The Effect of Beetroot Juice on Muscle Strength and Muscle EMG Activity During Isokinetic Performance (NO Isokinetic)

Effects of Beetroot Juice Supplementation on Neuromuscular Activity and Isokinetic Strength and Power During Maximal Exercise

The primary aim of the current study is determine the effect of beetroot juice consumption on neuromuscular activation, isokinetic muscle strength and power

Study Overview

• Status: Completed
• Conditions: Muscle Strength; Isokinetic Test
• Intervention / Treatment: Dietary supplement: Beetroot juice; Dietary supplement: Placebo

Detailed Description

Participants completed two experimental sessions in a randomized, double-blind, placebo-controlled crossover design separated by a minimum 3-day washout period. Prior to each session, participants were instructed to avoid nitrate-rich foods, strenuous exercise, antibacterial mouthwash, chewing gum, and tooth brushing.

All testing sessions were performed in the morning following an overnight fast. Upon arrival, anthropometric measurements were obtained and participants consumed either a nitrate-rich beetroot juice supplement (highNO) or nitrate-depleted placebo (lowNO). Following a standardized 2-hour absorption period, surface EMG electrodes were placed on the vastus medialis oblique (VMO) and vastus lateralis oblique (VLO) muscles according to SENIAM guidelines. Capillary blood samples were collected before exercise and 3 minutes after the fatigue protocol for blood lactate assessment.

Participants then completed a standardized 10-minute warm-up followed by isokinetic testing using a Biodex dynamometer. Testing was performed on the dominant lower limb at angular velocities of 180°/s, 60°/s, and 240°/s. Three maximal repetitions were performed at 60°/s and 180°/s, while a 30-repetition fatigue protocol was completed at 240°/s. Outcome measures included peak torque, peak power, total work, torque-angle variables, EMG activity, and blood lactate concentration.

• Study Type: Interventional
• Enrollment (Actual): 13
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Poland
  • Greater Poland Voivodeship
    • Poznan, Greater Poland Voivodeship, Poland, 61-871
      • Akademia Wychowania Fizycznego

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• age ≥18 years,
• participation in at least three structured training sessions per week,
• absence of musculoskeletal injuries within the previous 12 months

Exclusion Criteria:

• smoking,
• any injury within the past year

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Beetroot juice; beetroot juice with high concentration of nitrates ( 800mg)	Dietary supplement: Beetroot juice; acute dose of beetroot juice
Placebo Comparator: Depleted Beetroot Juice; beetroot juice with low concentration of nitrates	Dietary supplement: Placebo; depleted nitrate beetroot juice

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The effect of beetroot juice ingestion on isokinetic strength	The aim of the present study was to examine the effects of acute ignestion of nitrate rich suplement compared with placebo on isokinetic muscle performance during knee extension and flexion tasks performed using an isokinetic dynamometer.	2 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The effect of Beetroot Juice consumption on EMG muscle activity	Neuromuscular activity was assessed using surface electromyography of the vastus medialis oblique and vastus lateralis oblique muscles while Isokinetic tests	2 hours

Collaborators and Investigators

• Sponsor: Poznan University of Physical Education
• Investigators: Principal Investigator: Robert Olek, Prof, Poznan University of Physical Education

Study record dates

Study Major Dates

• Study Start (Actual): May 15, 2025
• Primary Completion (Actual): May 15, 2025
• Study Completion (Actual): July 2, 2025

Study Registration Dates

• First Submitted: May 18, 2026
• First Submitted That Met QC Criteria: May 18, 2026
• First Posted (Actual): May 26, 2026

Study Record Updates

• Last Update Posted (Actual): May 26, 2026
• Last Update Submitted That Met QC Criteria: May 18, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: RMPN2021/JJ3

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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