Effects of Watermelon Juice on Heart Rate Recovery and Post-exercise Muscle Soreness

January 16, 2026 updated by: San Diego State University
The purpose of this study was to determine the effects of a pre-exercise, single practical dose of watermelon juice, Gatorade, sugar water or water on heart rate recovery, blood lactate levels, and 24-hour post exercise muscle soreness.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

27

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United States
    • California
      • San Diego, California, United States, 92182-7251
        • Recruiting
        • Exercise and Nutritional Sciences, SDSU
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

21 years to 50 years (Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • ages of 21-50 healthy adults

Exclusion Criteria:

  • Suffering from injury
  • Chronic inflammatory conditions
  • Required dietary supplement use
  • Required medication which affects blood pressure
  • Smoking
  • Pregnant woman
  • Allergy to watermelon

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Water
Other: Water
Subject drinks 355ml of water 1 hour prior to submaximal exercise
Experimental: Watermelon juice
Other: Watermelon juice
Subject drinks 355ml of watermelon juice 1 hour prior to submaximal exercise
Active Comparator: Sport drink
Other: Sport drink
Subject drinks 355ml of Gatorade 1 hour prior to submaximal exercise
Active Comparator: Sugar water
Other: Sugar water
Subject drinks 355ml of sugar water (22.5g) 1 hour prior to submaximal exercise

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change of heart rate after submax exercise
Time Frame: Baseline and every minute post exercise for a maximum 20 minutes post exercise.
The participants then were fitted to cycling shoes and familiarized with the Lode cycle ergometer (Lode Excalibur Sport, Groningen, Netherlands), completed a warm-up and were asked to perform a criterion work rate trial ending at 80% predicted HRmax. Heart rate was recorded every minute post exercise for a maximum of 20 minutes post exercise.
Baseline and every minute post exercise for a maximum 20 minutes post exercise.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

San Diego State University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 1, 2016

Primary Completion (Estimated)

December 1, 2028

Study Completion (Estimated)

December 1, 2028

Study Registration Dates

First Submitted

December 11, 2017

First Submitted That Met QC Criteria

December 14, 2017

First Posted (Actual)

December 21, 2017

Study Record Updates

Last Update Posted (Actual)

January 21, 2026

Last Update Submitted That Met QC Criteria

January 16, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2487100

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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