Effect of Intense Training on Ovarian Function and Bone Turnover

January 26, 2016 updated by: USDA, Western Human Nutrition Research Center

Impact of Intense Exercise Training on Energy Availability, Ovarian Function and Bone Turnover in Female Athletes

The investigators propose a prospective, longitudinal, department funded study protocol to evaluate whether changes in energy availability, during a period of highly intensified exercise training, will increase bone turnover markers and decrease ovarian function and exercise performance, in a dose-dependent fashion in competitive female athletes.

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

Female athletes participating in sports which emphasize leanness as a factor to success, while also imposing large exercise training loads, present a high prevalence of endocrine and metabolic alterations linked to low energy stores, including suppressed ovarian function and bone loss. Increased bone turnover resulting from low energy stores and suppressed estrogen production may hold the most adverse consequences for long term health, increasing the risk of premature osteopenia, while increasing the risk of stress fractures in the short term. Chronically low energy stores may also contribute to the development of overreaching and overtraining syndromes, characterized by excessive, lasting fatigue and long-term decreases in performance, which can compromise these athletes' health and athletic career. The investigators propose the first longitudinal study aiming to demonstrate the link between low energy status, impaired ovarian function, bone turnover and decreased performance in free-living, competitive female athletes. After a 4-week baseline period of habitual training, athletes will undergo 4 weeks of intensified training (IT), during which the exercise load is increased by 30% from their individual baseline load in order to sharply increase energy expenditure. As athletes will be let to freely adjust their food intake, the investigators aim to test the hypothesis that athletes will fail to adjust food intake sufficiently to match energy expenditure, and that the resulting decrease in energy availability (EA, energy intake - energy expenditure from exercise) will influence, in a dose-dependent fashion, the suppression of estrogen production, the increase in bone turnover and the severity of performance decrement. The IT period will then be followed by a 2-week taper (REC), in which exercise training volume will be reduced by 50% from baseline. The investigators will assess whether EA returns to baseline values, and characterize changes in bone turnover during this recovery period. It is hypothesized that any improvements in exercise performance resulting from IT + REC will occur in athletes who were able to remain closest to a balanced energy state during IT. Concretely linking EA to both performance and bone health may incentivize female athletes to adopt more adequate feeding behaviors for their activity level.

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.
18

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
    • California
      • Davis, California, United States, 95616
        • USDA Western Human Nutrition Research Center

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

18 years to 40 years (Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Female

Description

Inclusion Criteria:

  • competitive endurance runners (racing in events ranging from 10km to ultra-marathons)
  • training at least 5 days per week over the past 12 months, and more than 30 miles per week
  • regular menstrual cycles (24-35 days) over the past 6 months
  • maximal oxygen consumption (VO2max) > 50ml/kg/min
  • English speaking

Exclusion Criteria:

  • smoker
  • amenorrhea
  • pregnant or lactating in the past 2 years
  • chronic disease that will affect bone health, metabolism or the cardiorespiratory system
  • take medications that have cardiovascular or metabolic effects
  • present any contra-indication to exercise testing (cardiovascular abnormalities)
  • report any major illness or injury preventing training for more than 4 weeks over the past 3 months
  • a history of clinical anorexia nervosa or bulimia nervosa

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: Basic Science
  • Allocation: N/A
  • Interventional Model: Single Group 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: Intensified training
Volunteers will increase exercise training by 30% from baseline
Behavioral: Intensified Training
Volunteers will increase exercise training by 30% from baseline

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 energy availability (energy intake - energy expenditure of physical activity)
Time Frame: Baseline (week 4), after 4 weeks of intensified training (week 8) and after a two-week recovery period (week 10)
The investigators aim to capture the spectrum and variability of energy availability in endurance athletes under normal training conditions, describing in detail training regimen, total energy expenditure and nutrition habits during three distinct phases of training that are habitually followed by endurance athletes.
Baseline (week 4), after 4 weeks of intensified training (week 8) and after a two-week recovery period (week 10)

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
Change in athletic performance
Time Frame: Baseline (week 4), after 4 weeks of intensified training (week 8) and after a two-week recovery period (week 10)
The investigators will measure the effect of energy availability on exercise performance during baseline, after 4 weeks of intensified training, and after a 2-week recovery, by measuring the relationship of energy availability to maximal oxygen consumption (VO2max) and 3200 meter time trial performance. The investigators will test the hypothesis that performance will be affected by changes in energy availability in a dose-dependent fashion.
Baseline (week 4), after 4 weeks of intensified training (week 8) and after a two-week recovery period (week 10)
Change in ovarian function
Time Frame: Baseline (week 4), after 4 weeks of intensified training (week 8) and after a two-week recovery period (week 10)
The investigators will measure salivary estradiol and progesterone concentrations daily throughout the study, in order to test the hypothesis that ovarian function may be suppressed by intensified training and decreased energy availability.
Baseline (week 4), after 4 weeks of intensified training (week 8) and after a two-week recovery period (week 10)
Change in bone turnover markers
Time Frame: Baseline (week 4), after 4 weeks of intensified training (week 8) and after a two-week recovery period (week 10)
The investigators will measure plasma bone turnover markers during baseline and at the end of the intensified training period, in order to test the hypothesis that bone turnover may be compromised by intensified training and decreased energy availability.
Baseline (week 4), after 4 weeks of intensified training (week 8) and after a two-week recovery period (week 10)

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.
USDA, Western Human Nutrition Research 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.
University of California, Davis

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: Gretchen A Casazza, PhD, University of California, Davis

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

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

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.
January 1, 2014

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.
December 1, 2015

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.
December 1, 2015

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).
August 21, 2014

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.
August 22, 2014

First Posted (Estimate)

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.
August 25, 2014

Study Record Updates

Last Update Posted (Estimate)

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.
January 28, 2016

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.
January 26, 2016

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.
September 1, 2015

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.
  • FL94

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

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