Preferred Name

Paul Roberson

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.


Date of Graduation

Summer 2016

Document Type


Degree Name

Master of Science (MS)


Department of Kinesiology


Christopher J. Womack

Nicholas D. Luden

Michael J. Saunders


Introduction: Research has shown exercise elicits a hemostatic response affecting coagulation and fibrinolysis. Furthermore, prior research has determined circadian fluctuations exist where clotting potential increases in the morning as a result of increased PAI-1 and decreased tPA which is further exacerbated by exercise. These circadian fluctuations and exercise responses have the potential to be accentuated by poor sleep. The purpose of this study is to determine the effects of sleep restriction on tPA activity, PAI-1 activity, and Factor VIII antigen activity (FVIII) while resting and after exercise.

Methods: 7 Subjects underwent two similar exercises sessions (EX). EX1 occurred in the evening and involved a resting blood draw, peak leg extension torque, 20 min warm-up (10 min-50% Wmax; 10 min-60% Wmax), post-exercise blood draw, 3-km time trial, 60 min of intervals (2 min-50% Wmax; 2 min-95% Wmax), and 3x10 leg press (80% 1RM). The following morning, EX2 mimicked EX1 except no intervals or leg press were performed. Sleep prescription was assigned between EX1 and EX2. Subjects received both full and disturbed sleep.

Results: Two-way ANOVA found no significant main effect for sleep or any interactions between sleep and any of the other factors. There was a main effect for exercise for all variables, as well as for time of day for tPA and FVIII. Interactions for exercise and time of day were significant for tPA (Evening [pre-exercise = 0.32±0.14, post-exercise = 1.89±0.60 AU/mL] vs. Morning [pre-exercise = 0.27±0.13, post-exercise = 0.69±0.18 AU/mL]). and PAI-1 (Evening [pre-exercise = 0.78±0.26, post-exercise = 0.69±0.29 AU/mL] vs. Morning [pre-exercise = 7.06±2.66, post-exercise = 5.40±2.31 AU/mL]).

Conclusion: Sleep restriction does not appear to play a role in hemostasis. Diurnal rhythms increase coagulation potential in the morning shown by increases in PAI-1 and FVIII and decreases in tPA while resting and after exercise.



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