Exercise Mode and Acute Bone Resorption

July 18, 2025 updated by: VA Office of Research and Development

Comparison of Exercise Mode on Disruptions in Calcium Homeostasis

Endurance exercise is often recommended to improve cardiometabolic health and maintain bone health throughout life and to prevent osteoporotic fracture. However, there is evidence to suggest that bone does not always adapt in the way that is expected, and that endurance exercise may lead to bone loss under certain conditions. Disruptions in calcium homeostasis during exercise may explain this observation, and preliminary data suggests that the mode of exercise (i.e., cycling versus treadmill) may result in different magnitudes of change in bone biomarkers. The purpose of this study is to determine if mode of exercise results in a differential bone biomarker response to an acute exercise bout in older Veterans. Blood samples will be collected before, during, and after 2 acute exercise bouts: 1) brisk treadmill walking; and 2) vigorous stationary cycling. Bouts will be matched for relative intensity and duration. This data will be used to develop future exercise interventions in older Veterans aimed at preserving both cardiometabolic and bone health.

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

Endurance exercise is frequently recommended as a means to reduce the risk of cardiometabolic diseases and to reduce the risk of osteoporotic fracture. However, bone does not always adapt in the way that would be expected, and there is evidence that endurance exercise may lead to bone loss under certain conditions. It is the investigators contention that disruptions in calcium homeostasis during exercise, resulting in decreases in serum ionized calcium (iCa) and increases in parathyroid hormone (PTH) and c-telopeptide of type I collagen (CTX; a marker of bone resorption) at the onset of exercise, may be responsible for the lack of improvements in bone mineral density that are anticipated. Acute studies in this area have predominantly focused on young, healthy adults, primarily men, during stationary cycling exercise. Few studies have been conducted in older adults, but those studies have found that older adults experience similar disruptions in calcium homeostasis in response to an acute bout of endurance exercise. Preliminary comparisons of the investigators studies, as well as research from other labs, also suggests that that mode of exercise conducted during these acute exercise bouts may be an important determining factor in the catabolic bone response to exercise. It appears that weight-bearing exercise (i.e., treadmill) results in smaller increases in PTH and CTX compared to weight-supported exercise (i.e., stationary cycling). This has never been tested using a within-subjects design, so it is unclear if these observed differences are due to the mode of exercise, lab-to-lab differences, or other underlying factors. To address this gap in knowledge, 30 Veterans (15 men, 15 women), aged 60+ years, will complete two 1-hour acute exercise bouts: 1) brisk treadmill walking at 70-80% of maximal heart rate; 2) vigorous stationary cycling at 70-80% maximal heart rate. Blood samples will be collected to measure iCa, PTH, CTX and procollagen type I n-terminal propeptide (P1NP) before, during, and after each exercise bout. The order of the exercise bouts will be randomized and counter-balanced. The primary aim is to determine if mode of exercise results in a differential bone biomarker response in older Veterans. This information is essential for understanding how future exercise interventions should be designed to benefit both cardiometabolic health and bone health. This is especially relevant to Veteran health due to the high burden of both cardiometabolic diseases (e.g., diabetes, heart disease) in the population, as well as evidence of increased osteoporotic fracture risk. The proposed research is significant because it is addressing a knowledge gap that has prevented the ability to design exercise and lifestyle interventions aimed at preserving multiple components of Veteran health, which could have a lasting impact on Veteran quality of life and functional independence. The proposed research is innovative because it is testing a novel hypothesis, the mode of exercise on disruptions in calcium homeostasis, in a population that could greatly benefit from the knowledge to be gained. While the proposed research is an acute study, the results generated will be used to design future clinical interventions for Veteran health. Long-term, information gained from this research will help to define the optimal exercise prescription to improve cardiometabolic without compromising bone health aging Veterans.

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.
9

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 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.

Study Contact Backup

Study Locations

  • United States
    • Colorado
      • Aurora, Colorado, United States, 80045-7211
        • Rocky Mountain Regional VA Medical Center, Aurora, CO

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

60 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Healthy older (60+ y) Veteran women and men will be eligible to participate
  • All volunteers must be accustomed to performing 60 minutes of vigorous cycling and treadmill exercise

Exclusion Criteria:

  • impaired renal function, defined as an eGRF of <60 mL/min/1.73m2;(Florkowski and Chew-Harris 2011)
  • hepatobiliary disease, defined as liver function tests (AST, ALT) >1.5 times the upper limit of normal
  • thyroid dysfunction, defined as an ultrasensitive thyroid stimulating hormone (TSH) <0.5 or >5.0 mU/L
  • serum Ca <8.5 or >10.3 mg/dL; 5) serum 25(OH)D <20 ng/mL
  • uncontrolled hypertension, defined as resting systolic blood pressure (BP) >150 mmHg or diastolic BP >90 mmHg
  • history of type 1 or type 2 diabetes

  • cardiovascular disease; defined as subjective or objective indicators of ischemic heart disease (e.g., angina, ST segment depression) or serious arrhythmias at rest or during the graded exercise test (GXT)

    • volunteers who have a positive GXT can be re-considered after follow-up evaluation, which must include diagnostic testing (e.g., stress echocardiogram or thallium stress test) with interpretation by a cardiologist
  • anemia, defined as a serum hemoglobin <12.1 g/dL for women and <14.3 g/dL for men
  • fracture in the past 6 months

  • current diagnosis or symptoms of COVID-19

    • In the event of abnormal BP, live function, TSH, 25(OH)D, or hemoglobin values, volunteers can be reassessed, including after appropriate follow-up evaluation and treatment by a primary care provider
    • Those who have experienced symptoms of COVID-19 or have been formally diagnosed will be allowed to participate once symptoms have resolved and they are approved to return to exercise by their primary care provider

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: Prevention
  • 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.
Experimental: Stationary Cycling
All participants will complete one, 60-minute bout of stationary cycling
Behavioral: Exercise Mode
Stationary cycling or treadmill walking
Experimental: Treadmill Walking
All participants will complete one, 60-minute bout of treadmill walking
Behavioral: Exercise Mode
Stationary cycling or treadmill walking

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
C-telopeptide of Type I Collagen (CTX) Change
Time Frame: Before to up to 48 hours after acute exercise bout
CTX is a blood marker of bone resorption. Reference range is 0.1-0.8 ng/mL with lower concentrations suggesting less bone resorption.
Before to up to 48 hours after acute exercise bout

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
Procollagen of Type I N-terminal Propeptide (P1NP) Change
Time Frame: Before to up to 48 hours after acute exercise bout
PINP is a blood marker of bone formation. Reference range is 19-80 ng/mL with lower concentrations suggesting less bone formation.
Before to up to 48 hours after acute exercise bout

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.
VA Office of Research and Development

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.
University of Colorado, Denver

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: Sarah J Wherry, PhD, Rocky Mountain Regional VA Medical Center, Aurora, CO

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.
October 8, 2021

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.
June 30, 2024

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.
September 30, 2024

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 22, 2021

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.
March 22, 2021

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.
March 25, 2021

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.
July 20, 2025

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.
July 18, 2025

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.
July 1, 2025

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.
  • F3593-P
  • 1I21RX003593 (U.S. NIH Grant/Contract)

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

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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