Bioenergetics of Exercise-Induced Menstrual Disturbances

Summary

Menstrual disturbances are frequently observed in physically active women and female athletes. Short term prospective studies have shown that diet and exercise interventions can lead to decreases in Luteinizing hormone (LH) pulsatility, however these studies are unable to capture further changes in menstrual status. One longer term prospective study over two menstrual cycles showed that weight loss elicited menstrual disturbances, but there were no quantifiable measurements of energy availability. Thus, the primary purpose of this study was to assess how varying levels of energy deficiency created through a combination of caloric restriction and exercise affect menstrual function in young, premenopausal, sedentary women.

Conditions

• Menstruation Disturbances
• Luteal Phase Defect
• Amenorrhea
• Oligomenorrhea

Interventions

OTHER

Sedentary Control

Diet: Participants consumed meals in the General Clinical Research Center metabolic kitchen that had calories sufficient to maintain body weight. Diet composition was 55 percent carbohydrates, 30 percent fat, and 15 percent protein.

OTHER

Exercising control

Exercise: Participants engaged in supervised exercise training in Noll Laboratory Diet: Participants consumed meals in the General Clinical Research Center metabolic kitchen that had calories sufficient to maintain body weight and additional calories to remain in energy balance. Diet composition was 55 percent carbohydrates, 30 percent fat, and 15 percent protein.

OTHER

15 percent energy deficit

Exercise: Participants engaged in supervised exercise training in Noll Laboratory that was equal to 15 percent of the participants' daily caloric needs. Diet: Participants consumed meals in the General Clinical Research Center metabolic kitchen that had calories to meet metabolic needs (before 15 percent deficit exercise). Diet composition was 55 percent carbohydrates, 30 percent fat, and 15 percent protein.

OTHER

30 percent energy deficit

Exercise: Participants engaged in supervised exercise training in Noll Laboratory that was equal to 30 percent of the participants' daily caloric needs. Diet: Participants consumed meals in the General Clinical Research Center metabolic kitchen that had calories to meet metabolic needs (before 30 percent deficit exercise). Diet composition was 55 percent carbohydrates, 30 percent fat, and 15 percent protein.

OTHER

30 percent energy deficit (15/15)

Exercise: Participants engaged in supervised exercise training in Noll Laboratory that was equal to 15 percent of the participants' daily caloric needs. Diet: Participants consumed meals in the General Clinical Research Center metabolic kitchen that had 15 percent less calories than those needed to meet metabolic needs. Diet composition was 55 percent carbohydrates, 30 percent fat, and 15 percent protein.

OTHER

60 percent energy deficit

Exercise: Participants engaged in supervised exercise training in Noll Laboratory that was equal to 30 percent of the participants' daily caloric needs. Diet: Participants consumed meals in the General Clinical Research Center metabolic kitchen that had 30 percent less calories than those needed to meet metabolic needs. Diet composition was 55 percent carbohydrates, 30 percent fat, and 15 percent protein.

Sponsors & Collaborators

• National Institutes of Health (NIH)

  collaborator NIH

• Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)

  collaborator NIH

• Penn State University

  lead OTHER

Principal Investigators

• Nancy I Williams, ScD · Penn State University

Study Design

Allocation

RANDOMIZED

Purpose

OTHER

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

30 Years

Sex

FEMALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2001-05-01

Primary Completion

2005-04-30

Completion

2005-04-30