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Red Spinach Extract Increases Ventilatory Threshold during Graded Exercise Testing
- Source :
- Sports, Vol 5, Iss 4, p 80 (2017)
- Publication Year :
- 2017
- Publisher :
- MDPI AG, 2017.
-
Abstract
- Background: We examined the acute effect of a red spinach extract (RSE) (1000 mg dose; ~90 mg nitrate (NO 3 − )) on performance markers during graded exercise testing (GXT). Methods: For this randomized, double-blind, placebo (PBO)-controlled, crossover study, 15 recreationally-active participants (aged 23.1 ± 3.3 years; BMI: 27.2 ± 3.7 kg/m2) reported >2 h post-prandial and performed GXT 65–75 min post-RSE or PBO ingestion. Blood samples were collected at baseline (BL), pre-GXT (65–75 min post-ingestion; PRE), and immediately post-GXT (POST). GXT commenced with continuous analysis of expired gases. Results: Plasma concentrations of NO 3 − increased PRE (+447 ± 294%; p < 0.001) and POST (+378 ± 179%; p < 0.001) GXT with RSE, but not with PBO (+3 ± 26%, −8 ± 24%, respectively; p > 0.05). No effect on circulating nitrite (NO 2 − ) was observed with RSE (+3.3 ± 7.5%, +7.7 ± 11.8% PRE and POST, respectively; p > 0.05) or PBO (−0.5 ± 7.9%, −0.2 ± 8.1% PRE and POST, respectively; p > 0.05). When compared to PBO, there was a moderate effect of RSE on plasma NO 2 − at PRE (g = 0.50 [−0.26, 1.24] and POST g = 0.71 [−0.05, 1.48]). During GXT, VO2 at the ventilatory threshold was significantly higher with RSE compared to PBO (+6.1 ± 7.3%; p < 0.05), though time-to-exhaustion (−4.0 ± 7.7%; p > 0.05) and maximal aerobic power (i.e., VO2 peak; −0.8 ± 5.6%; p > 0.05) were non-significantly lower with RSE. Conclusions: RSE as a nutritional supplement may elicit an ergogenic response by delaying the ventilatory threshold.
Details
- Language :
- English
- ISSN :
- 20754663
- Volume :
- 5
- Issue :
- 4
- Database :
- Directory of Open Access Journals
- Journal :
- Sports
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.5b35db5154c9409ab55672af09976b13
- Document Type :
- article
- Full Text :
- https://doi.org/10.3390/sports5040080