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NCT Number: NCT07219498

Effects of a 5-Week Probiotic Supplementation Intervention on Markers of Delayed Onset Muscle Soreness

The purpose of this study is to evaluate how probiotic supplementation (PS) influences post-exercise recovery in healthy, physically active young adults. Researchers aim to determine if the Lactobacillus casei probiotic strain reduces symptoms of delayed onset muscle soreness (DOMS) based on perceived muscle soreness, pressure pain threshold, and power output following exercise induced muscle damage (EIMD).

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Key information

Conditions

Exercise Induced Muscle Damage Delayed Onset Muscle Soreness (DOMS)

Age range

18 year–30 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Minnesota

Minneapolis, Minnesota, 55455, United States

Location status: Recruiting

Location contact

Jakob Fischer

CONTACT

[email protected]

507-236-8051

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • complete a minimum of 150 minutes a week of at least moderate intensity exercise in either an endurance-based or resistance-based training style based on a self-reported physical activity over the past month
  • good general health with no injuries or health conditions that would affect physical activity
  • willing to abstain from consistent NSAID use and other probiotic supplements over the course of this study

Exclusion criteria

  • known musculoskeletal injuries or physical limitations that could interfere with performing the designated physical activity required
  • underlying conditions that could place them at an increased risk during exercise such as cardiovascular, respiratory, or metabolic diseases
  • currently take a probiotic supplement, are prescribed and taking an antibiotic during the intervention, or report using NSAIDs or steroids within the recovery time window
  • report using an NSAID more than twice a week on a regular basis

Treatment and study plan

Lactobacillus casei

Dietary Supplement

Probiohealth is the manufacturer of this strain and they use a stringent quality control program that utilizes a multi point product variability check system.

Placebo Capsule(s)

Other

The brand name of placebo capsules that will be used in this study is Magic Bullet Placebo Capsules. This placebo is manufactured by Progressive Placebo as stated on the product label.

Primary outcomes

  1. Change in perceived muscle soreness

    Time frame: From baseline to post 5-week intervention

    Visual Analog Scale for perceived muscle soreness Each number on the scale will be designated with a descriptive word that corresponds to the soreness level they are experiencing. The scale will be laid out in order of increasing muscle soreness with "1" representing no pain.

  2. Change in pressure pain threshold (PPT)

    Time frame: From baseline to post 5-week intervention

    Calf pressure pain threshold (PPT) will be assessed by placing marks on the medial condyle of the femur and the posterior of the medial malleolus. The researcher will place the algometer on the muscle belly exactly halfway between the two marks. Volunteers will be instructed to specify when the first onset of pain occurs as the researcher gradually applies pressure. Quadricep measurements will involve the participant lying in the supine position where marks will be made on the anterior inferior iliac spine and the top of the patella so the researchers can once again find a point exactly halfway between these two locations to apply the algometer. Participants will be instructed to verbally indicate to the researcher when the onset of pain occurs as pressure is applied.

  3. Change in countermovement jump assessment (CMJ) performance recovery

    Time frame: From baseline to post 5-week intervention

    The researchers will demonstrate and instruct volunteers to "Stand upright with their hands above their head. When you are ready, bend your knees and stick your hips back while keeping your hands to your hips. Jump as high as possible and land softly." Participants will perform three CMJs separated by 60 seconds. Jump height will be recorded in cm and the highest value will be recorded.

Study contacts

Contact information is provided by the study sponsor or research team.

Jakob Fischer

CONTACT

[email protected]

507-236-8051

Sponsors and collaborators

Lead sponsor

University of Minnesota

Other

Registry information

Important dates

Study start
2026
Primary completion
2026
Study completion
2026
First posted
Oct 22, 2025
Registry last updated
May 4, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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