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 2018

Document Type


Degree Name

Master of Science (MS)


Department of Kinesiology


Nicholas D. Luden

Michael J. Saunders

Christopher J. Womack


Introduction: MicroRNA (miRNA) are small, non-coding RNA that act post-transcriptionally to regulate gene expression. miRNA levels are modulated by acute aerobic exercise, yet little is known about how miRNA levels may change in response to high-intensity interval exercise. Further, almost nothing is known about the impact of post-exercise nutrition (carbohydrate and/or protein) on miRNA levels. Thus, the purpose of this study is to examine the effects of high-intensity interval cycling and different post-exercise nutrients on ci-miRNA levels. Methods: Nine recreationally active males (age 21.9 ± 2.0yrs; VO2max 49.6 ± 4.0mL/kg/min) competed three trials, each including identical exercise protocols. Protocol involved two Wingate tests separated by four sets of high-intensity (3 minutes @ 90% Wmax separated by 1 minute @ 50% Wmax) intervals, along with warm-up and cooldown. Finger stick and venous blood samples were collected pre- and up to four hours post-exercise. Additionally, a different nutrition treatment (i.e. carbohydrate, carbohydrate + protein, or control) was administered immediately post-exercise. Serum samples were analyzed for content of twelve target miRNA (miR-1, -21, -126, -133a, -146a, -150, -206, -210, -221, -222, -486, and -499). miRNA levels were expressed as fold changes relative to baseline of 1 and paired-samples t-tests and post hoc two-way, repeated measures ANOVAs were used to detect changes in miRNA levels across chosen timepoints and treatments. Results: miR-210 and miR-486 were unaffected by exercise at any timepoints and all remaining targets were either unchanged or upregulated immediately post-exercise. Most targets (except miR-1) were returned to baseline at four-hours post-exercise. Nutrition only affected miR-150, downregulating it at one-hour post-exercise. Post hoc analysis revealed a main effect for time for all targets immediately post-exercise. Further, a main effect for time was observed one-hour post-exercise for miR-1 and miR-210 and at four hours pos-exercise for miR-210 and mIR-146a. Conclusion: High-intensity cycling impacted miRNA implicated in skeletal and cardiac phenotype, angiogenesis, and inflammation, though post-exercise nutrition was inconsequential except for miR-150. It is currently unknown the extent to which intracellular miRNA activity may be reflected in circulation, thus further work is needed to study how nutrition may influence miRNA response to exercise.