Award Date

5-15-2026

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Interdisciplinary Programs

First Committee Member

Szu-Ping Lee

Second Committee Member

Kevin Miller

Third Committee Member

Robert Gregor

Fourth Committee Member

Jennifer Pharr

Number of Pages

100

Abstract

Exercise-associated muscle cramps (EAMCs) are painful phenomenon that involves involuntary muscle spasms occurring during physical activity or directly after. 1 The landscape of the research on EAMC etiology has expanded from focusing on a single prevailing cause (e.g., hydration status) to a more holistic approach of how numerous factors contribute to the onset of neuromuscular fatigue, and the significance of each factor in those who suffer from EAMC. Following the multifactorial theory of cramp pathophysiology, this research sought to advance the knowledge of cramp susceptibility by investigating if there is a relationship between common psychophysiological factors like high anxiety, sleep loss, to the risk of EAMCs.

EAMCs are often studied systematically by inducing muscle cramps via electrical stimulation protocols in controlled environments. Using electrical stimulation, a cramp susceptibility indicator has been validated – known as the cramp threshold frequency (CTF) – and is defined as the minimum electrical stimulation frequency necessary to induce a muscle cramp.2 Cramp-prone individuals have a lower CTF than non-crampers, thus a lower CTF is linked to an increased risk of sustaining a cramp.3

The overall purpose of this dissertation was to determine if selected psychophysiological factors are related to a greater susceptibility of EAMCs among crampprone individuals. By using the CTF as a quantifiable measure of cramp risk, two studies were designed: 1) to explore the relationship between anxiety subscale levels and cramp susceptibility; 2) to identify associations between sleep duration and quality to cramp susceptibility.

In the first study, we investigated anxiety subscales like state versus trait anxiety levels, and cognitive versus somatic anxiety levels, and compared this to the CTF of crampprone individuals. When introduced to a stressor, those with higher levels of trait anxiety have been demonstrated to have higher somatic stress responses like increased muscle tension.4 Twenty participants with a history of cramping volunteered for this study, completed an electrical stimulation protocol to each obtain their CTF threshold value, and reported anxiety levels via the State-Trait Inventory for Cognitive and Somatic Anxiety (STICSA). 5 The results of this study suggested no significant association between anxiety measures on the STICSA and the CTF values in cramp-prone participants.

In the second study, we examined the relationships between sleep parameters like duration and quality, and CTF. Twenty cramp-prone participants volunteered for this study. After completing an electrical stimulation protocol to obtain their CTF, sleep parameters were assessed by three modes: the Pittsburgh Sleep Quality Index (PSQI), the Consensus Sleep Diary (CSD), and week-long use of an activity tracker to objectively monitor their sleep (Actigraph wGT3X-BT). The results of this study suggested that there were no significant relationships between sleep parameters and cramp risk in cramp-prone participants.

Ultimately while this series of cross-sectional studies did not uncover a significant relationship between chronic sleep habits or higher anxiety in known crampers at present, it may serve as a springboard into greater discussion on potentially related risk factors that can be controlled or manipulated to reduce the risk of EAMC. This project also established the study design and methodology that can be used in future studies of how psychophysiological factors impact the risk of EAMC. Further research should still seek to identify if anxiety and disordered sleep could acutely affect cramp risk in a pre- to post-test study design in individuals who frequently experience acute anxiety bouts or sleep disruption, such as in competitive athletes. Additionally, EAMC researchers should explore the significance of other known risk factors in cramp susceptibility, to identify targets for prevention and treatment strategies.

Keywords

anxiety; cramp threshold frequency; CTF; EAMC; exercise associated muscle cramps; sleep

Disciplines

Medical Specialties | Medicine and Health Sciences | Sports Medicine

File Format

PDF

File Size

1943 KB

Degree Grantor

University of Nevada, Las Vegas

Language

English

Rights

IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/

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