Athletic PerformanceNCT07170228
Casein Supplementation: Pre-Sleep vs. Post-Exercise
A study testing Micellar Casein in people with Athletic Performance, run by Serdar Bayrakdaroğlu at 1 site in Turkey (Türkiye).
Trial summary
This randomized controlled trial aimed to investigate the effects of casein supplementation timing on post-exercise recovery and exercise performance in trained football players. Participants were allocated into three groups: pre-sleep casein ingestion, post-exercise casein ingestion, and control. Read more about this study
- Who is it for?
- Ages 18 to 25 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Athletic Performance
- What is being tested?
- Micellar Casein
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 24 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 10 Mar 2025to 14 Mar 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 25 years
- Men only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Male football players aged 18 to 25 years.
- At least three years of competitive soccer experience.
- Engaged in structured soccer training at least three times per week during the previous six months.
- Clearance to participate based on the Physical Activity Readiness Questionnaire (PAR-Q) (Thomas et al., 1992; Bredin et al., 2013).
- Provided written informed consent prior to participation.
Who cannot join
- Any musculoskeletal injury or surgery within the past six months.
- Reported milk or casein intolerance or allergy.
- Regular use of ergogenic supplements such as protein or creatine during the previous four weeks
- Medical conditions or limitations that could interfere with maximal exercise performance.
- Non-compliance with study procedures or training/testing protocols.
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Gumushane University, Faculty of Sport Sciences
Gümüşhane, Gümüşhane Province, 29100
About this study
Official title: The Effects of Casein Supplementation Timing on Exercise Performance: A Comparison Between Pre-Sleep and Post-Exercise Intake
This randomized controlled trial aimed to investigate the effects of casein supplementation timing on post-exercise recovery and exercise performance in trained football players. Participants were allocated into three groups: pre-sleep casein ingestion, post-exercise casein ingestion, and control. The study compared the effects of pre-sleep and post-exercise casein intake on anaerobic performance, agility, and recovery markers following a standardized high-intensity resistance training session.
Read the detailed description
Casein is a slow-digesting protein commonly used as a dietary supplement to promote muscle recovery and adaptation. Although casein is traditionally consumed before sleep to maximize overnight muscle protein synthesis, limited evidence exists regarding the optimal timing of casein ingestion relative to exercise.
This study employed a randomized controlled experimental design to compare the effects of pre-sleep versus post-exercise casein supplementation on recovery and performance outcomes in trained football players. Twenty-four male participants were stratified by playing position (defender, midfielder, forward) and randomized into three groups: pre-sleep casein ingestion group (PSCIG), post-exercise casein ingestion group (PECIG), and control group (CG). All participants first completed a familiarization session and pre-test assessments, including the countermovement jump (CMJ), Illinois Agility Test, and Running-based Anaerobic Sprint Test (RAST).
After the pre-tests, all players performed a standardized high-intensity resistance training protocol designed to induce muscle fatigue. Participants in the PECIG consumed 30 g of micellar casein dissolved in 300 mL of water within 10-15 minutes post-exercise, while participants in the PSCIG consumed the same supplement 30-60 minutes before sleep. The control group did not receive any supplementation. Twenty-four ± 1 hours after the resistance training, post-tests were conducted using the same protocols as the pre-tests.
The primary aim of this study was to determine whether casein supplementation timing (pre-sleep vs. post-exercise) differentially influences recovery and subsequent anaerobic performance. Outcomes from this trial may provide practical recommendations for athletes and coaches regarding optimal protein supplementation strategies to enhance recovery and performance.
- Conditions
- Athletic Performance
- Being tested
- Micellar Casein
- Keywords
- Casein Supplementation; Pre-Sleep Protein Intake; Post-Exercise Protein Intake; Muscle Recovery; Anaerobic Performance
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Micellar CaseinDietary supplement
Participants consumed 30 g of micellar casein powder dissolved in 300 mL of water.
Supplement timing varied by group:
Post-Exercise Casein Ingestion Group (PECIG): Taken 10-15 minutes after completing the standardized high-intensity resistance training session.
Pre-Sleep Casein Ingestion Group (PSCIG): Taken 30-60 minutes before bedtime on the same day as the training session.
The control group received no supplementation. All supplements were prepared and monitored by the research team to ensure dosage accuracy and participant compliance.
| Study group | Role | What they receive |
|---|---|---|
| Pre-Sleep Casein Ingestion Group | Experimental | Participants consumed 30 g of micellar casein dissolved in 300 mL of water 30-60 minutes before sleep following the standardized high-intensity resistance training session. Supplement intake was directly monitored by the research team to ensure compliance. Receives: Dietary Supplement: Micellar Casein |
| Post-Exercise Casein Ingestion Group | Experimental | Participants consumed 30 g of micellar casein dissolved in 300 mL of water 10-15 minutes after completing the standardized high-intensity resistance training session. Supplement preparation and intake were supervised by the research team. Receives: Dietary Supplement: Micellar Casein |
| Control Group | No intervention | Participants completed the standardized high-intensity resistance training protocol but did not receive any supplementation. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Peak Power (RAST Test)
Peak power will be calculated using body mass and sprint times obtained during the RAST test to assess maximal anaerobic performance. Measurements will be taken at baseline and 24 hours post-training.
Measured: Change from baseline (pre-test) to 24 hours post-training (post-test)
Secondary outcomes (4)
Mean Power (RAST Test)
Mean power will be calculated from total sprint time and body mass during the Running-based Anaerobic Sprint Test (RAST) to evaluate anaerobic endurance performance. Measurements will be collected pre- and 24 hours post-training.
Measured: Change from baseline (pre-test) to 24 hours post-training (post-test)
Fatigue Index (RAST Test)
Fatigue index will be calculated using the difference between the highest and lowest sprint times divided by the total sprint time during the RAST test. It reflects fatigue and recovery capacity. Measurements will be collected pre- and 24 hours post-training.
Measured: Change from baseline (pre-test) to 24 hours post-training (post-test)
Countermovement Jump (CMJ) Height
CMJ height will be measured using a validated jump mat system to assess lower-limb explosive power. Measurements will be collected pre- and 24 hours post-training under standardized conditions.
Measured: Change from baseline (pre-test) to 24 hours post-training (post-test)
Illinois Agility Test Time
Agility performance will be assessed using the Illinois Agility Test to evaluate change of direction speed and overall agility. Measurements will be collected pre- and 24 hours post-training under standardized environmental conditions.
Measured: Change from baseline (pre-test) to 24 hours post-training (post-test)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Sep 2025
- Study start10 Mar 2025
- Primary completion14 Mar 2025
- Study completion14 Mar 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Athletic PerformanceStudies 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
- Participants were randomized into three parallel groups: pre-sleep casein ingestion, post-exercise casein ingestion, or control, using stratified block randomization.
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 24 participants (actual)
Sponsor and investigators
- Lead sponsor
- Serdar Bayrakdaroğlu
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Serdar Bayrakdaroğlu, Gümüşhane Universıty
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07170228
- Sponsor's protocol ID
- GTU-2025-CASEIN01
- Other IDs
- Ethics Committee -GTU-EC-2024
- Status last verified
- Sep 2025
- First submitted
- 5 Sep 2025
- Last updated
- 12 Sep 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be shared because of privacy concerns and restrictions imposed by the ethics committee approval.
Study at a glance
From the registry record, last updated by the sponsor on 12 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effects of Casein Supplementation Timing on Exercise Performance: A Comparison Between Pre-Sleep and Post-Exercise Intake
- ClinicalTrials.gov ID
- NCT07170228
- Acronym / sponsor ID
- GTU-2025-CASEIN01
- Conditions
- Athletic Performance
- Keywords
- Casein Supplementation; Pre-Sleep Protein Intake; Post-Exercise Protein Intake; Muscle Recovery; Anaerobic Performance
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 24 participants (actual)
- Lead sponsor
- Serdar BayrakdaroğluUniversity, hospital or other
- Study start
- 10 Mar 2025 (actual)
- Primary completion
- 14 Mar 2025 (actual)
- Study completion
- 14 Mar 2025 (actual)
- First posted
- 12 Sep 2025 (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 randomized controlled trial aimed to investigate the effects of casein supplementation timing on post-exercise recovery and exercise performance in trained football players. Participants were allocated into three groups: pre-sleep casein ingestion, post-exercise casein ingestion, and control. The study compared the effects of pre-sleep and post-exercise casein intake on anaerobic performance, agility, and recovery markers following a standardized high-intensity resistance training session.
Detailed description
Casein is a slow-digesting protein commonly used as a dietary supplement to promote muscle recovery and adaptation. Although casein is traditionally consumed before sleep to maximize overnight muscle protein synthesis, limited evidence exists regarding the optimal timing of casein ingestion relative to exercise.
This study employed a randomized controlled experimental design to compare the effects of pre-sleep versus post-exercise casein supplementation on recovery and performance outcomes in trained football players. Twenty-four male participants were stratified by playing position (defender, midfielder, forward) and randomized into three groups: pre-sleep casein ingestion group (PSCIG), post-exercise casein ingestion group (PECIG), and control group (CG). All participants first completed a familiarization session and pre-test assessments, including the countermovement jump (CMJ), Illinois Agility Test, and Running-based Anaerobic Sprint Test (RAST).
After the pre-tests, all players performed a standardized high-intensity resistance training protocol designed to induce muscle fatigue. Participants in the PECIG consumed 30 g of micellar casein dissolved in 300 mL of water within 10-15 minutes post-exercise, while participants in the PSCIG consumed the same supplement 30-60 minutes before sleep. The control group did not receive any supplementation. Twenty-four ± 1 hours after the resistance training, post-tests were conducted using the same protocols as the pre-tests.
The primary aim of this study was to determine whether casein supplementation timing (pre-sleep vs. post-exercise) differentially influences recovery and subsequent anaerobic performance. Outcomes from this trial may provide practical recommendations for athletes and coaches regarding optimal protein supplementation strategies to enhance recovery and performance.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 3
- Model description
- Participants were randomized into three parallel groups: pre-sleep casein ingestion, post-exercise casein ingestion, or control, using stratified block randomization.
| Arm | Type | Receives |
|---|---|---|
| Pre-Sleep Casein Ingestion Group | Experimental | Dietary Supplement: Micellar CaseinParticipants consumed 30 g of micellar casein dissolved in 300 mL of water 30-60 minutes before sleep following the standardized high-intensity resistance training session. Supplement intake was directly monitored by the research team to ensure compliance. |
| Post-Exercise Casein Ingestion Group | Experimental | Dietary Supplement: Micellar CaseinParticipants consumed 30 g of micellar casein dissolved in 300 mL of water 10-15 minutes after completing the standardized high-intensity resistance training session. Supplement preparation and intake were supervised by the research team. |
| Control Group | No intervention | –Participants completed the standardized high-intensity resistance training protocol but did not receive any supplementation. |
Who may qualify
- Ages
- 18 to 25 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Male football players aged 18 to 25 years.
- At least three years of competitive soccer experience.
- Engaged in structured soccer training at least three times per week during the previous six months.
- Clearance to participate based on the Physical Activity Readiness Questionnaire (PAR-Q) (Thomas et al., 1992; Bredin et al., 2013).
- Provided written informed consent prior to participation.
Key exclusion criteria (5 listed)
- Any musculoskeletal injury or surgery within the past six months.
- Reported milk or casein intolerance or allergy.
- Regular use of ergogenic supplements such as protein or creatine during the previous four weeks
- Medical conditions or limitations that could interfere with maximal exercise performance.
- Non-compliance with study procedures or training/testing protocols.
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 |
|---|---|---|
| Micellar CaseinParticipants consumed 30 g of micellar casein powder dissolved in 300 mL of water. Supplement timing varied by group: Post-Exercise Casein Ingestion Group (PECIG): Taken 10-15 minutes after completing the standardized high-intensity resistance training session. Pre-Sleep Casein Ingestion Group (PSCIG): Taken 30-60 minutes before bedtime on the same day as the training session. The control group received no supplementation. All supplements were prepared and monitored by the research team to ensure dosage accuracy and participant compliance. | Dietary supplement | Post-Exercise Casein Ingestion Group, Pre-Sleep Casein Ingestion Group |
Primary outcome
Peak Power (RAST Test)
Time frame: Change from baseline (pre-test) to 24 hours post-training (post-test)
Peak power will be calculated using body mass and sprint times obtained during the RAST test to assess maximal anaerobic performance. Measurements will be taken at baseline and 24 hours post-training.
4 secondary outcomes
Mean Power (RAST Test)
Time frame: Change from baseline (pre-test) to 24 hours post-training (post-test)
Fatigue Index (RAST Test)
Time frame: Change from baseline (pre-test) to 24 hours post-training (post-test)
Countermovement Jump (CMJ) Height
Time frame: Change from baseline (pre-test) to 24 hours post-training (post-test)
Illinois Agility Test Time
Time frame: Change from baseline (pre-test) to 24 hours post-training (post-test)
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 12 Sep 2025.
- Individual participant dataSharing planned: No. Individual participant data will not be shared because of privacy concerns and restrictions imposed by the ethics committee approval.
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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.
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 Micellar Casein in people with Athletic Performance, run by Serdar Bayrakdaroğlu 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 5 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: finished, as of the sponsor's last update on 12 Sep 2025. 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. 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?
Peak Power (RAST Test) (time frame: Change from baseline (pre-test) to 24 hours post-training (post-test)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 Sep 2025.