Details

Autor(en) / Beteiligte

• Shannon, Oliver Michael
• Barlow, Matthew John
• Duckworth, Lauren
• Williams, Emily
• Wort, Georgina
• Woods, David
• Siervo, Mario
• O’Hara, John Paul

Titel

Dietary nitrate supplementation enhances short but not longer duration running time-trial performance

Ist Teil von

• European journal of applied physiology, 2017-04, Vol.117 (4), p.775-785

Ort / Verlag

Berlin/Heidelberg: Springer Berlin Heidelberg

Erscheinungsjahr

2017

Link zum Volltext

Quelle

Springer journals

Beschreibungen/Notizen

• Purpose This study evaluated the effects of dietary nitrate (NO 3 − ) supplementation on physiological functioning and exercise performance in trained runners/triathletes conducting short and longer-distance treadmill running time-trials (TT). Method Eight trained male runners or triathletes completed four exercise performance tests comprising a 10 min warm up followed by either a 1500 or 10,000 m treadmill TT. Exercise performance tests were preceded 3 h before the exercise by supplementation with either 140 ml concentrated nitrate-rich (~12.5 mmol nitrate) (BRJ) or nitrate-deplete (~0.01 mmol nitrate) (PLA) beetroot juice. Results BRJ supplementation significantly elevated plasma [NO 2 − ] ( P  < 0.05). Resting blood pressure and exercise  V ˙ O 2 were not significantly different between BRJ and PLA ( P  > 0.05). However, post-exercise blood [lactate] was significantly greater in BRJ following the 1500 m TT (6.6 ± 1.2 vs. 6.1 ± 1.5 mM; P  < 0.05), but not significantly different between conditions in the 10,000 m TT ( P  > 0.05). Performance in the 1500 m TT was significantly faster in BRJ vs. PLA (319.6 ± 36.2 vs. 325.7 ± 38.8 s; P  < 0.05). Conversely, there was no significant difference in 10,000 m TT performance between conditions (2643.1 ± 324. 1 vs. 2649.9 ± 319.8 s, P  > 0.05). Conclusion Acute BRJ supplementation significantly enhanced 1500 m, but not 10,000 m TT performance. These findings suggest that BRJ might be ergogenic during shorter distance TTs which allow for a high work rate, but not during longer distance TTs, completed at a lower work rate.