The Effect of a Citrus Extract on Exercise Performance in Moderately Trained Athletes

Establishing the Effect of Long-term Citrus Extract Supplementation on Exercise-specific Performance in Moderately Trained Athletes

In this study, the effect of citrus extract on exercise performance will be investigated. The study consists of three groups: one group will receive a high dose citrus extract, one group will receive a low dose citrus extract and the last group will receive a placebo. After four and eight weeks the effects on performance are measured through a Wingate cycling test. It is expected that exercise performance will increase in the citrus extract groups, compared to the placebo group.

Study Overview

• Status: Completed
• Conditions: Exercise Performance
• Intervention / Treatment: Dietary supplement: citrus extract; Other: placebo

• Study Type: Interventional
• Enrollment (Actual): 93
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Netherlands
  • Limburg
    • Sittard, Limburg, Netherlands, 6135LG
      • High Performance Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 35 years (ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• healthy idividuals
• Participants are amateur or (semi-) professional athletes in resistance or interval sports (engage in >4 hours of intense physical activity per week).

Exclusion Criteria:

• Use of creatine supplements and/or anabolic steroids.
• Allergy to test product/placebo
• Allergy to citrus fruits
• BMI lower than 18 or higher than 30
• Recent muscle injury in less than one month before the start of the study.
• Cardiovascular complications
• Use of medication that may interfere with the study results
• Administration of investigational drugs or participation in any scientific intervention study which may interfere with this study (to be decided by the principle investigator), in the 180 days prior to the study.
• Abuse of products; alcohol (> 20 alcoholic units per week) and drugs.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: OTHER
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: TRIPLE

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
EXPERIMENTAL: high dose citrus extract; this group will receive a high dose (500mg/day) of the citrus extract for 8 weeks	Dietary supplement: citrus extract; Participants will receive either a low or high dose citrus extract
EXPERIMENTAL: low dose citrus extract; this group will receive a low dose (400mg/day) of the citrus extract for 8 weeks	Dietary supplement: citrus extract; Participants will receive either a low or high dose citrus extract
PLACEBO_COMPARATOR: placebo; this group will receive a placebo (500mg maltodextrin per day) for 8 weeks	Other: placebo; participants will receive 500mg of maltodextrin

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
peak force output Wingate	Peak force output in Watts during a high intensity repeated sprint cycling exercise	8 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
jumping height	jumping height in cm measured during a vertical jump exercise	8 weeks
peak force output Handgrip	Peak force output in Watts during a handgrip strength test	8 weeks
force output Jump	force output in W measured during a vertical jump exercise	8 weeks
anaerobic capacity	total amount of power (W) generated in the first 30 seconds of the the triple Wingate cycle test	8 weeks
running time	running time in minutes and seconds measured over 1600m	8 weeks

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
lactate	post-exercise blood lactate in mmol/L after triple Wingate cycle exercise test	8 weeks

Collaborators and Investigators

• Sponsor: BioActor
• Investigators: Principal Investigator: Freddy Troost, Dr., Maastricht University

Publications and helpful links

General Publications

• van Iersel LE, Stevens YR, Conchillo JM, Troost FJ. The effect of citrus flavonoid extract supplementation on anaerobic capacity in moderately trained athletes: a randomized controlled trial. J Int Soc Sports Nutr. 2021 Jan 6;18(1):2. doi: 10.1186/s12970-020-00399-w.

Study record dates

Study Major Dates

• Study Start (ACTUAL): April 13, 2017
• Primary Completion (ACTUAL): April 6, 2018
• Study Completion (ACTUAL): April 6, 2018

Study Registration Dates

• First Submitted: January 30, 2017
• First Submitted That Met QC Criteria: February 2, 2017
• First Posted (ESTIMATE): February 7, 2017

Study Record Updates

• Last Update Posted (ACTUAL): July 10, 2020
• Last Update Submitted That Met QC Criteria: July 8, 2020
• Last Verified: July 1, 2020

More Information

Terms related to this study

• Keywords: nutrition; sports; polyphenols; performance
• Other Study ID Numbers: HES_PER_002

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