Senior Honors Projects, 2020-current
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Date of Graduation
5-13-2023
Semester of Graduation
Spring
Publish
yes
Degree Name
Bachelor of Science (BS)
Department
Department of Kinesiology
First Advisor
Trent Hargens
Second Advisor
Nicholas Luden
Third Advisor
Nicholas Luden
Abstract
Purpose: To examine the effect of sleep chronotype and sleep quality on one’s ability to perform a maximal treadmill test in the morning and evening.
Methods: 13 individuals [age = 20.08 ± 1.04 yr] completed three graded exercise tests (GXT) on a treadmill. The familiarization test was done first at any time of day. The experimental trials were labeled as the “morning GXT” and the “evening GXT”. Experimental tests, completed in random order, were performed 7-14 days following the familiarization test between 7:00 and 9:00 am for the morning GXT and between 6:00 and 8:00 pm for the evening GXT. In addition, physical activity and sleep quality were measured with an accelerometer for a full seven days. Sleep chronotype was determined with a Morningness-Eveningness Questionnaire.
Results: Ventilation/carbon dioxide production (VE/VCO2) slope showed a trend to be lower in the evening (24.8 ± 3.42) compared to the morning (26.1 ± 3.9) for all chronotypes (p=0.077). For the moderately morning types, sleepiness was significantly lower (p=0.04) in the morning (3.6 ± 1.14) versus the evening (5.8 ± 1.10), and ventilation max (VE max) was significantly higher (p=0.025) in the morning (90.2 ± 8.3) compared to the evening (85.3 ± 5.5). Additionally, VE/VCO2 slope showed a trend to be lower (p=0.081) in the evening (24.7 ± 4.6) than the morning (27.1 ± 5.0). For the neither chronotype, VO2max and METmax were significantly lower (p=0.048 and 0.049, respectively) in the morning (40.8 ± 6.6 and 11.7 ± 1.9, respectively) than the evening (44.3 ± 5.8 and 12.7 ± 1.7, respectively), but sleepiness was not significantly different (p=0.809).
Conclusion: VO2max was significantly lower during the morning GXT for those classified as the neither chronotype despite rating their sleepiness equal to the evening GXT. Reasons for this are unclear, so more research on intermediate chronotypes is needed to properly address this.
