Short-term Effects of Broccoli-derived Glucoraphanin on Recovery From Eccentric Muscle Damage

SHORT-TERM EFFECTS OF BROCCOLI-DERIVED GLUCORAPHANIN ON RECOVERY FROM ECCENTRIC MUSCLE DAMAGE: A DOUBLE-BLIND RANDOMIZED CROSSOVER STUDY

Eccentric exercise induces muscle damage and delay functional recovery. Broccoli-derived glucoraphanin (a sulforaphane precursor that activates Nrf2 defenses) may aid repair; however, its short-term effects in humans remains unknown. This study aims to evaluate whether short-term supplementation with broccoli-derived glucoraphanin will improve recovery from exercise-induced muscle damage. In a randomized, double-blind, placebo-controlled crossover design, fifteen participants will consume either high-glucoraphanin broccoli powder (320 μg) or placebo for one week, followed by elbow flexor eccentric exercise and continued supplementation. Strength, soreness, creatine kinase (CK), range of motion (ROM), arm girths, and ultrasound-assessed muscle and tendon morphology will be measured at baseline, immediately post-exercise, and at 48 and 96 hours post-exercise.

Study Overview

• Status: Not yet recruiting
• Conditions: Healthy
• Intervention / Treatment: Dietary supplement: broccoli powder consumption; Dietary supplement: Placebo (no broccoli-derived bioactives)

• Study Type: Interventional
• Enrollment (Estimated): 17
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• no resistance training experience in the past 6 months, no arm injuries in the past 2 years, no illnesses in the month prior to data collection, and no known allergies to broccoli or other cruciferous vegetables.

Exclusion Criteria:

• incomplete participation.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: male volunteers aged 18-35 years

Dietary supplement: broccoli powder consumption; Participants underwent two separate sessions of muscle-damaging exercise targeting the elbow flexors: (1) following seven days of broccoli powder consumption (condition X), and (2) following an equivalent placebo regimen (condition Y). The broccoli supplementation consisted of 10 g of broccoli powder [a freeze-dried glucoraphanin-rich broccoli powder (99.5% broccoli and 0.5% mustard seed)] dissolved in 125 mL of boiling water, providing 320 μg of glucoraphanin per serving. It was consumed when still hot/warm once daily for seven days before and for four days following the eccentric exercise protocol. The placebo powder, matched in appearance and preparation, contained no broccoli-derived bioactives.; Dietary supplement: Placebo (no broccoli-derived bioactives); The placebo powder, matched in appearance and preparation, contained no broccoli-derived bioactives.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Peak torque, Nm/s	Exercise induced damage marker, isokinetic and isometric knee extension	At baseline, immediately post-exercise, and at 48 hours, and at 96 hours post-exercise.
Range of motion, degree	Exercise induced damage marker, elbow extension and flexion	At baseline, immediately post-exercise, and at 48 hours, and at 96 hours post-exercise.
Arm girth, mm	Exercise induced muscle damage marker, arm relaxed and fully flexed	At baseline, immediately post-exercise, and at 48 hours, and at 96 hours post-exercise.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Soreness, points	exercise induced damage marker, biceps brachii, 10-point visual analogue scale with 0 indicating no soreness and 10 indicating intolerably intense soreness.	At baseline, immediately post-exercise, and at 48 hours, and at 96 hours post-exercise.
Creatine kinase, IU/L	Exercise induced muscle damage marker in venous blood	At baseline, immediately post-exercise, and at 48 hours, and at 96 hours post-exercise.

Collaborators and Investigators

• Sponsor: Lithuanian Sports University

Study record dates

Study Major Dates

• Study Start (Estimated): February 15, 2026
• Primary Completion (Estimated): March 15, 2026
• Study Completion (Estimated): March 31, 2026

Study Registration Dates

• First Submitted: September 15, 2025
• First Submitted That Met QC Criteria: January 22, 2026
• First Posted (Actual): January 28, 2026

Study Record Updates

• Last Update Posted (Actual): January 28, 2026
• Last Update Submitted That Met QC Criteria: January 22, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: MNLKIN(M)-2024-574

Drug and device information, study documents

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