Handzlik & Gleeson 2013 ISRN Nutrition.pdf (1.48 MB)
Download fileLikely additive ergogenic effects of combined pre-exercise dietary nitrate and caffeine ingestion in trained cyclists.
journal contribution
posted on 2014-01-07, 15:36 authored by Michal K. Handzlik, Michael GleesonAims. To evaluate the possible additive effects of beetroot juice plus caffeine on exercise performance. Methods. In a randomized,
double-blinded study design, fourteen healthy well-trained men aged 22 ยฑ 3 years performed four trials on different occasions
following preexercise ingestion of placebo (PLA), PLA plus 5mg/kg caffeine (PLA+C), beetroot juice providing 8mmol of nitrate
(BR), and beetroot juice plus caffeine (BR+C). Participants cycled at 60% maximal oxygen uptake (VO2max) for 30min followed
by a time to exhaustion (TTE) trial at 80% VO2max. Saliva was collected before supplement ingestion, before exercise, and after
the TTE trial for salivary nitrate, nitrite, and cortisol analysis. Results. In beetroot trials, saliva nitrate and nitrite increased >10-fold
before exercise compared with preingestion (๐ โค 0.002). TTE in BR+C was 46% higher than in PLA (๐ = 0.096) and 18% and 27%
nonsignificant TTE improvements were observed on BR+C compared with BR and PLA+C alone, respectively. Lower ratings of
perceived exertion during TTE were found during 80% VO2max on BR+C compared with PLA and PLA+C (๐ < 0.05 for both).
Conclusions. Acute preexercise beetroot juice coingestion with caffeine likely has additive effects on exercise performance compared
with either beetroot or caffeine alone.
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