G. Greisman, J. Kloubec, K. Morrow, C. Harris, A. Kazaks

Bastyr University, Kenmore, WA

The nitrates found in beetroot juice (BR) are known to be a precursor of nitric oxide (NO). NO is a known vasodilator which allows more oxygen to travel in the blood and may improve muscle efficiency. PURPOSE: This study aims to set up a testing protocol to evaluate the effects of beetroot juice on anaerobic power and performance in trained CrossFit athletes. METHODS: The protocol was a randomized, cross-over, double-blind, placebo-controlled design to measure 500-meter row time, countermovement jump (CMJ), and blood lactate levels before and after the row. Participants consumed either 2.7 oz shot of BR (6.5 mmol nitrate) or a placebo nitrate-free beetroot juice (PL). Two hours later, they rowed 500 meters at maximum capacity. Measurements of blood lactate and the highest of 3 CMJs were recorded before and after the row. After a 7-day washout period, athletes repeated this sequence with either BR or PL for comparison. This study was performed in Fall 2019 at Mercer Island CrossFit with athletes who had at least six months CrossFit experience and were very familiar with the Concept 2 Rower. RESULTS: Twenty-five athletes over age 18 (18 females, age range 25 to 60, average age 44) participated. The range of 500-meter row time was 1:28.8 – 2:26.4 (1:50.9 median). Blood lactate ranged from 0.8 to 5.6 (1.6) mmol before the row and 5.0 to 21.2 (10.2) mmol post row. Net CMJ ranged from 7.5 to 23.9 (11.9) inches pre row to 7.6 to 19.8 (11.4) inches post row. The median of the CMJ remained fairly stable pre and post row as not all athletes experienced muscle fatigue after the row. CONCLUSION: There were some inconsistencies in the measurement of the CMJ as athletes used chalk on their fingers to mark the spot on the wall next to a ruler. Most athletes tolerated the BR, though some had GI distress and others did not like the taste. All athletes were enthusiastic about participating and all but two participants agreed to measure their blood lactate. Overall, this protocol for measuring anaerobic power and performance was successful, though modifying the CMJ procedure could eliminate some inconsistencies.

Supported by Bastyr student research funding.

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