive and physical performance, may be obscured by lack of rigor and standardization in the method employed (such as timing of the ingestion and dose chosen). Many studies do not report any control condition that consider a placebo effect (no pill, familiarization of the tests to be conducted, recruit sample size based on a power calculation and no standardization of participants habitual caffeine use (low, medium or high caffeine daily users). In addition, studies have often failed to control important factors such as chronotype, time-of year, or time-of-day and participants' quality of sleep. Which specifically relates to investigations of chronobiological nature and other considerations. Objectives: To assess the effect of 300 mg caffeine (CAFF) vs placebo (PLAC) vs no-pill (NoPill) on morning a) strength and power output measured via the Biodex Isometric MVC as well as the Muscle Lab force-velocity linear encoder \[such as peak force (PF), % muscle activation, average power (AP), average velocity (AV), peak velocity (PV), mean propulsive velocity (MPV), rate of development of velocity (RDV), displacement (D) and time-to-peak velocity (tPV)\] and b) cognitive performance (including tasks of attention, memory and executive function). A population of low daily users \< 150 mg was chosen, to reduce effects of caffeine withdrawal symptoms on the non-caffeine condition on performance. As well as maximize caffeine effects at the 300 mg dose administered.

Conditions

Caffine; Placebo - Control; No Pill

Keywords

Caffine; morning cognitive performance; morning strength performance

Outcome Measures

Primary Outcomes (8)

• Morning peak force production (N) measured via the Biodex Isometric MVC, with and without percutaneous stimulation.

  To assess the effect of 300 mg caffeine (CAFF) vs placebo (PLAC) vs no-pill (NoPill) on morning peak force production (N) measured via the Biodex Isometric MVC, with and without percutaneous stimulation.

  From familiarisation to the final experimental session (~4 weeks)

• Muscle Lab force-velocity linear encoder morning average power (AP, W), for bench press and back squat at 40, 60 and 80% 1RM (maximum repetition).

  To assess the effect of 300 mg caffeine (CAFF) vs placebo (PLAC) vs no-pill (NoPill) on Muscle Lab force-velocity linear encoder morning average power (AP, W), for bench press and back squat at 40, 60 and 80% 1RM (maximum repetition). The individual's own body mass was factored into the back squat exercise, as this is a whole-body movement, but not into the bench press. The MuscleLab force-velocity linear encoder (Muscle Lab, Ergotest version 4010, Norway) was attached to an Eleiko Olympic bar (20 kg) which was set upon rests on a standard squat rack, safety arms were set so that the participant achieved ≤90° knee flexion position (settings measured and recorded during the familiarization process). From this position, the participant was instructed to drive the bar upwards as forcefully as possible; the value recorded during the test was for the concentric phase of the action only.

  From familiarisation to the final experimental session (~4 weeks)

• Morning average velocity (AV, m/s), for bench press and back squat at 40, 60 and 80% 1RM (maximum repetition).

  To assess the effect of 300 mg caffeine (CAFF) vs placebo (PLAC) vs no-pill (NoPill) on Muscle Lab force-velocity linear encoder morning average velocity (AV, m/s), for bench press and back squat at 40, 60 and 80% 1RM (maximum repetition). The individual's own body mass was factored into the back squat exercise, as this is a whole-body movement, but not into the bench press. The MuscleLab force-velocity linear encoder (Muscle Lab, Ergotest version 4010, Norway) was attached to an Eleiko Olympic bar (20 kg) which was set upon rests on a standard squat rack, safety arms were set so that the participant achieved ≤90° knee flexion position (settings measured and recorded during the familiarization process). From this position, the participant was instructed to drive the bar upwards as forcefully as possible; the value recorded during the test was for the concentric phase of the action only.

  From familiarisation to the final experimental session (~4 weeks)

• Morning peak velocity (PV, m/s), for bench press and back squat at 40, 60 and 80% 1RM (maximum repetition).

  To assess the effect of 300 mg caffeine (CAFF) vs placebo (PLAC) vs no-pill (NoPill) on Muscle Lab force-velocity linear encoder morning peak velocity (PV, m/s), for bench press and back squat at 40, 60 and 80% 1RM (maximum repetition). The individual's own body mass was factored into the back squat exercise, as this is a whole-body movement, but not into the bench press. The MuscleLab force-velocity linear encoder (Muscle Lab, Ergotest version 4010, Norway) was attached to an Eleiko Olympic bar (20 kg) which was set upon rests on a standard squat rack, safety arms were set so that the participant achieved ≤90° knee flexion position (settings measured and recorded during the familiarization process). From this position, the participant was instructed to drive the bar upwards as forcefully as possible; the value recorded during the test was for the concentric phase of the action only.

  From familiarisation to the final experimental session (~4 weeks)

• Morning mean propulsive velocity (MPV, m/s), for bench press and back squat at 40, 60 and 80% 1RM (maximum repetition).

  To assess the effect of 300 mg caffeine (CAFF) vs placebo (PLAC) vs no-pill (NoPill) on Muscle Lab force-velocity linear encoder morning mean propulsive velocity (MPV, m/s), for bench press and back squat at 40, 60 and 80% 1RM (maximum repetition). The individual's own body mass was factored into the back squat exercise, as this is a whole-body movement, but not into the bench press. The MuscleLab force-velocity linear encoder (Muscle Lab, Ergotest version 4010, Norway) was attached to an Eleiko Olympic bar (20 kg) which was set upon rests on a standard squat rack, safety arms were set so that the participant achieved ≤90° knee flexion position (settings measured and recorded during the familiarization process). From this position, the participant was instructed to drive the bar upwards as forcefully as possible; the value recorded during the test was for the concentric phase of the action only.

  From familiarisation to the final experimental session (~4 weeks)

• Morning rate of development of velocity (RDV), for bench press and back squat at 40, 60 and 80% 1RM (maximum repetition).

  To assess the effect of 300 mg caffeine (CAFF) vs placebo (PLAC) vs no-pill (NoPill) on Muscle Lab force-velocity linear encoder morning rate of development of velocity (RDV), for bench press and back squat at 40, 60 and 80% 1RM (maximum repetition). The individual's own body mass was factored into the back squat exercise, as this is a whole-body movement, but not into the bench press. The MuscleLab force-velocity linear encoder (Muscle Lab, Ergotest version 4010, Norway) was attached to an Eleiko Olympic bar (20 kg) which was set upon rests on a standard squat rack, safety arms were set so that the participant achieved ≤90° knee flexion position (settings measured and recorded during the familiarization process). From this position, the participant was instructed to drive the bar upwards as forcefully as possible; the value recorded during the test was for the concentric phase of the action only.

  From familiarisation to the final experimental session (~4 weeks)

• Morning displacement (D, cm), for bench press and back squat at 40, 60 and 80% 1RM (maximum repetition).

  To assess the effect of 300 mg caffeine (CAFF) vs placebo (PLAC) vs no-pill (NoPill) on Muscle Lab force-velocity linear encoder morning displacement (D, cm), for bench press and back squat at 40, 60 and 80% 1RM (maximum repetition). The individual's own body mass was factored into the back squat exercise, as this is a whole-body movement, but not into the bench press. The MuscleLab force-velocity linear encoder (Muscle Lab, Ergotest version 4010, Norway) was attached to an Eleiko Olympic bar (20 kg) which was set upon rests on a standard squat rack, safety arms were set so that the participant achieved ≤90° knee flexion position (settings measured and recorded during the familiarization process). From this position, the participant was instructed to drive the bar upwards as forcefully as possible; the value recorded during the test was for the concentric phase of the action only.

  From familiarisation to the final experimental session (~4 weeks)

• Morning time-to-peak velocity (tPV, m/s/s), for bench press and back squat at 40, 60 and 80% 1RM (maximum repetition).

  To assess the effect of 300 mg caffeine (CAFF) vs placebo (PLAC) vs no-pill (NoPill) on Muscle Lab force-velocity linear encoder morning time-to-peak velocity (tPV, m/s/s), for bench press and back squat at 40, 60 and 80% 1RM (maximum repetition). The individual's own body mass was factored into the back squat exercise, as this is a whole-body movement, but not into the bench press. The MuscleLab force-velocity linear encoder (Muscle Lab, Ergotest version 4010, Norway) was attached to an Eleiko Olympic bar (20 kg) which was set upon rests on a standard squat rack, safety arms were set so that the participant achieved ≤90° knee flexion position (settings measured and recorded during the familiarization process). From this position, the participant was instructed to drive the bar upwards as forcefully as possible; the value recorded during the test was for the concentric phase of the action only.

  From familiarisation to the final experimental session (~4 weeks)

Secondary Outcomes (3)

• Morning Trail Making Test time to completion in seconds (TMT; parts A and B)

  From enrolment to last experimental session (4 weeks)

• Morning Rey Auditory Verbal Learning Test

  From familiarisation to the final experimental session (~4 weeks)

• Morning Stroop word-color interference test

  From familiarisation to the final experimental session (~4 weeks)

Other Outcomes (14)

• Rectal temperature

  From familiarisation to the final experimental session (~4 weeks)

• Skin temperature (Tsk)

  From familiarisation to the final experimental session (~4 weeks)

• The mean body temperature (Tmb)

  From familiarisation to the final experimental session (~4 weeks).

Study Arms (3)

Group 1

EXPERIMENTAL

1\) NoPill, 2) PLAC, 3) Caffeine (300 mg)

Drug: 300mg of of caffeine anhydrous in 3 capsules similar to PLACEBO in size and weight; Other: Placebo; Dietary Supplement: No Pill

Group 2

EXPERIMENTAL

1\) PLAC, 2) Caffeine (300 mg), 3) NoPill

Drug: 300mg of of caffeine anhydrous in 3 capsules similar to PLACEBO in size and weight; Other: Placebo; Dietary Supplement: No Pill

Group 3

EXPERIMENTAL

1\) Caffeine (300 mg), 2) NoPill, 3) PLAC

Drug: 300mg of of caffeine anhydrous in 3 capsules similar to PLACEBO in size and weight; Other: Placebo; Dietary Supplement: No Pill

Interventions

300mg of of caffeine anhydrous in 3 capsules similar to PLACEBO in size and weight DRUG

300mg of of caffeine anhydrous in 3 capsules similar to PLACEBO in size and weight

Group 1; Group 2; Group 3

Placebo OTHER

Description: 3 capsules of PLACEBO similar to caffeine condition in size and weight

Group 1; Group 2; Group 3

No Pill DIETARY_SUPPLEMENT

No capsules were given.

Group 1; Group 2; Group 3

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Healthy adults
• 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

You may not qualify if:

• Depressed mood (from the Beck depression inventory)
• Poor sleep quality (a Pittsburgh sleep quality index global score \>5
• Recent shiftwork or travel across multiple time-zones
• 'Extreme' chronotype (assessed via the Composite Morningness Questionnaire
• Risk factors and/or symptoms of cardiovascular disease.
• Minimal knowledge of the effects of time-of-day or time-since-sleep on human performance

Sponsors & Collaborators

• Liverpool John Moores University: lead

Study Sites (1)

Tom Reilly Building (LJMU)

Liverpool, Merseyside, L3 3AF, United Kingdom

Location

Related Publications (6)

• 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.

  PMID: 1365645 BACKGROUND

• Martins GL, Guilherme JPLF, Ferreira LHB, de Souza-Junior TP, Lancha AH Jr. Caffeine and Exercise Performance: Possible Directions for Definitive Findings. Front Sports Act Living. 2020 Dec 11;2:574854. doi: 10.3389/fspor.2020.574854. eCollection 2020.

  PMID: 33345139 BACKGROUND

• 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.

  PMID: 37589927 BACKGROUND

• Robertson CM, Pullinger SA, Robinson WR, Smith ME, Burniston JG, Edwards BJ. Circadian variation in muscle force output in males using isokinetic, isometric dynamometry: can we observe this in multi-joint movements using the muscleLab force-velocity encoder and are they similar in peak and magnitude? Chronobiol Int. 2024 May;41(5):709-724. doi: 10.1080/07420528.2024.2348011. Epub 2024 May 9.

  PMID: 38722075 BACKGROUND

• 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.

  PMID: 15865319 BACKGROUND

• 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.

  PMID: 33144349 BACKGROUND

MeSH Terms

Interventions

Weights and Measures

Intervention Hierarchy (Ancestors)

Investigative Techniques

Study Officials

• Ben J Edwards, PHD

  Liverpool John Moores University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Masking Details: Both researcher and participants did not know what of the two pill options were caffeine
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Reader Chronobiology and Environmental Physiology

Model Details: Double blinded counterbalanced design with three conditions

Study Record Dates

• First Submitted: February 25, 2026
• First Posted: March 12, 2026
• Study Start: November 15, 2024
• Primary Completion: July 25, 2025
• Study Completion: July 25, 2025
• Last Updated: March 13, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

GB (1)