The Effects of Acute Nitrate and Caffeine Co-ingestion on Discipline-Specific Exercise Performance. | NCT07748416

NCT07748416

Overview

NCT ID: NCT07748416
Lead Sponsor: Poznan University of Physical EducationOTHER
Official Title: The Acute Effects of Dietary Nitrate (Beetroot Juice), Caffeine, and Their Combination on Discipline-Specific Exercise Performance, Lactate Kinetics, and Physiological Responses in Trained Functional Fitness Athletes and Elite Junior Swimmers.
Brief Summary: The purpose of this study is to investigate the acute, separate, and combined ergogenic effects of dietary nitrate (beetroot juice, BJ) and caffeine (CAF) supplementation on discipline-specific athletic performance. The project employs a double-blind, randomized, placebo-controlled, four-arm crossover design. It evaluates two highly distinct, heterogeneous populations of athletes: (A) adult high-intensity functional training (HIFT/CrossFit/Hyrox) competitors performing the standardized Hyrox Physical Fitness Test (P'F'T), and (B) elite junior competitive swimmers (National Team members) performing a progressive 8 × 100 m swimming test. The study will assess physical performance, lactate kinetics, subjective exertion, biochemical indices, psychological metrics, and gastrointestinal tolerance.

Status and Timeline

Status: Not yet recruiting
Last Update Posted: Aug 5, 2026Actual
Start Date: Oct 1, 2026Estimated
Primary Completion Date: Jun 30, 2029Estimated

Participation Criteria

Ages Eligible for Study: Child (0-17)Adult (18-64)
Sexes Eligible for Study: All
Accepts Healthy Volunteers?: Yes
Eligibility Criteria: Inclusion Criteria:

A) Cohort A (HIFT / CrossFit / Hyrox):

Aged 18-45 years.

Minimum of 2 years of systematic HIFT/CrossFit/Hyrox training experience.

Performing >4 training sessions per week.

Ability to perform the HYROX Physical Fitness Test (P'F'T) and has participated in at least one official HYROX event.

Possession of a valid medical certificate proving eligibility for competitive sports.

B) Cohort B (Competitive Junior Swimmers):

Aged 16-19 years.

Active member of the Polish Junior National Swimming Team.

Minimum of 5 years of competitive swimming experience.

Current training volume of at least 8-10 pool training sessions per week.

Written informed consent obtained from both the participant and their legal guardian (for minors under 18).

C)Common Criteria for Both Cohorts:

No history of cardiovascular, respiratory, metabolic, or musculoskeletal disease contradicting high-intensity exercise or stimulant intake.

No known food allergies or adverse reactions to beetroot products or caffeine.

No current use of medications that alter nitrate/caffeine metabolism (e.g., proton pump inhibitors, antibiotics, phosphodiesterase inhibitors).

History of uneventful habituation to caffeine use during training/competition.

Willingness to abstain from dietary supplements, antibacterial mouthwashes, alcohol, and high-nitrate foods for 48 hours prior to each testing session.

Good general health and physical well-being.

Exclusion Criteria (Applicable to both cohorts):

Occurrence of acute musculoskeletal injury or trauma during the study period.

Any medical or health contraindications (including severe menstrual disorders, planned pregnancy, or breastfeeding).

Failure or refusal to strictly adhere to the dietary, supplementation, and exercise testing protocols.

Study Plan

Study Type: Interventional
Phase: Not Applicable
Enrollment: 112Estimated
Primary Purpose: Basic Science
Allocation: Randomized
Interventional Model: Crossover Assignment
Masking

Contacts and Locations

Central Contacts: Natalia Główka, PhDContact
glowka@awf.poznan.pl

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