Abstract : Beetroot juice (BRJ) contains a high concentration of
inorganic nitrates, previously shown to improve blood flow to skeletal
muscle. Recent studies in males have found that acute BRJ
supplementation can improve aerobic exercise performance. However,
the effects of BRJ supplementation on exercise performance in females
is currently unknown. Purpose: This study aimed to determine the
effect of BRJ supplementation on aerobic performance in females.
Methods: This study was a randomized placebo-controlled trial where
participants (n=18), healthy trained females (22.9 ± 5.6 years, 165.8 ±
7.14 cm, 64.0 ± 0.57 kg), were divided into threedifferent groups: the placebo
group (PLG; n=9), the BRJ group (n=9), and the BRJ concentrate group (50ml) (~8,2 mmol NO3−).
Three hours after taking the supplement, participants completed
cardiopulmonary exercise testing (CPET) on a cycle ergometer at a constant
work rate (W), using a gas exchange measurement, including the uptake of oxygen
(V̇O2) and exhaled carbon dioxide (V̇CO2), with traditional exercise testing
parameters. Results: Results of maximal oxygen consumption in the BRJ group
in the first test and in the second test after 50ml BRJ showed significant
(p<0.001) changes after the second test. Maximal oxygen consumption
(VO2max) increased by 4.82% (from 35.24±5.07 to 36.94±4.91) in contrast
with the PLG where results decreased by 0.57% between the first test and the
second test (from 35.06±4.87 to 34.86±5.01).
Respiratory efficiency (VE/VO2) increased by 0.84% in the PLG (from
34.53±2.67 to 34.79±3.38) and decreased by 4,25% in the BRJ group (from
35.01±2.38 to 33.52±2.10).
Conclusion: This data demonstrate that dietary supplementation
with NO3- can be considered an ergogenic aid and may have therapeutic effects
in hypoxic environments as well as improve cardiovascular health in female
athletes.