Date of Award


Document Type

Open Access Thesis

Degree Name

Master of Science (MS)



First Advisor

Ryan Fiddler, Ph.D.

Second Advisor

John Foley, Ph.D.

Third Advisor

Peter M. McGinnis, Ph.D.


The desire for performance enhancement is a common goal amongst athletes. Recently a number of studies have reported various performance enhancing effects of dietary nitrate (NO3-) via beetroot juice (BRJ) supplementation. Research has indicated that the various performance enhancing effects of BRJ can be attributed to a decrease resting systolic blood pressure (SBP), diastolic blood pressure (DBP), and submaximal volume of oxygen consumption (VO2), while increasing vasodilation and mitochondrial efficiency. Purpose: The purpose of this study was to investigate whether BRJ supplementation improves swimming performance in collegiate level swimmers. Methods: Eight collegiate trained swimmers underwent a double-blind 5-day chronic supplementation of 140-mL-day-1 BRJ containing roughly 8.5-mmol of NO3- and placebo (PL). Participants performed three separate tests, baseline, BRJ, and PL. During the testing resting systolic (SBP) and diastolic blood pressure (DBP) was measures along with completion of a 500-yard freestyle time trials followed by a 100-yard freestyle time trial sprint. Supplementation periods were separated by an 8-day washout. One-way repeated measures ANOVA were used to determine the effect of treatment (BRJ or PL) on SBP, DBP, 500-yard freestyle and 100-yard freestyle time trials. Results: There were insignificant drops in 500-yard freestyle performance of 1.52% F(2, 14) = 3.19, p = .0722, 100-yard freestyle time trial sprint of .88% F(2, 14) = 1.48, p = .2608, and SBP of 1.92% F(2, 14) = 0.65, p = .5378, while a significant increase in DBP of 8.7% after BRJ supplementation F(2, 14) = 11.62, p = .0011. Conclusion: 5-day dietary NO3- rich BRJ supplementation had no significant effect on resting SBP, 500-yard freestyle time trial and 100-yard freestyle time trial sprint among collegiate trained swimmers. However, our participants saw similar percentage drops in 500-yard freestyle time trial and 100-yard freestyle time trial sprint to that of past research involving BRJ supplementation and swimming.