Award Date


Degree Type


Degree Name

Master of Science (MS)


Kinesiology and Nutrition Sciences

First Committee Member

James Navalta

Second Committee Member

Gabriele Wulf

Third Committee Member

Will Jonen

Fourth Committee Member

Szu-Ping Lee

Number of Pages



Introduction: The purpose of the present study was to examine whether implementing factors of OPTIMAL Theory: Enhanced Expectancies (EE), Autonomy Support (AS), and External Focus (EF) during a cycle exercise bout at a simulated altitude of 21,000 feet elevation had an effect on exercise performance and EPOC response in comparison to a control condition.

Methods: Sixteen participants (n = 8 women, n = 8 men) completed resting oxygen measurements (resting metabolic rate) between 6:00 A.M. and 8:00 A.M. Cycle exercise to fatigue at a constant workload was performed (100 W) while breathing air with reduced oxygen content to simulate exercising at altitude (9.4% fraction of oxygen, equivalent of 6401 m above sea level). All participants performed under two conditions, an optimized and a control condition. The order of conditions were counterbalanced. Following cycle to fatigue protocol, participants were reconnected to the metabolic analysis system and instructed to sit quietly until they returned to their baseline oxygen values (EPOC duration). EPOC magnitude was determined by adding up the net oxygen consumption for every minute during the EPOC duration. Data analysis consisted of paired t-tests.

Results: In summary, the results of this study reveal that cycle exercise performance between both conditions was significant, p = .03. Performance outcome measures included duration of cycle exercise to fatigue and mean watts (W). Participants were able to cycle longer in the optimized condition relative to the control, with exercise carried out at the same absolute workload. EPOC duration and magnitude in participants (N = 16) who performed cycling exercise at 100 W under simulated altitude of 6401 m (21,001 ft) to fatigue, resulted in no statistically significant difference between the following optimized and control conditions. Therefore, despite longer cycle exercise duration in the optimized condition, EPOC duration and magnitude in both conditions was not significantly different.

Discussion: The present findings adds to evidence that key variables in the OPTIMAL theory influence energy expenditure, enhance movement efficiency, and reduce oxygen consumption. To the best of our knowledge, this is the first study to investigate aerobic exercise performance and EPOC response where all three variables in OPTIMAL theory are applied consecutively during exercise. Thus, further investigation is necessary to examine the physiological parameters of other exercise intensities to asses if similar results are produced.


Exercise performance; Motivation; OPTIMAL Theory; Oxygen consumption; Simulated altitude



File Format


Degree Grantor

University of Nevada, Las Vegas




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