Kefir Versus Milk on Time-Trial Performance in Masters Athletes

NCT06165523 | Completed

• 1 other identifier: IRB-23-71
• Study Type: interventional
• Target: 11
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Gastrointestinal Complication; Exercise Performance; Aerobic Endurance

Keywords

Kefir; Milk; Aerobic Endurance; Exercise Performance; Gastrointestinal Symptoms

Outcome Measures

Primary Outcomes (1)

• Aerobic Performance Times

  5 kilometer running time-trial on a curved, non-motorized treadmill

  Through study completion, an average of 3 weeks

Secondary Outcomes (3)

• Blood Interleukin-6

  Through study completion, an average of 3 weeks

• Blood Intestinal fatty-acid binding protein

  Through study completion, an average of 3 weeks

• Gastrointestinal Symptoms

  Through study completion, an average of 3 weeks

Study Arms (3)

Water

PLACEBO COMPARATOR

Water

Other: Water

Flavored Kefir

EXPERIMENTAL

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

Flavored Milk

ACTIVE COMPARATOR

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

Interventions

Water OTHER

340 mL plain tap water consumed immediately following glycogen depleting exercise

Water

Flavored Kefir OTHER

320 mL kefir consumed immediately following glycogen depleting exercise

Flavored Kefir

Flavored Milk OTHER

240 mL flavored milk consumed immediately following glycogen depleting exercise

Flavored Milk

Eligibility Criteria

• Age: 40 Years - 75 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• 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

Sponsors & Collaborators

• Lindenwood University: lead

Study Sites (1)

Exercise and Performance Nutrition Laboratory

Saint Charles, Missouri, 63301, United States

Location

MeSH Terms

Interventions

Water

Intervention Hierarchy (Ancestors)

Hydroxides; Alkalies; Inorganic Chemicals; Anions; Ions; Electrolytes; Oxides; Oxygen Compounds

Study Officials

• Chad M Kerksick, PhD

  Lindenwood University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Masking Details: Both participant and investigator are unmasked to treatment conditions
• Purpose: OTHER
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Randomized, crossover.

Study Record Dates

• First Submitted: November 16, 2023
• First Posted: December 11, 2023
• Study Start: March 7, 2023
• Primary Completion: August 15, 2023
• Study Completion: August 15, 2023
• Last Updated: December 11, 2023

Record last verified: 2023-12

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)