TCP-600 Supplementation and Performance Response in Professional Football Players (TCP600-RESP)

External Validation and Extension of Physical, Recovery, and Perceptual-Cognitive Responder Profiles After Phosphatidylserine-Containing Taurine-Caffeine Supplementation in Professional Football Players: A Randomized, Double-Blind, Placebo-Controlled Trial

This study will examine whether a 14-day supplementation protocol containing taurine, caffeine, and phosphatidylserine can help professional male football players maintain physical performance, cognitive function, recovery-related readiness, and selected football-specific perceptual-cognitive performance. Participants will be randomly assigned to receive either placebo or a phosphatidylserine-containing multi-ingredient supplement.

Before and after the supplementation period, players will complete non-invasive assessments such as sprint testing, reaction-time testing, heart rate variability monitoring, wellness/readiness questionnaires, mental-fatigue measures, and selected football-specific perceptual-cognitive tasks where available.

The study is designed as an external validation and extension of responder profiles derived from previous randomized controlled trials. Data from previous trials and this validation cohort will be used to examine whether baseline physical, cognitive, autonomic, fatigue-related, recovery-related, or perceptual-cognitive characteristics can predict which players are most likely to benefit from phosphatidylserine-containing multi-ingredient supplementation.

Study Overview

• Status: Not yet recruiting
• Conditions: Athletic Performance; Exercise Recovery; Cognitive Fatigue; Football-Specific Performance; Perceptual-cognitive Performance
• Intervention / Treatment: Other: Placebo; Dietary supplement: TCP-600 Supplementation; Dietary supplement: Taurine + Caffeine

Detailed Description

This is a randomized, double-blind, placebo-controlled validation study conducted in professional male football players. The study is designed to externally validate and extend individual responder profiles previously derived from randomized controlled trials investigating taurine-, caffeine-, and phosphatidylserine-containing supplementation in professional football players.

Participants in the validation cohort will be randomly assigned to receive either placebo or a phosphatidylserine-containing multi-ingredient supplement containing taurine, caffeine, and phosphatidylserine. Phosphatidylserine will be provided at a dose of 600 mg per day. The supplementation period will last 14 days. The placebo will be matched as closely as possible in appearance, number of units, packaging, and administration schedule.

The main aim of the study is to determine whether baseline characteristics can help identify players who are more likely to respond positively to the supplementation protocol. The multidimensional responder profile will include predefined domains related to physical performance and fatigue resistance, cognitive and mental fatigue-related outcomes, recovery/readiness-related outcomes, and selected football-specific perceptual-cognitive performance.

Before and after the supplementation period, participants will complete non-invasive assessments. These may include 30 m sprint performance, simple or choice reaction time, computerized cognitive tasks, mental fatigue ratings, heart rate variability indices such as LnRMSSD, wellness/readiness questionnaires, sleep quality, perceived fatigue, and selected football-specific performance variables where available.

The perceptual-cognitive domain may include football-specific decision-making accuracy, response time, tactical inhibitory decision-making under cognitive load, situational awareness, visual search-related variables, and selected field-transfer outcomes where available. These measures will be used to explore whether players who respond favorably in physical or recovery-related domains also show favorable responses in cognitive fatigue resistance, decision-making, or perceptual-cognitive football performance.

No blood, saliva, urine, genetic material, or other biological samples will be collected. All assessments will be non-invasive. The validation cohort will test whether responder profiles developed from previous trials can be applied to an independent group of professional football players. The study may support a more individualized approach to performance nutrition by identifying whether baseline autonomic, cognitive, fatigue-related, recovery-related, or perceptual-cognitive characteristics are associated with a greater likelihood of response to phosphatidylserine-containing multi-ingredient supplementation.

• Study Type: Interventional
• Enrollment (Estimated): 65
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Krzysztof Maciej Mizera, PhD; Phone Number: +48508356718; Email: krzysztofmizera@o2.pl

Study Locations

• Poland
  • Krakow, Poland
    • Professional Football Training Center
    • Contact: Krzysztof Mizera, PhD; Phone Number: +48508356718; Email: krzysztofmizera@o2.pl
  • Lodz, Poland, 01-043
    • Professional Football Training Center
    • Contact: Krzysztof Mizera, PhD; Email: krzysztofmizera@o2.pl
  • Warsaw, Poland, 01-043
    • Professional Football Training Center
    • Contact: Krzysztof Mizera, PhD; Email: krzysztofmizera@o2.pl
    • Contact: Email: krzysztofmizera@o2.pl
    • Principal Investigator: Krzysztof MIZERA, PhD

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Male professional or highly trained football players aged 18-36 years.
• Regular participation in structured football training and team activities.
• Minimum of 5 years of structured football training experience.
• Regular involvement in club training during the study period.
• Medical clearance or no known contraindications to high-intensity exercise testing.
• Ability to complete sprint, reaction-time, cognitive-fatigue, heart-rate-variability, wellness/readiness, and selected football-specific perceptual-cognitive assessments where available.
• Willingness to maintain usual diet and training habits during the study period.
• Willingness to avoid additional ergogenic supplements outside the study protocol during the intervention.
• Willingness to follow caffeine restrictions before testing sessions.
• Written informed consent provided before participation.

Exclusion Criteria:

• Current musculoskeletal injury or illness preventing full participation in training or testing.
• Musculoskeletal injury within the previous 3 months that may affect sprint, football-specific performance, or perceptual-cognitive testing.
• Cardiovascular, metabolic, neurological, psychiatric, or other chronic disease that may affect safety or study outcomes.
• Diagnosed sleep disorder.
• Use of medication affecting heart rate, autonomic nervous system function, sleep, cognition, or exercise performance.
• Known hypersensitivity or intolerance to caffeine, taurine, phosphatidylserine, or any supplement ingredient.
• Regular use of ergogenic supplements that cannot be discontinued before and during the study period.
• Smoking or regular use of nicotine products.
• Participation in another interventional study during the same period.
• Inability to comply with supplementation, monitoring, or testing procedures.
• Failure to provide written informed consent.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo; Participants assigned to this arm will receive placebo capsules for 14 consecutive days. Placebo capsules will be matched to the active supplement in appearance, number, packaging, and administration schedule.	Other: Placebo; Placebo capsules matched to the active supplements in appearance, number, packaging, and administration schedule. Participants will receive placebo capsules for 14 consecutive days.
Experimental: TCP-600 Supplementation; Participants assigned to this arm will receive a multi-ingredient supplement containing taurine, caffeine, and phosphatidylserine 600 mg/day for 14 consecutive days.	Dietary supplement: TCP-600 Supplementation; A multi-ingredient dietary supplement containing taurine 1500 mg/day, caffeine 200 mg/day, and phosphatidylserine 600 mg/day. Participants will receive the supplement for 14 consecutive days.
Active Comparator: Taurine + Caffeine; Participants assigned to this arm will receive taurine 1500 mg/day plus caffeine 200 mg/day for 14 consecutive days.	Dietary supplement: Taurine + Caffeine; A dietary supplement containing taurine 1500 mg/day and caffeine 200 mg/day. Participants will receive the supplement for 14 consecutive days.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of Participants Classified as Multidimensional Responders After 14 Days	Proportion of participants classified as multidimensional responders after 14 days of supplementation. A multidimensional responder will be defined as a participant meeting the predefined response criterion in at least two of four domains: physical performance/fatigue resistance, cognitive fatigue-related performance, recovery/readiness, and football-specific perceptual-cognitive performance. The outcome will be reported as the percentage of participants classified as multidimensional responders in each group. Unit of Measure: percentage of participants	Baseline to post-intervention after 14 days of supplementation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in 30 m Sprint Time	Change in 30 m sprint performance from baseline to post-intervention testing. Sprint time will be measured using electronic timing gates. Participants will perform three maximal 30 m sprint trials separated by standardized recovery periods, and the best valid trial will be used for analysis.	Baseline to post-intervention after 14 days of supplementation
Change in Cognitive Fatigue Task Reaction Time	Change in reaction time during the computerized cognitive fatigue task from baseline to post-intervention testing after 14 days of supplementation. Reaction time will be measured during the predefined cognitive task performed under cognitive load. The outcome will be reported as the mean change in reaction time from baseline to post-intervention testing. Lower values indicate faster cognitive responses. Unit of Measure: milliseconds	Baseline to post-intervention after 14 days of supplementation
Change in Perceived Mental Fatigue VAS Score	Change in perceived mental fatigue from baseline to post-intervention testing after 14 days of supplementation. Perceived mental fatigue will be assessed using a 0-10 visual analogue scale, where 0 indicates no perceived mental fatigue and 10 indicates maximal perceived mental fatigue. The outcome will be reported as the mean change in score from baseline to post-intervention testing. Higher scores indicate greater perceived mental fatigue. Unit of Measure: points on a 0-10 scale	Baseline to post-intervention after 14 days of supplementation.
Change in Final 3-Day Mean LnRMSSD	Change in heart rate variability from baseline monitoring to the final 3 days of supplementation. Heart rate variability will be expressed as the natural logarithm of the root mean square of successive RR interval differences. Morning HRV will be recorded under standardized resting conditions. The outcome will be reported as the mean change in final 3-day mean LnRMSSD compared with the baseline monitoring period. Unit of Measure: ln(ms)	Baseline monitoring period to final 3 days of supplementation.
Change in Readiness-to-Train Rating Scale Score	Change in self-reported readiness to train from baseline monitoring to the final 3 days of supplementation. Readiness to train will be assessed using a single-item readiness-to-train rating scale scored from 1 to 10, where 1 indicates very poor readiness and 10 indicates excellent readiness. The outcome will be reported as the mean change in readiness-to-train score from the baseline monitoring period to the final 3-day supplementation period. Higher scores indicate greater perceived readiness to train. Unit of Measure: points on a 1-10 scale	Baseline monitoring period to final 3 days of supplementation.
Change in Hooper and Mackinnon Wellness Questionnaire Fatigue Item Score	Change in self-reported fatigue from baseline monitoring to the final 3 days of supplementation. Fatigue will be assessed using the fatigue item of the Hooper and Mackinnon wellness questionnaire. The item is scored on a 1-7 scale. The outcome will be reported as the mean change in fatigue item score from the baseline monitoring period to the final 3-day supplementation period. Higher scores indicate greater perceived fatigue. Unit of Measure: points on a 1-7 scale	Baseline monitoring period to final 3 days of supplementation.
Area Under the Receiver Operating Characteristic Curve for the Predefined Responder Model	Predictive performance of the predefined responder model in the independent validation cohort will be assessed using the area under the receiver operating characteristic curve. The model will compare predicted responder status with observed multidimensional responder status after 14 days of supplementation. Higher values indicate better discrimination. Unit of Measure: area under the curve	Post-intervention after 14 days of supplementation.
Number of Participants With Supplement-Related Adverse Events	Number of participants reporting at least one supplement-related adverse event during the 14-day supplementation period. Participants will be asked to report gastrointestinal symptoms, sleep disturbances, headache, palpitations, nervousness, or any other unusual symptoms. Unit of Measure: participants	During the 14-day supplementation period
Change in Football-Specific Video Decision-Making Task Response Time	Change in response time during the football-specific video decision-making task from baseline to post-intervention testing after 14 days of supplementation. Response time will be measured as the time from presentation of the decision prompt to participant response. The outcome will be reported as the mean change in response time from baseline to post-intervention testing. Lower values indicate faster football-specific decision-making. Unit of Measure: milliseconds	Baseline to post-intervention after 14 days of supplementation.
Change in Football-Specific Video Decision-Making Task Accuracy	Change in football-specific decision-making accuracy from baseline to post-intervention testing after 14 days of supplementation. Decision-making accuracy will be assessed using a football-specific video decision-making task. Participants will view standardized football-specific scenarios and select the most appropriate tactical decision. The outcome will be reported as the mean change in the percentage of correct decisions from baseline to post-intervention testing. Higher values indicate better football-specific decision-making accuracy. Unit of Measure: percentage of correct decisions	Baseline to post-intervention after 14 days of supplementation.
Change in Eye-Tracking Time to First Fixation on the Optimal Tactical Option	Change in visual search behavior from baseline to post-intervention testing after 14 days of supplementation. Visual search behavior will be assessed using eye-tracking during the football-specific video decision-making task. Time to first fixation will be defined as the time from scenario onset to the first fixation on the predefined optimal tactical option. The outcome will be reported as the mean change in time to first fixation from baseline to post-intervention testing. Lower values indicate faster visual orientation toward the optimal tactical option. Unit of Measure: milliseconds	Baseline to post-intervention after 14 days of supplementation.

Collaborators and Investigators

• Sponsor: Vizja University in Warsaw

Study record dates

Study Major Dates

• Study Start (Estimated): August 1, 2026
• Primary Completion (Estimated): August 1, 2026
• Study Completion (Estimated): August 1, 2026

Study Registration Dates

• First Submitted: July 4, 2026
• First Submitted That Met QC Criteria: July 13, 2026
• First Posted (Actual): July 17, 2026

Study Record Updates

• Last Update Posted (Actual): July 17, 2026
• Last Update Submitted That Met QC Criteria: July 13, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Recovery; Soccer; Decision-making; Phosphatidylserine; Heart rate variability; Caffeine; Sports nutrition; Taurine; Reaction time; Mental fatigue; Football players; Responder analysis; LnRMSSD; Individual responsiveness; Perceptual-cognitive performance
• Additional Relevant MeSH Terms: Behavioral Symptoms; Fatigue; Pathological Conditions, Signs and Symptoms; Behavior; Signs and Symptoms; Mental Fatigue; Sulfur Compounds; Organic Chemicals; Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Hydrocarbons, Acyclic; Hydrocarbons; Alkaloids; Purinones; Purines; Alkanes; Alkanesulfonic Acids; Sulfonic Acids; Sulfur Acids; Xanthines; Caffeine; Taurine
• Other Study ID Numbers: VIZJA-TCP600-RESP-2026

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be publicly shared due to participant confidentiality and the small, potentially identifiable nature of the professional athlete sample. Aggregated results may be reported in publications. Selected anonymized analysis outputs may be made available from the corresponding author upon reasonable request, where ethically and legally appropriate.

Drug and device information, study documents

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