Muscle HypotrophyNCT07410195
Resistance Training Adaptations and Caffeine Intake
A study testing Caffeine (Constant Daily Dose), Caffeine (Escalating Dose) and Caffeine (Training Days Only) in people with Muscle Hypotrophy and Exercise Performance, run by Istanbul University - Cerrahpasa at 1 site in Turkey (Türkiye).
Trial summary
This parallel-group, randomized, double-blind, placebo-controlled trial investigates the effects of three different caffeine supplementation strategies on resistance training-induced adaptations in 120 caffeine-naive, inactive young adult males. Read more about this study
- Who is it for?
- Ages 18 to 30 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Muscle Hypotrophy, Exercise Performance, Muscle Strength
- What is being tested?
- Caffeine (Constant Daily Dose), Caffeine (Escalating Dose) and Caffeine (Training Days Only)
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 120 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 20 Feb 2026to 7 Jun 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 30 years
- Men only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Male sex and age between 18 and 30 years
- Daily caffeine intake <100 mg/day
- resistance-training experience ≥1 year and <3 years
- Body mass index (BMI) between 18.5-25 kg/m2
- Willingness to attend all training and testing sessions regularly
- Provision of written informed consent after being fully informed about the study
Who cannot join
- Presence of cardiovascular, metabolic, renal, hepatic, or other serious chronic diseases
- Diagnosed psychiatric disorders or severe caffeine intolerance/allergy
- Use of medications affecting caffeine metabolism or muscle anabolism (e.g., beta-blockers, antidepressants, anabolic steroids)
- Musculoskeletal injuries that prevent safe resistance training
- Smoking or alcohol consumption at levels that could affect study outcomes
- Concurrent participation in another exercise intervention study
- Inability to tolerate DXA scanning or blood sampling
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Istanbul University-Cerrahpasa, Faculty of Sport Sciences Performance Laboratory
Istanbul, Avcilar, 34010
About this study
Official title: Study of Different Caffeine Supplementation Strategies on Resistance Training-Induced Adaptations
This parallel-group, randomized, double-blind, placebo-controlled trial investigates the effects of three different caffeine supplementation strategies on resistance training-induced adaptations in 120 caffeine-naive, inactive young adult males. Participants will undergo a 10-week supervised resistance training program. The four supplementation strategies are: (1) constant daily low-moderate dosing (4 mg/kg/day), (2) gradually escalating dose (2 to 6 mg/kg across weeks), (3) training-day-only caffeine (4 mg/kg/day), and (4) placebo. Primary outcomes include maximal strength, body composition (lean body mass and fat mass), skeletal muscle thickness, and training volume progression. Secondary outcomes include muscular endurance, jump height, flight-time-to-contraction-time (FT:CT) ratio, mechanistic/biological variables (epinephrine, norepinephrine, cortisol, testosterone, creatine kinase, IGF-1), rate of perceived exertion, sleep/recovery parameters, and adverse effects.
Read the detailed description
BACKGROUND: Caffeine is a well-established acute ergogenic aid that reliably improves endurance, power, and resistance-exercise performance when consumed at typical ergogenic doses (approximately 2-6 mg/kg about 60 minutes pre-exercise). However, whether caffeine exerts direct biological effects on muscle protein balance and hypertrophy remains unclear. Regular caffeine ingestion produces partial physiological tolerance, creating the possibility that chronic supplementation elicits different outcomes than acute dosing. OBJECTIVES: This study addresses three translational questions: (1) Does constant daily low-moderate dosing potentiate training adaptations? (2) Does a gradually escalating dose strategy produce greater effects by overcoming tolerance? (3) Does training-day-only caffeine preserve acute ergogenic effects while limiting tolerance and sleep disturbance? METHODS: 120 caffeine-naive, physically inactive young adult males aged 18-30 years will be randomly assigned to one of the following groups (n=30 per group): (1) constant daily low-moderate dosing (CON, 4 mg/kg/day), (2) gradually escalating dose (ESC, 2 to 6 mg/kg across weeks), (3) training-day-only caffeine (TDO, 4 mg/kg/day), and (4) placebo (PLA). All participants will undergo supervised resistance training 3 times per week. OUTCOMES: Primary endpoints include maximal strength, body composition (lean body mass and fat mass), skeletal muscle thickness, and training volume metrics. Secondary outcomes include muscular endurance, jump height, flight-time-to-contraction-time (FT:CT) ratio, mechanistic/biological variables (epinephrine, norepinephrine, cortisol, testosterone, creatine kinase, IGF-1), rate of perceived exertion, sleep/recovery parameters, and adverse effects. STATISTICAL ANALYSIS: Linear Mixed Models will be used to analyze the data.
- Conditions
- Muscle Hypotrophy, Exercise Performance, Muscle Strength, Adaptation
- Being tested
- Caffeine (Constant Daily Dose), Caffeine (Escalating Dose), Caffeine (Training Days Only), placebo capsule
- Keywords
- Caffeine, Resistance Training, Muscle Adaptation, Supplementation, Strength Training, Hypertrophy
- Medical subject headings
- Muscular Atrophy, Hypertrophy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Caffeine (Constant Daily Dose)Dietary supplement
Oral caffeine capsule at 4 mg/kg body weight, consumed daily approximately 60 minutes before training sessions (on training days) or at the same time of day (on rest days).
Caffeine (Escalating Dose)Dietary supplement
- Oral caffeine starting at 2 mg/kg/day and increasing incrementally to reach 6 mg/kg/day by week 10.
Caffeine (Training Days Only)Dietary supplement
Oral caffeine capsule at 4 mg/kg body weight, consumed only on training days approximately 60 minutes before exercise.
placebo capsuleDietary supplement
Oral placebo capsule (250 mg cellulose), consumed daily approximately 60 minutes before training sessions (on training days) or at the same time of day (on rest days).
| Study group | Role | What they receive |
|---|---|---|
| Strategy 1: Constant Daily Dose | Experimental | Participants receive caffeine at a constant daily dose of 4 mg/kg/day for 10 weeks. Supervised resistance training is performed 3 times per week for 10 weeks. Receives: Dietary Supplement: Caffeine (Constant Daily Dose) |
| Strategy 2: Escalating Dose | Experimental | Participants receive caffeine at a gradually escalating dose, starting at 2 mg/kg/day in week 1 and increasing to 6 mg/kg/day by week 10 (1 mg/kg every 2 weeks). Supervised resistance training is performed 3 times per week for 10 weeks. Receives: Dietary Supplement: Caffeine (Escalating Dose) |
| Strategy 3: Training Days Only | Experimental | Participants receive caffeine at 4 mg/kg only on training days (3 times per week) for 10 weeks. Supervised resistance training is performed 3 times per week for 10 weeks. Receives: Dietary Supplement: Caffeine (Training Days Only) |
| Placebo | Placebo comparator | Participants receive 250 mg/day cellulose for 10 weeks. Supervised resistance training is performed 3 times per week for 10 weeks. Receives: Dietary Supplement: placebo capsule |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Lean Body Mass Measured by DXA
Change in total lean body mass measured using dual-energy X-ray absorptiometry (DXA), reported in kilograms.
Measured: Baseline and post-test (after completing 10 weeks of interventions)
Change in Fat Mass Measured by DXA
Change in fat mass measured using DXA.
Measured: Baseline and post-test (after completing 10 weeks of interventions)
Maximal Strength
Measure by one-repetition maximum (1-RM) on a lower body (Smith machine Back Squat) and two upper body (Bench Press machine and Lat Pulldown machine) exercises.
Measured: Baseline, and post-test (after completing 10 weeks of interventions)
Total Training Volume Load
Total training volume load calculated as the sum of lifted load using the formula (kilograms × repetitions × sets) accumulated during each intervention period.
Measured: During the intervention period (all training sessions).
Change in Skeletal Muscle Thickness
Change in skeletal muscle thickness measured using B-mode ultrasound, reported in mm.
Measured: Baseline and post-test (after completing 10 weeks of interventions)
Secondary outcomes (13)
Muscular endurance
It will be measured by a repetitions-to-failure test on the Smith machine back squat using a load corresponding to 60% of the current 1RM.
Measured: Baseline, and post-test (after completing 10 weeks of interventions)
Neuromuscular function
It will be measured by the countermovement jump (CMJ) test on a force platform.
Measured: Baseline and post-test (after completing 10 weeks of interventions)
Resting concentrations of testosterone
They will be measured using standard biochemical analyses.
Measured: Baseline, and post-test (after completing 10 weeks of interventions)
Plasma epinephrine responses to exercise
They will be measured using standard biochemical analyses.
Measured: During the first training session of Week 1 and the final training session of Week 10, at three time points: (1) pre-supplementation, (2) immediately before exercise and (3) immediately after exercise.
Recovery
It will be assessed using the validated 0-10 Perceived Recovery Status Scale (0 to 2: very poorly recovered, 3 to 4: poorly recovered, 5 to 6: adequately recovered, 7 to 8: well recovered, and 9 to 10: fully recovered).
Measured: Before each of the 30 training sessions during the study.
Adverse Events
Adverse events will be assessed using a standardized questionnaire administered throughout the study.
Measured: From initiation of the 4-week caffeine abstinence period through completion of the post-intervention assessments, monitored throughout the study (approximately 16 weeks).
Sleep quality
It will be assessed by the Pittsburgh Sleep Quality Index (PSQI).
Measured: Baseline and post-test (after completing 10 weeks of interventions).
Rate of perceived exertion
Assessed using the Borg Category-Ratio (CR10) Scale, ranging from 0 ("nothing at all") to 10 ("maximal"). Participants will report their perceived exertion after each supervised training session.
Measured: After each supervised training session, participants were assessed throughout the 10-week intervention period (30 training sessions).
Resting concentrations of insulin-like growth factor-1 (IGF-1)
They will be measured using standard biochemical analyses.
Measured: Baseline, and post-test (after completing 10 weeks of interventions)
Resting concentrations of cortisol
They will be measured using standard biochemical analyses.
Measured: Baseline, and post-test (after completing 10 weeks of interventions)
Resting concentrations of creatine kinase
They will be measured using standard biochemical analyses.
Measured: Baseline, and post-test (after completing 10 weeks of interventions)
Serum cortisol responses to exercise
They will be measured using standard biochemical analyses.
Measured: During the first training session of Week 1 and the final training session of Week 10, at three time points: (1) pre-supplementation, (2) immediately before exercise and (3) immediately after exercise.
Plasma norepinephrine responses to exercise
They will be measured using standard biochemical analyses.
Measured: During the first training session of Week 1 and the final training session of Week 10, at three time points: (1) pre-supplementation, (2) immediately before exercise and (3) immediately after exercise.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Feb 2026
- Study start20 Feb 2026
- Primary completion30 May 2026
- Study completion7 Jun 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (7)Papers the sponsor has linked to this study.
- Other trials for Muscle HypotrophyStudies 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
- Parallel groups
- Model description
- This is a parallel-group, randomized, double-blind, placebo-controlled trial with four parallel supplementation strategies: (1) constant daily low-moderate dosing (4 mg/kg/day), (2) gradually escalating dose (2 to 6 mg/kg across weeks), (3) training-day-only caffeine (4 mg/kg/day), and (4) placebo. All participants undergo supervised resistance training three times per week.
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 120 participants (actual)
Sponsor and investigators
- Lead sponsor
- Istanbul University - Cerrahpasa
- Sponsor type
- University, hospital or other
- Collaborators
- İstanbul Yeni Yüzyıl Üniversitesi
- Responsible party
- Principal investigator, Abdullah Demirli, Istanbul University - Cerrahpasa
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07410195
- Sponsor's protocol ID
- 2026/01-1792
- Status last verified
- Jul 2026
- First submitted
- 30 Jan 2026
- Last updated
- 14 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: All extracted personal data (IPD) from this information will be shared along with supporting data for the publication results. Data dictionaries relating to data settings are also stored.
Publications
Lovallo WR, Whitsett TL, al'Absi M, Sung BH, Vincent AS, Wilson MF. Caffeine stimulation of cortisol secretion across the waking hours in relation to caffeine intake levels. Psychosom Med. 2005 Sep-Oct;67(5):734-9. doi: 10.1097/01.psy.0000181270.20036.06.
PubMed 16204431Matsumura T, Takamura Y, Fukuzawa K, Nakagawa K, Nonoyama S, Tomoo K, Tsukamoto H, Shinohara Y, Iemitsu M, Nagano A, Isaka T, Hashimoto T. Ergogenic Effects of Very Low to Moderate Doses of Caffeine on Vertical Jump Performance. Int J Sport Nutr Exerc Metab. 2023 Jul 26;33(5):275-281. doi: 10.1123/ijsnem.2023-0061. Print 2023 Sep 1.
PubMed 37414404Brook MS, Wilkinson DJ, Mitchell WK, Lund JN, Szewczyk NJ, Greenhaff PL, Smith K, Atherton PJ. Skeletal muscle hypertrophy adaptations predominate in the early stages of resistance exercise training, matching deuterium oxide-derived measures of muscle protein synthesis and mechanistic target of rapamycin complex 1 signaling. FASEB J. 2015 Nov;29(11):4485-96. doi: 10.1096/fj.15-273755. Epub 2015 Jul 13.
PubMed 26169934Pickering C, Kiely J. Are low doses of caffeine as ergogenic as higher doses? A critical review highlighting the need for comparison with current best practice in caffeine research. Nutrition. 2019 Nov-Dec;67-68:110535. doi: 10.1016/j.nut.2019.06.016. Epub 2019 Jun 26.
PubMed 31400738Grgic J, Trexler ET, Lazinica B, Pedisic Z. Effects of caffeine intake on muscle strength and power: a systematic review and meta-analysis. J Int Soc Sports Nutr. 2018 Mar 5;15:11. doi: 10.1186/s12970-018-0216-0. eCollection 2018.
PubMed 29527137Guest NS, VanDusseldorp TA, Nelson MT, Grgic J, Schoenfeld BJ, Jenkins NDM, Arent SM, Antonio J, Stout JR, Trexler ET, Smith-Ryan AE, Goldstein ER, Kalman DS, Campbell BI. International society of sports nutrition position stand: caffeine and exercise performance. J Int Soc Sports Nutr. 2021 Jan 2;18(1):1. doi: 10.1186/s12970-020-00383-4.
PubMed 33388079Grgic J, Grgic I, Pickering C, Schoenfeld BJ, Bishop DJ, Pedisic Z. Wake up and smell the coffee: caffeine supplementation and exercise performance-an umbrella review of 21 published meta-analyses. Br J Sports Med. 2020 Jun;54(11):681-688. doi: 10.1136/bjsports-2018-100278. Epub 2019 Mar 29.
PubMed 30926628
Study at a glance
From the registry record, last updated by the sponsor on 14 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Study of Different Caffeine Supplementation Strategies on Resistance Training-Induced Adaptations
- ClinicalTrials.gov ID
- NCT07410195
- Acronym / sponsor ID
- 2026/01-1792
- Conditions
- Muscle Hypotrophy, Exercise Performance, Muscle Strength, Adaptation
- Keywords
- Caffeine, Resistance Training, Muscle Adaptation, Supplementation, Strength Training, Hypertrophy
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 120 participants (actual)
- Lead sponsor
- Istanbul University - CerrahpasaUniversity, hospital or other
- Collaborators
- İstanbul Yeni Yüzyıl Üniversitesi
- Study start
- 20 Feb 2026 (actual)
- Primary completion
- 30 May 2026 (actual)
- Study completion
- 7 Jun 2026 (actual)
- First posted
- 13 Feb 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.
This parallel-group, randomized, double-blind, placebo-controlled trial investigates the effects of three different caffeine supplementation strategies on resistance training-induced adaptations in 120 caffeine-naive, inactive young adult males. Participants will undergo a 10-week supervised resistance training program. The four supplementation strategies are: (1) constant daily low-moderate dosing (4 mg/kg/day), (2) gradually escalating dose (2 to 6 mg/kg across weeks), (3) training-day-only caffeine (4 mg/kg/day), and (4) placebo. Primary outcomes include maximal strength, body composition (lean body mass and fat mass), skeletal muscle thickness, and training volume progression. Secondary outcomes include muscular endurance, jump height, flight-time-to-contraction-time (FT:CT) ratio, mechanistic/biological variables (epinephrine, norepinephrine, cortisol, testosterone, creatine kinase, IGF-1), rate of perceived exertion, sleep/recovery parameters, and adverse effects.
Detailed description
BACKGROUND: Caffeine is a well-established acute ergogenic aid that reliably improves endurance, power, and resistance-exercise performance when consumed at typical ergogenic doses (approximately 2-6 mg/kg about 60 minutes pre-exercise). However, whether caffeine exerts direct biological effects on muscle protein balance and hypertrophy remains unclear. Regular caffeine ingestion produces partial physiological tolerance, creating the possibility that chronic supplementation elicits different outcomes than acute dosing. OBJECTIVES: This study addresses three translational questions: (1) Does constant daily low-moderate dosing potentiate training adaptations? (2) Does a gradually escalating dose strategy produce greater effects by overcoming tolerance? (3) Does training-day-only caffeine preserve acute ergogenic effects while limiting tolerance and sleep disturbance? METHODS: 120 caffeine-naive, physically inactive young adult males aged 18-30 years will be randomly assigned to one of the following groups (n=30 per group): (1) constant daily low-moderate dosing (CON, 4 mg/kg/day), (2) gradually escalating dose (ESC, 2 to 6 mg/kg across weeks), (3) training-day-only caffeine (TDO, 4 mg/kg/day), and (4) placebo (PLA). All participants will undergo supervised resistance training 3 times per week. OUTCOMES: Primary endpoints include maximal strength, body composition (lean body mass and fat mass), skeletal muscle thickness, and training volume metrics. Secondary outcomes include muscular endurance, jump height, flight-time-to-contraction-time (FT:CT) ratio, mechanistic/biological variables (epinephrine, norepinephrine, cortisol, testosterone, creatine kinase, IGF-1), rate of perceived exertion, sleep/recovery parameters, and adverse effects. STATISTICAL ANALYSIS: Linear Mixed Models will be used to analyze the data.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 4
- Model description
- This is a parallel-group, randomized, double-blind, placebo-controlled trial with four parallel supplementation strategies: (1) constant daily low-moderate dosing (4 mg/kg/day), (2) gradually escalating dose (2 to 6 mg/kg across weeks), (3) training-day-only caffeine (4 mg/kg/day), and (4) placebo. All participants undergo supervised resistance training three times per week.
| Arm | Type | Receives |
|---|---|---|
| Strategy 1: Constant Daily Dose | Experimental | Dietary Supplement: Caffeine (Constant Daily Dose)Participants receive caffeine at a constant daily dose of 4 mg/kg/day for 10 weeks. Supervised resistance training is performed 3 times per week for 10 weeks. |
| Strategy 2: Escalating Dose | Experimental | Dietary Supplement: Caffeine (Escalating Dose)Participants receive caffeine at a gradually escalating dose, starting at 2 mg/kg/day in week 1 and increasing to 6 mg/kg/day by week 10 (1 mg/kg every 2 weeks). Supervised resistance training is performed 3 times per week for 10 weeks. |
| Strategy 3: Training Days Only | Experimental | Dietary Supplement: Caffeine (Training Days Only)Participants receive caffeine at 4 mg/kg only on training days (3 times per week) for 10 weeks. Supervised resistance training is performed 3 times per week for 10 weeks. |
| Placebo | Placebo comparator | Dietary Supplement: placebo capsuleParticipants receive 250 mg/day cellulose for 10 weeks. Supervised resistance training is performed 3 times per week for 10 weeks. |
Who may qualify
- Ages
- 18 to 30 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (6 listed)
- Male sex and age between 18 and 30 years
- Daily caffeine intake <100 mg/day
- resistance-training experience ≥1 year and <3 years
- Body mass index (BMI) between 18.5-25 kg/m2
- Willingness to attend all training and testing sessions regularly
Key exclusion criteria (7 listed)
- Presence of cardiovascular, metabolic, renal, hepatic, or other serious chronic diseases
- Diagnosed psychiatric disorders or severe caffeine intolerance/allergy
- Use of medications affecting caffeine metabolism or muscle anabolism (e.g., beta-blockers, antidepressants, anabolic steroids)
- Musculoskeletal injuries that prevent safe resistance training
- Smoking or alcohol consumption at levels that could affect study outcomes
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 (Constant Daily Dose)Oral caffeine capsule at 4 mg/kg body weight, consumed daily approximately 60 minutes before training sessions (on training days) or at the same time of day (on rest days). | Dietary supplement | Strategy 1: Constant Daily Dose |
| Caffeine (Escalating Dose)• Oral caffeine starting at 2 mg/kg/day and increasing incrementally to reach 6 mg/kg/day by week 10. | Dietary supplement | Strategy 2: Escalating Dose |
| Caffeine (Training Days Only)Oral caffeine capsule at 4 mg/kg body weight, consumed only on training days approximately 60 minutes before exercise. | Dietary supplement | Strategy 3: Training Days Only |
| placebo capsuleOral placebo capsule (250 mg cellulose), consumed daily approximately 60 minutes before training sessions (on training days) or at the same time of day (on rest days). | Dietary supplement | Placebo |
Primary outcome
Change in Lean Body Mass Measured by DXA
Time frame: Baseline and post-test (after completing 10 weeks of interventions)
Change in total lean body mass measured using dual-energy X-ray absorptiometry (DXA), reported in kilograms.
Change in Fat Mass Measured by DXA
Time frame: Baseline and post-test (after completing 10 weeks of interventions)
Change in fat mass measured using DXA.
Maximal Strength
Time frame: Baseline, and post-test (after completing 10 weeks of interventions)
Measure by one-repetition maximum (1-RM) on a lower body (Smith machine Back Squat) and two upper body (Bench Press machine and Lat Pulldown machine) exercises.
Total Training Volume Load
Time frame: During the intervention period (all training sessions).
Total training volume load calculated as the sum of lifted load using the formula (kilograms × repetitions × sets) accumulated during each intervention period.
Change in Skeletal Muscle Thickness
Time frame: Baseline and post-test (after completing 10 weeks of interventions)
Change in skeletal muscle thickness measured using B-mode ultrasound, reported in mm.
13 secondary outcomes
Muscular endurance
Time frame: Baseline, and post-test (after completing 10 weeks of interventions)
Neuromuscular function
Time frame: Baseline and post-test (after completing 10 weeks of interventions)
Resting concentrations of testosterone
Time frame: Baseline, and post-test (after completing 10 weeks of interventions)
Plasma epinephrine responses to exercise
Time frame: During the first training session of Week 1 and the final training session of Week 10, at three time points: (1) pre-supplementation, (2) immediately before exercise and (3) immediately after exercise.
Recovery
Time frame: Before each of the 30 training sessions during the study.
Adverse Events
Time frame: From initiation of the 4-week caffeine abstinence period through completion of the post-intervention assessments, monitored throughout the study (approximately 16 weeks).
Sleep quality
Time frame: Baseline and post-test (after completing 10 weeks of interventions).
Rate of perceived exertion
Time frame: After each supervised training session, participants were assessed throughout the 10-week intervention period (30 training sessions).
Resting concentrations of insulin-like growth factor-1 (IGF-1)
Time frame: Baseline, and post-test (after completing 10 weeks of interventions)
Resting concentrations of cortisol
Time frame: Baseline, and post-test (after completing 10 weeks of interventions)
Resting concentrations of creatine kinase
Time frame: Baseline, and post-test (after completing 10 weeks of interventions)
Serum cortisol responses to exercise
Time frame: During the first training session of Week 1 and the final training session of Week 10, at three time points: (1) pre-supplementation, (2) immediately before exercise and (3) immediately after exercise.
Plasma norepinephrine responses to exercise
Time frame: During the first training session of Week 1 and the final training session of Week 10, at three time points: (1) pre-supplementation, (2) immediately before exercise and (3) immediately after exercise.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Jul 2026.
- Background: PubMed 16204431Lovallo WR, Whitsett TL, al'Absi M, Sung BH, Vincent AS, Wilson MF. Caffeine stimulation of cortisol secretion across the waking hours in relation to caffeine intake levels. Psychosom Med. 2005 Sep-Oct;67(5):734-9. doi: 10.1097/01.psy.0000181270.20036.06.
- Background: PubMed 37414404Matsumura T, Takamura Y, Fukuzawa K, Nakagawa K, Nonoyama S, Tomoo K, Tsukamoto H, Shinohara Y, Iemitsu M, Nagano A, Isaka T, Hashimoto T. Ergogenic Effects of Very Low to Moderate Doses of Caffeine on Vertical Jump Performance. Int J Sport Nutr Exerc Metab. 2023 Jul 26;33(5):275-281. doi: 10.1123/ijsnem.2023-0061. Print 2023 Sep 1.
- Background: PubMed 26169934Brook MS, Wilkinson DJ, Mitchell WK, Lund JN, Szewczyk NJ, Greenhaff PL, Smith K, Atherton PJ. Skeletal muscle hypertrophy adaptations predominate in the early stages of resistance exercise training, matching deuterium oxide-derived measures of muscle protein synthesis and mechanistic target of rapamycin complex 1 signaling. FASEB J. 2015 Nov;29(11):4485-96. doi: 10.1096/fj.15-273755. Epub 2015 Jul 13.
- Background: PubMed 31400738Pickering C, Kiely J. Are low doses of caffeine as ergogenic as higher doses? A critical review highlighting the need for comparison with current best practice in caffeine research. Nutrition. 2019 Nov-Dec;67-68:110535. doi: 10.1016/j.nut.2019.06.016. Epub 2019 Jun 26.
- Background: PubMed 29527137Grgic J, Trexler ET, Lazinica B, Pedisic Z. Effects of caffeine intake on muscle strength and power: a systematic review and meta-analysis. J Int Soc Sports Nutr. 2018 Mar 5;15:11. doi: 10.1186/s12970-018-0216-0. eCollection 2018.
- Background: PubMed 33388079Guest NS, VanDusseldorp TA, Nelson MT, Grgic J, Schoenfeld BJ, Jenkins NDM, Arent SM, Antonio J, Stout JR, Trexler ET, Smith-Ryan AE, Goldstein ER, Kalman DS, Campbell BI. International society of sports nutrition position stand: caffeine and exercise performance. J Int Soc Sports Nutr. 2021 Jan 2;18(1):1. doi: 10.1186/s12970-020-00383-4.
- Background: PubMed 30926628Grgic J, Grgic I, Pickering C, Schoenfeld BJ, Bishop DJ, Pedisic Z. Wake up and smell the coffee: caffeine supplementation and exercise performance-an umbrella review of 21 published meta-analyses. Br J Sports Med. 2020 Jun;54(11):681-688. doi: 10.1136/bjsports-2018-100278. Epub 2019 Mar 29.
- Individual participant dataSharing planned: Yes. All extracted personal data (IPD) from this information will be shared along with supporting data for the publication results. Data dictionaries relating to data settings are also stored.
Related trials for Muscle Hypotrophy
Active, not recruitingObservational study
A Study of the Safety of Nusinersen (Spinraza®) and Its Effects on Motor Function in Koreans Living With SMA Treated During Their Usual Medical Care
Muscular Atrophy, Spinal
Active, not recruitingObservational study
Possible Sarcopenia, Sarcopenia, and Functional Status in Patients With Primary Sjögren's Syndrome
Primary Sjögren Syndrome, Sarcopenia
Not yet recruiting
PROfiles of FGF-19 Post-prandial Secretion in Older Adults With Frailty and Without Frailty
Frailty, Sarcopenia
Recruiting
SMAdult - Monitoring of Movement on Spinal Muscular Atrophy
Spinal Amyotrophy
Recruiting
Characterization and Longitudinal Monitoring of Muscular Phenotype in Patients Admitted to Intensive Care for Sepsis
Sepsis, Myopathy Critical Illness
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Caffeine (Constant Daily Dose), Caffeine (Escalating Dose) and Caffeine (Training Days Only) in people with Muscle Hypotrophy and Exercise Performance, run by Istanbul University - Cerrahpasa at 1 site in Turkey (Türkiye).
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 6 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 14 Jul 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 Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Lean Body Mass Measured by DXA (time frame: Baseline and post-test (after completing 10 weeks of interventions)). The study lists 5 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 NCT07410195, which also lists 7 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 14 Jul 2026.