Kefir Versus Milk on Time-Trial Performance in Masters Athletes (KVM)

December 8, 2023 updated by: Lindenwood University

Effect of Flavored Kefir Versus Flavored Milk on Time-Trial Performance in Endurance Master Athletes

The purpose of this study is to determine the effects of added probiotic cultures to a carbohydrate + protein recovery beverage compared to a similar recovery beverage without probiotic cultures, in its ability to impact endurance performance, perceived ratings of gastrointestinal symptoms and markers of inflammation and intestinal damage.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

In a randomized, crossover fashion, the investigators will assess changes in exercise performance, gastrointestinal symptom rating scale scores, as well as interleukin-6 and intestinal fatty-acid binding protein levels following consumption of either water, kefir or flavored milk.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
11

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Locations

  • United States
    • Missouri
      • Saint Charles, Missouri, United States, 63301
        • Exercise and Performance Nutrition Laboratory

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Provide voluntary signed and dated informed consent.
  • Be in good health as determined by medical history and routine blood chemistries.
  • Normotensive (seated, resting systolic blood pressure < 140 mm Hg and diastolic blood pressure < 90 mm Hg. If the first measurement is slightly elevated above these limits, the subject will be given a brief (5 minute) rest period, and two more measurements will be taken. The average of all three measurements will be used to determine eligibility.
  • Normal seated, resting heart rate (< 90 beats per minute).
  • Age between 40 and 75 years of age
  • Body Mass Index <30 kg/m2 or Body Fat <30% for females and <25% for males
  • Performing aerobic exercise > 150 mins/week and training for at least 3 years
  • Well-trained will be defined as athletes that meet two of the four following criteria: training frequency is 3-7 sessions/week; duration of training sessions is 60-240 min; training background is at least 3 y; race frequency is at least once a year.

Exclusion Criteria:

  • Individuals currently diagnosed or being treated for any cardiac, respiratory, endocrine, psychiatric, musculoskeletal, renal, hepatic, neuromuscular or metabolic disease or disorder that in the judgement of the study participant's personal physician or research nurse that will preclude their safe participation or will contraindicate quality control over the collected data
  • Individuals currently diagnosed with or are being treated for celiac disease, lactose intolerance, digestive insufficiencies or other gastrointestinal complications such as irritable bowel syndrome, ulcerative colitis, etc.

Alcohol consumption (more than 2 standard alcoholic drinks per day or more than 10 drinks per week) or drug abuse or dependence.

  • Smokers or individuals who have quit smoking within the last 6 months
  • Participants that are unwilling to refrain from caffeine, nicotine, and alcohol intake for 12 hours prior to each study visit.
  • Known sensitivity to any ingredient in the test formulations as listed in the Nutrition Facts label.
  • Individuals who are determined to be on a ketogenic diet.
  • Individuals who are cognitively impaired and/or who are unable to give informed consent.
  • Participants that are unwilling to refrain from taking biotin at a minimum of 72 hours before visit 3 through the end of the study due to potential interference with laboratory analyses.
  • Individuals taking a medication known to impact digestive function or hormonal functions that may impact how our body digests, absorbs or metabolizes nutrients
  • Individuals that are currently taking a probiotic or a dietary supplement that may impact digestive function or hormonal function that may impact how our body digests, absorbs or metabolizes nutrients
  • Participants that are unwilling to refrain from fermented foods and yogurt, as well as maintain normal consumption levels of prebiotics throughout the study.
  • Pregnant women, women trying to become pregnant, or nursing women.
  • Individuals who indicate they are actively restricting calories or attempting to lose weight.
  • Participants that are unwilling to keep their self-directed training protocols the same throughout the course of the study
  • Participants that are unwilling to wear the same shoes and similar clothing for all testing visits.
  • Individuals who participate in aerobic exercise < 2 days/week or have been aerobically training < 3 years
  • Individuals that do not meet the criteria to be defined as well-trained
  • Unwillingness to intake a supplement or follow the study protocol
  • Any other condition which in the investigator's opinion may adversely affect the subject's ability to complete the study or its measures or which may pose a significant risk to the subject.

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: Other
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Placebo Comparator: Water
Other: Water
340 mL plain tap water consumed immediately following glycogen depleting exercise
Experimental: Flavored Kefir
1% Lowfat Kefir manufactured by Lifeway Kefir and containing 18 g of CHO, 10 g of protein, and 2 g of fat
Other: Flavored Kefir
320 mL kefir consumed immediately following glycogen depleting exercise
Active Comparator: Flavored Milk
1% Lowfat Milk manufactured by Prairie Farms and containing 24 g of CHO, 8 g of protein, and 2.5 g of fat
Other: Flavored Milk
240 mL flavored milk consumed immediately following glycogen depleting exercise

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Aerobic Performance Times
Time Frame: Through study completion, an average of 3 weeks
5 kilometer running time-trial on a curved, non-motorized treadmill
Through study completion, an average of 3 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Blood Interleukin-6
Time Frame: Through study completion, an average of 3 weeks
Blood interleukin-6 concentrations in response to intense exercise
Through study completion, an average of 3 weeks
Blood Intestinal fatty-acid binding protein
Time Frame: Through study completion, an average of 3 weeks
Blood Intestinal fatty-acid binding protein concentrations in response to intense exercise
Through study completion, an average of 3 weeks
Gastrointestinal Symptoms
Time Frame: Through study completion, an average of 3 weeks
Gastrointestinal Symptoms measured using the Gastrointestinal Symptoms Rating Scale (GSRS) in response to intense exercise. The scale asks 15 questions, and asks participants to rate their gastrointestinal symptoms on a 7 point scale with 0 being no discomfort at all and 7 being very severe discomfort. Lower total GSRS scores indicate a better outcome.
Through study completion, an average of 3 weeks

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Lindenwood University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Chad M Kerksick, PhD, Lindenwood 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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 7, 2023

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 15, 2023

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 15, 2023

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 16, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 8, 2023

First Posted (Estimated)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
December 11, 2023

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
December 11, 2023

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 8, 2023

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
December 1, 2023

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • IRB-23-71

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

The investigators do not plan to make IPD available to other researchers

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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