THE IMPACTS OF ALTERED METABOLISM AND PSYCHOLOGICAL STRESS IN EXERCISING WOMEN
Open Access
- Author:
- Strock, Nicole Christine
- Graduate Program:
- Kinesiology
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- February 24, 2021
- Committee Members:
- Mary Jane De Souza, Dissertation Advisor/Co-Advisor
Mary Jane De Souza, Committee Chair/Co-Chair
Nancy Williams, Committee Member
David Nathan Proctor, Committee Member
Lorah D Dorn, Outside Member
Rebecca Jane Mallinson, Special Member
Nancy Williams, Program Head/Chair - Keywords:
- Female Athlete Triad
energy deficiency
metabolism
menstrual disturbances
amenorrhea
oligomenorrhea
resting metabolic rate
disordered eating
psychological stress
REFUEL
nutritional intervention - Abstract:
- The complex interrelation between menstrual dysfunction and bone health consequences stemming from a chronic energy deficit is called the Female Athlete Triad (Triad), impacting up to 60% of exercising women. The high prevalence and lasting physiological consequences of the Triad in women urges the utilization of objective and reliable methods of energy assessment for early identification of Triad-risk factors. Additionally, understanding the time course and magnitude of recovery for those who already present with Triad symptomatology is vital. Therefore, the overall purpose of this dissertation is to inform and improve our ability for early detection, prevention, and treatment of metabolic and reproductive consequences which stem from chronic energy deficiency. Specifically, I aimed to: i) evaluate measured-to-predicted resting metabolic rate (RMR) ratio as it relates to known physiological consequences of energy deficiency, and confirm the use of the threshold cutoff values to estimate energy deficiency (Study 1), ii) examine the relationship between RMR ratio and total triiodothyronine (TT3) in exercising, ovulatory, weight-stable women over a 12-month observational period (Study 2) and in exercising women with menstrual disturbances during a 12-month dietary intervention (Study 4), and iii) explore whether psychological factors, in addition to metabolic factors, also contribute to amenorrhea in exercising women (Study 3) and whether these psychological factors are altered with 12-month dietary intervention (Study 5). Key findings of this dissertation include: i) the RMR ratio is an objective and accurate measure to determine energetic status as indicated by TT3 in exercising women and different prediction methods require a specific threshold, ii) the RMR ratio has excellent reliability for repeated measures during a 12-month observation period in weight-stable women and is predictive of TT3 in exercising women with changing energetic status, iii) a 12-month nutritional intervention in exercising women with menstrual disturbances improves body composition with a delayed improvement in TT3, iv) energy deficient exercising women with menstrual disturbances exhibit disordered eating behaviors which may be related to underlying depressive characteristics, and v) a 12-month nutritional intervention in exercising women with menstrual disturbances does not worsen disordered eating behaviors, stress, or depression. Together, these studies contribute valuable information to improve our ability to identify Triad-associated health consequences and supports long-term nutritional therapy is a successful approach to remedying the energy deficiency underlying the Triad without causing unintended decrements to the psychological profile of these exercising women.