Effects of Beetroot Juice on Recovery and Performance Between Bouts of Repeated Sprint Exercise

Abstract Background: The effects of pyruvate on metabolic acidosis and oxidative metabolism had been studied. The ability to attenuate acidosis and improve oxidative system contribution are critical to the performance of team sport athletes during perform multiple high-intensity exercise over a limited period of time. This study aimed to investigate the impact of pyruvate supplementation on energy metabolism and metabolic acidosis during high-intensity interval exercise (HIIE), as well as to evaluate its role on repeated sprint exercise (RSE) performance.Methods: 14 well-trained male college soccer athletes (age: 20 ± 2 years, body fat: 13.11 ± 3.50 %) were studied in a randomized, double-blind, cross-over study. The participants ingested either 0.1g/kg/d of pyruvate or a placebo for 1-week. Metabolic acidosis was induced by HIIE after the supplement period, and RSE ability in the acidosis state was assessed. Venous blood pH, bicarbonate (HCO3-) and base excess (BE) were measured at baseline, pre-HIIE, post-HIIE, pre-RSE and post-RSE. Finger-stick blood lactate were collected at baseline, immediately after each bout of HIIE and 3, 5, 7, 10 min after HIIE. The energy systems contribution during HIIE were estimated. Results: Blood pH, HCO3- and BE were significantly lower than baseline after HIIE (p < 0.01) in both pyruvate group (PYR) and placebo group (PLA). Compared to PLA, the blood pH, HCO3- and BE were significantly improved in PYR at pre-HIIE (p < 0.01), post-HIIE (p < 0.01) and pre-RSE (p < 0.01). Furthermore, blood BE remained higher in PYR than PLA till end of RSE (p < 0.05). The contribution of oxidative system in the fourth bout of HIIE was higher in PYR than PLA (p < 0.05). In PLA, the ratio of total anaerobic energy contribution during HIIE was higher than that of aerobic (oxidative) (p < 0.01), but not in PYR (p > 0.05). Relative peak power (RPP) of first, fifth sprint, relative average power (RAP) of fifth sprint, the average of RPP and RAP during RSE were significantly improved in PYR compared with PLA (p < 0.05). While no significant changes in the PD% of each bout (p > 0.05) or average PD% (p > 0.05) were observed between the two groups. Conclusion: Pyruvate supplementation for 1-week enhances oxidative system energy contribution and buffers metabolic acidosis during HIIE, and improves RSE performance in acidosis.

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The Effect of Dietary Nitrate Supplementation on Physiology and Performance in Trained Cyclists

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2016-0202 ◽

2017 ◽

Vol 12 (5) ◽

pp. 684-689 ◽

Cited By ~ 9

Author(s):

Joseph A. McQuillan ◽

Deborah K. Dulson ◽

Paul B. Laursen ◽

Andrew E. Kilding

Keyword(s):

Time Trial ◽

Crossover Design ◽

Moderate Intensity ◽

Beetroot Juice ◽

Double Blind ◽

Dietary Nitrate ◽

Performance Time ◽

Exercise Economy ◽

Nitrate Supplementation ◽

And Performance

Purpose:To determine the effect of dietary nitrate (NO3 –) supplementation on physiology and performance in well-trained cyclists after 6–8 d of NO3 – supplementation.Methods:Eight competitive male cyclists (mean ± SD age 26 ± 8 y, body mass 76.7 ± 6.9 kg, VO2peak 63 ± 4 mL · kg–1 · min–1) participated in a double-blind, placebo-controlled, crossover-design study in which participants ingested 70 mL of beetroot juice containing ~4 mmol NO3 – (NIT) or a NO3 –-depleted placebo (PLA), each for 8 d. Replicating pretreatment measures, participants undertook an incremental ramp assessment to determine VO2peak and first (VT1) and second (VT2) ventilatory thresholds on d 6 (NIT6 and PLA6), moderate-intensity cycling economy on d 7 (NIT7 and PLA7), and a 4-km time trial (TT) on d 8 (NIT8 and PLA8).Results:Relative to PLA, 6 d of NIT supplementation produced unclear effects for VO2peak (mean ± 95% confidence limit: 1.8% ± 5.5%) and VT1 (3.7% ± 12.3%) and trivial effects for both VT2 (–1.0% ± 3.0%) and exercise economy on d 7 (–1.0% ± 1.6%). However, effects for TT performance time (–0.7% ± 0.9%) and power (2.4% ± 2.5%) on d 8 were likely beneficial.Conclusions:Despite mostly unclear outcomes for standard physiological determinants of performance, 8 d of NO3 – supplementation resulted in likely beneficial improvements to 4-km TT performance in well-trained male endurance cyclists.

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Development of a Soccer Simulation Protocol to Include Repeated Sprints and Agility

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.6.3.427 ◽

2011 ◽

Vol 6 (3) ◽

pp. 427-431 ◽

Cited By ~ 6

Author(s):

Keeron J. Stone ◽

Jonathan L. Oliver ◽

Michael G. Hughes ◽

Michael R. Stembridge ◽

Daniel J. Newcombe ◽

...

Keyword(s):

Match Play ◽

Heart Rates ◽

Repeated Sprints ◽

Soccer Match ◽

Repeated Sprint ◽

Movement Characteristics ◽

Simulation Protocol ◽

And Performance

Existing procedures for the simulation of soccer match play fail to incorporate multidirectional and repeated-sprint activities, even though these movements are considered fundamental to match play. In the current study, selected physiological and performance responses were assessed during an adapted version of an existing soccer simulation protocol. Mean heart rates of 163 ± 14 beats·min–1, mean blood lactates of 4.9 ± 2.3 mmol·L-1 and decrements in single-sprint and repeated-sprint performances were observed. The presented adaptations to an existing soccer simulation protocol better reflect the movement characteristics as well as the physiological and performance responses of soccer match play.

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Acute beetroot juice administration improves peak isometric force production in adolescent males

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2018-0050 ◽

2018 ◽

Vol 43 (8) ◽

pp. 816-821 ◽

Cited By ~ 7

Author(s):

David Bender ◽

Jeremy R. Townsend ◽

William C. Vantrease ◽

Autumn C. Marshall ◽

Ruth N. Henry ◽

...

Keyword(s):

Isometric Force ◽

Force Production ◽

Sprint Performance ◽

Peak Force ◽

Adolescent Males ◽

Height Velocity ◽

Beetroot Juice ◽

Repeated Sprint ◽

Group Time ◽

Isometric Force Production

The purpose of this study was to examine the effects of acute beetroot juice (BR) administration on repeated sprint performance and isometric force production in adolescent males. Twelve male adolescents (age, 16.8 ± 1.0 years; height, 178.8 ± 9.2 cm; mass, 74.8 ± 12.5 kg; peak height velocity, 2.53 ± 1.2 years) participated in this double-blind, placebo-controlled, crossover designed study. Participants consumed 2 × 70 mL of BR (∼12.9 mmol NO3−; Beet It Sport) or a nitrate-depleted placebo (PL) at 2.5 h prior to performing isometric mid-thigh pulls (IMTP) and 4 repeated 20-s Wingate sprints interspersed with 4 min of rest. Sprint data were analyzed by a 2 × 4 (group × time) repeated-measures ANOVA while a dependent t test was used to compare conditions for IMTP peak force. A significant main effect for time (p < 0.05) was observed for peak power (PP), average power (Pavg), and fatigue index (FI) across sprints. Compared with sprint 1, sprint 4 resulted in significant decreases in PP (p < 0.000; −16.6%) and Pavg (p = 0.000; −21.8%) and FI was significantly elevated (p < 0.000; 15.2%). No significant group × time interactions were observed between conditions for PP (p = 0.402), Pavg (p = 0.479), or FI (p = 0.37). IMTP peak force was significantly higher (p = 0.004; 13.9%) following BR consumption compared with PL. The repeated sprint protocol resulted in significant fatigue while BR did not influence sprint performance. However, it appears BR administration may improve peak force production in adolescent males.

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