Influence of β-hydroxy β-methyl Butyrate (HMB)Supplementation on Post-operative Muscle Mass and Function in Female Athletes (FAKS-HMB)

February 26, 2026 updated by: Ashley A. Herda, Ph.D., CSCS*D, University of Kansas Medical Center
The proposed project will evaluate the musculoskeletal outcomes of quadriceps and hamstring muscle size and function following orthopedic knee surgery involving anterior cruciate ligament (ACL) repair or reconstruction. Currently, the research team collaborates with a team of orthopedic specialists at the University of Kansas Health System and monitor muscle size post-knee repair and follow the standard of care (SOC) practices of the licensed physical therapists (PT). The proposed project will include a randomized clinical trial to observe the muscular outcomes following the current SOC plus supplementation of calcium-β-hydroxy-β-methylbutyrate (caHMB) or placebo. CaHMB has been shown to improve rates of muscle protein synthesis while suppressing muscle protein breakdown in healthy adults. The use of caHMB has also provided evidence of muscular protection from atrophy during prolonged bed rest. This evidence supports the utility in clinically injured athletes that are subjected to disuse atrophy from the inability to bear weight or participate in typical daily physical activity. Additionally, matched for activity-related knee injuries, female athletes are more susceptible to incurring a significant injury due to a variety of genetic, hormonal, biological, anatomical, and biomechanical predispositions. Therefore, the proposed study will recruit approximately 30 females over the age of 18 that have sustained an injury to the ACL and will plan to undergo reconstructive knee surgery involving the ACL. Subjects will be monitored and measured prior to their surgical date (T0), at 2-weeks post operative (T1), and every 6-weeks until they are cleared to return to sport (T2-TRTS). Participants will be randomly assigned 1:1 in a double-blind manner to either an experimental (EXPHMB) or placebo (CONPLA) group. Doses will be provided to the participants in coded containers and will complete their dosing and a record log of intake for the duration of their rehabilitation. Three 3-day food, exercise, and health record logs will be collected to monitor nutritional intake, activity, and menstrual patterns at T0, T3, and TRTS. Participant's assessments will include body composition analysis via bioelectrical impedance analysis for total and segmental muscle and fat mass, skeletal muscle mass, and body fat percent. We will collect ultrasound images of the quadriceps and hamstrings of the operative-involved limb (OPIL) and non-operative limb (NOPL) limbs for muscle cross-sectional area (mCSA), thickness (mT), subcutaneous fat thickness (TFAT), and corrected echo intensity (EICOR) at all time points. Strength and functional assessments will occur upon entrance to the study (T0), and after loaded exercise is indicated by the practitioner (T3-TRTS) to the tolerance of the athlete. These assessments include maximal voluntary isometric contractions (MVIC) for leg extension and leg curl, standing balance tests, single-leg and double-leg jump assessment, and drop landing deviation, all on dual force plates. Data will be analyzed using multiple three-way analyses of variance [surgical leg (OPIL vs. NOPL) x treatment (EXPHMB vs. CONPLA) x time (T0 vs. T1 vs. T2 vs. T3 vs. T4 vs. T5 vs. TRTS) for the dependent variables. Significance is established at p≤0.05 and follow-up ANOVAS, T-tests, and post-hoc analyses will be conducted when significance is present. The evidence from this study will support the practitioners and coaches' abilities to maximize recovery and training outcomes, respectively, in previously injured female athletes.

Study Overview

Status

Status

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

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.

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 (Estimated)

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.
30

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.
  • Phase 2

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 Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Ashley Herda, PhD
  • Phone Number: 913-897-8618
  • Email: a.herda@ku.edu

Study Contact Backup

Study Locations

  • United States
    • Kansas
      • Overland Park, Kansas, United States, 66213
        • Recruiting
        • University of Kansas Health System
        • Contact:
        • Contact:
        • Principal Investigator:
          • Ashley A Herda, PhD

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

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Participant has provided written and dated informed consent to participate in the study.
  2. Participant is biological female between 18 and 45 years of age, inclusive.
  3. Participant intends to complete postoperative rehabilitation at affiliated physical therapy clinic.

Exclusion Criteria:

  1. Participant is currently consuming nutritional supplements or has recently (regularly) consumed nutritional supplements, other than multivitamins and minerals in <9 weeks prior to participation.
  2. Participant currently suffers from a sleep disorder and/or has a known history of (or is currently being treated for) clinical depression, eating disorder(s) or any other psychiatric condition(s) that might limit natural recovery from substantial injury.
  3. Participant has a history of orthopedic injury or surgery within the last year in the non-operative limb that may prevent them from completing the study procedures.
  4. Participant has history of previous injury or surgery in the operative limb.
  5. Participant has implants, hardware, devices, or other non-removable metal material in the body that would limit the accuracy of body composition assessments within the measurement area.
  6. Participant is participating in another clinical trial or has received an investigational product within thirty days prior to enrollment.
  7. Participant has a known allergy or sensitivity to any ingredient in the test product/s.
  8. Participant is pregnant as confirmed by a urine sample and hCG test.

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: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

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.
Experimental: CaHMB+Vitamin D3-Active Experimental
Participants will consume 3 g HMB with 2000 IU Vitamin D3 per day, split into two doses daily for the duration of the study, beginning 2 weeks prior to their surgical date. The first dose will be consumed 60 minutes prior to any at- home or outpatient physical therapy session and a second will be consumed immediately following the session. If a treatment day does not include any rehabilitation session, the participant will consume one dose in the morning prior to food consumption and the second dose approximately 90 minutes later.
Drug: CaHMB (Dietary supplement, not Drug)
The investigators will focus our effort, for the purposes of this study, on determining if adding an HMB supplement will stimulate positive outcomes and recovery of the quadriceps and hamstrings muscle architecture and function in females with ACL injury requiring surgical repair, more so than a placebo control.
Other Names:
  • Calcium HMB
  • Beta-hydroxy-beta-methylbutyrate
Placebo Comparator: Calcium Lactate-Control Placebo
Participants will consume inactive 510 mg Ca Lactate capsules per day, split into two doses daily for the duration of the study, beginning 2 weeks prior to their surgical date. The first dose will be consumed 60 minutes prior to any at- home or outpatient physical therapy session and a second will be consumed immediately following the session. If a treatment day does not include any rehabilitation session, the participant will consume one dose in the morning prior to food consumption and the second dose approximately 90 minutes later.
Dietary supplement: CaLa
Comparative placebo
Other Names:
  • Calcium Lactate

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
Change in leg lean muscle mass
Time Frame: every 6 weeks for 9-months
absolute leg lean mass (kg) change from baseline
every 6 weeks for 9-months
Change in leg lean muscle mass
Time Frame: every 6 weeks for 9-months
absolute muscle cross-sectional area (cm^2)
every 6 weeks for 9-months
Muscle Mass
Time Frame: every 6 weeks for 9-months
percent change cross-sectional area (%)
every 6 weeks for 9-months

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
Isometric leg strength change
Time Frame: every 3 months for 9-months
change in strength from baseline relative to contralateral limb (kg)
every 3 months for 9-months
Change in EMG amplitude
Time Frame: every 3 months for 9-months
absolute (RMS) change from baseline
every 3 months for 9-months

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
ALM body composition change
Time Frame: every 6 weeks for 9-months
appendicular lean mass (kg) change from baseline
every 6 weeks for 9-months
Fat mass body composition change
Time Frame: every 6 weeks for 9-months
fat mass (kg) change from baseline
every 6 weeks for 9-months
TBLM body composition change
Time Frame: every 6 weeks for 9-months
total body lean mass (kg) change from baseline
every 6 weeks for 9-months
Functional performance Asymmetry Index
Time Frame: measured at 14 and 26 weeks

symmetry difference between limbs, expressed as a percent Drop landing knee excursion (force, impulse) Vertical jump (height, force, impulse) Cross-over hop (distance) Single-leg hop (distance) Triple hop (distance) Figure-8 hop (time-sec.) Number of leg press repetitions

All scores aggregate to a single percent score comparing operative limb to non-operative limb.
measured at 14 and 26 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.
University of Kansas Medical Center

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Metabolic Technologies Inc.
National Strength and Conditioning Association

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.
May 29, 2023

Primary Completion (Estimated)

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.
December 1, 2028

Study Completion (Estimated)

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.
December 1, 2029

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).
March 14, 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.
May 18, 2023

First Posted (Actual)

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.
May 22, 2023

Study Record Updates

Last Update Posted (Actual)

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.
March 2, 2026

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.
February 26, 2026

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.
February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

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.
  • STUDY00149057

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

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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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