Does the Development of the Repeated Bout Effect Depend on Oxidative Stress and Inflammation? (ANTI-RBE)

Eccentric exercise, particularly when novel and strenuous, can cause soreness and inflammation, impairing subsequent exercise performance. These performance decrements are attributable to oxidative stress and inflammation. Interestingly, a single bout of eccentric exercise can confer protective effects, ameliorating the negative consequences in subsequent bouts. This is termed the repeated bout effect (RBE), which would be of interest to athletes considering the detrimental effects of strenuous eccentric exercise. Athletes regularly consume supplements in hope of attenuating the performance decrements after strenuous eccentric exercise

. However, considering the dose-response relationship between the initial performance decrement and the magnitude of the RBE , supplements may diminish the obtainment of the RBE. This notion remains untested, and so the proposed project is a double-blind, placebo-controlled, parallel group study aiming to assess the effects of acute vitamin C and ibuprofen supplementation on the development of the RBE. These two supplements were chosen as they are most frequently and successfully used in the literature to target oxidative stress (vitamin C) and inflammation (ibuprofen). Additionally, these doses (and the timing of supplements) were chosen to mimic protocols reporting beneficial effects

Study Overview

• Status: Recruiting
• Conditions: Exercise Recovery
• Intervention / Treatment: Dietary supplement: Intervention; Dietary supplement: Control

• Study Type: Interventional
• Enrollment (Estimated): 52
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Bath, United Kingdom
    • Recruiting
    • University of Bath
    • Contact: Max Davis; Phone Number: 07950449960; Email: md959@bath.ac.uk

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• 18 - 45 years of age
• BMI 18.5 - 29.9 kg/m2
• Able to perform 20-minutes of bench stepping exercise
• Capable and willing to provide consent (oral and written)

Exclusion Criteria:

• Familiarised with bench stepping exercise procedures
• Not cleared for exercise by health questionnaires or physical activity readiness questionnaire
• Participants exhibiting any alteration in clinical inflammation parameters due to other cause
• Participants currently being prescribed any anti-inflammatory medications

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Intervention; Vitamin C and Non-steroidal anti-inflammatory drug	Dietary supplement: Intervention; 1,000 mg Vitamin C and 400 mg non-steroidal anti-inflammatory drug every 8-h for 48-h
Placebo Comparator: Control; Identical Placebo	Dietary supplement: Control; Identical maltodextrin tablet. Appearance and weight matched

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Muscle Function	Jump height calculated through flight time	Baseline and post exercise (2 hours, 1 day, 7 day)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Muscle Function	Peak power quantified using a Keiser Leg Press	Baseline and post exercise (2 hours, 1 day, 7 day)
Muscle Function	Peak force quantified using a Keiser Leg Press	Baseline and post exercise (2 hours, 1 day, 7 day)
Muscle Function	Peak velocity quantified using a Keiser Leg Press	Baseline and post exercise (2 hours, 1 day, 7 day)
Creatine Kinase	Plasma Creatine Kinase	Baseline and immediately, 1-h (hour)-, 2-h-, 24-h-,and 48-hours-post-exercise

Collaborators and Investigators

• Sponsor: University of Bath

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2025
• Primary Completion (Estimated): February 28, 2027
• Study Completion (Estimated): February 28, 2027

Study Registration Dates

• First Submitted: March 4, 2026
• First Submitted That Met QC Criteria: March 13, 2026
• First Posted (Actual): March 16, 2026

Study Record Updates

• Last Update Posted (Actual): March 16, 2026
• Last Update Submitted That Met QC Criteria: March 13, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Investigative Techniques; Methods
• Other Study ID Numbers: 11104-14846

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES

Drug and device information, study documents

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