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BEETROOT JUICE Effect on 10km Running Performance at Altitude. Arnold, J.T., Lewis-Jones, T., Oliver, S.J., Jones, A.M., Fudge, B., Macdonald, J.H.,. Tel; 07737834074 Email; josh.t.arnold@gmail.com. Introduction. Discovery Nitrate supplementation performance (Larsen et al., 2007)
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BEETROOT JUICEEffect on 10km Running Performance at Altitude Arnold, J.T., Lewis-Jones, T., Oliver, S.J., Jones, A.M., Fudge, B., Macdonald, J.H., Tel; 07737834074 Email; josh.t.arnold@gmail.com
Introduction Discovery Nitrate supplementation performance (Larsen et al., 2007) Two hypothesised mechanisms (Review: Jones, 2013) • Improved muscle contractile efficiency • Improved mitochondrial efficiency Rationale(Beet/Altitude link) Ergogenic effect of nitrate in hypoxic conditions (Lundberg et al. 2008)
Introduction This study aimed to investigate the effect of beetroot juice supplementation on 10km running performance at altitude.
Method Design Bloods samples drawn 2.5hrs post supplementation to assess plasma nitrate/nitrite Outcome Measures - Time to exhaustion (incremental test, speed and gradient protocol) - Maximal oxygen uptake - Steady state oxygen uptake (10min mountaineering specific inclined walk) - Time to complete 10km (self paced, blinded to speed and time)
Results 8 fold in plasma [NO2-] with beetroot ingestion (p = .000) Physiological 1.5% steady state SaO2 with beetroot ingestion (p = .000) Performance - 10km time trial Statistical differences??? Practically meaningful difference??? • a priory = • Δ-36 secs (Δ 1.1%) • VS. • obseved (HYPBR – HYPPL) • Δ -11 [-60 to 38] secs(Δ 0.4%) Significance determined by paired t-test ( n= 10).
Discussion Acute beetroot juice supplementation has no statistical or practically meaningful effect on exercise performance at altitude Possible Explanations Training Status • Highly trained athletes express higher resting plasma [NO3-] vs. sedentary (Jungersten et al. 1997) Beetroot Juice Dose or Individual response (Wylie et al. 2013) • Greater reductions in O2 uptake seen with higher concentrations of nitrate • 3 non-responder @ 4.2mmol NO3- , 2 non-responders @ 8.4mmol NO3- , 1 non-responders @ 16.8mmol NO3-.
Thank you for listening Jones, A. M. (2013). Dietary nitrate: The new magic bullet? Sports Science, 26(110), 1-5. Jungersten, L., Ambring, A., Wall, B., & Wennmalm, Å. (1997). Both physical fitness and acute exercise regulate nitric oxide formation in healthy humans. Journal of Applied Physiology, 82(3), 760-764. Larsen, F., Weitzberg, E., Lundberg, J., & Ekblom, B. (2007). Effects of dietary nitrate on oxygen cost during exercise.ActaPhysiologica, 191(1), 59-66. Lundberg, J. O., Weitzberg, E., & Gladwin, M. T. (2008). The nitrate–nitrite–nitric oxide pathway in physiology and therapeutics. Nature Reviews Drug Discovery, 7(2), 156-167. Wylie, L. J., Kelly, J., Bailey, S. J., Blackwell, J. R., Skiba, P. F., Winyard, P. G., Jones, A. M. (2013). Beetroot juice and exercise: Pharmacodynamic and dose-response relationships. Journal of Applied Physiology, Tel; 07737834074 Email; josh.t.arnold@gmail.com
Outline • General introduction & methods • Sub-study 1; Competitive Endurance Running • Sub-study 2; Mountaineering • General Discussion
Beetroot Juice Discovery 2007- 3 day sodium nitrate supp(Larsen et al., 2007) Finding – 5% decr oxygen cost Research Progression 2009- 3 day Beetroot Juice = 5% decr oxygen cost (Bailey et al., 2009) 2010- Acute dose (2.5hrs) (Vanhatalo et al., 2010) 2013- Two hypothesised mechanisms (Review: Jones, 2013) • Improved muscle contractile efficiency (Bailey et al., 2010) • Improved mitochondrial efficiency (Larsen et al., 2010) Rationale(Beet/Altitude link) • L-arginine-eNOS reduced vs. NO3--NO2--NO enhanced (Lundberg et al. 2008) High plasma [NO2-] in highland natives (Erzuum et al. 2007) & decr. fraction expired NO during ascent in lowlanders (Levett et al. 2011) Systematic review- hypoxic lit required (Hoon et al., 2013)
Methods (General) Double blind, repeated measures, cross over. Hypoxia + beetroot (HYPBR) vs. . Hypoxia + Placebo (HYPPL) 70ml concentrated beetroot juice @ 2.5hrs prior to exercise (James White Drinks) (HYPBR; ~7mmol NO3-) or (HYPPL; ~0.003mmol NO3-) Ten club level runners Mean (SD): Age, 37 (13)yrs, sea level VO2max 66 (7)mL.kg-1.min-1, 10km PB 36 (2)mins Analysis Statistcal- Paired t-test Applied- 95% CI vs. minimum Important difference Individual- Probability of true individual response (Hopkins 2002)
Study 1 Beetroot Juice: Effect on 10km Running Performance in Hypoxia Exercise Performance: Plasma [NO2-] correlated to exercise tolerance (Rassaf et al., 2007) 15% incr. running tolerance with 6 day supp(Lansley et al., 2011) Hopkins Performance Translation 2.7% incr. performance in TT (Lansley et al., 2011b) Hypothesis: Performance increase with beetroot supplementation as seen through a decrease in time to complete a 10km time trial.
Study 2 Beetroot Juice: Effect of on Physical Capability for High Altitude Mountaineering Mountaineering performance Teleoanticipatory approach; altered pacing RPE (brain) governs performance via Sao2 signals (Noakes & Marino 2007) Increased oxygenation with beetroot supplementation at altitude (Vanhataloet al. 2011, Masschelein et al. 2012) Hypothesis: Beetroot juice supplementation benefit mountaineering capability as seen through a reduction in rating of perceived exertion.
Study 1: Results • Applied settings • minimum important difference • Δ -36 secs (Δ 1.1%) • VS. • 10Km performance difference • (HYPBR – HYPPL) • Δ -11 [-60 to 38] secs or (Δ 0.4%) • Individual • Varied response: 3 likely incr. performance with beetroot, 1 likely decr. with beetroot. Figure 1:10km time trial performance at moderate altitude (2500 m) of trained athletes following acute beetroot or placebo supplementation Beetroot juice supplementation had no statistical or practical impact upon running performance HYPBR, beetroot supplementation. HYPPL, placebo supplementation. Significance determined by paired samples t-test (n = 10). Box and whisker = group response, with + = mean. Dots = individual response
Study 2: Results Figure 3: Differentiated RPE scores during steady state exercise at high altitude (4000m) following acute beetroot or placebo supplementation HYPBR, beetroot supplementation. HYPPL, placebo supplementation. Significance determined by paired samples t-test (n = 10). Box and whisker = group response, with + = mean. Dots = individual response Beetroot juice supplementation had no impact upon perceived exertion
General Discussion In contrast to the hypothesis acute beetroot juice supplementation showed no effect at group level. (see paper for Invidual response) Possible Explanations Training Status? Highly trained athletes sig. higher plasma [NO2-] vs. sedentary (Jungersten et al. 1997) Beetroot Juice Dose response? Reduced O2 uptake= 0% @ 4.2mmol NO3-(p=>0.05), 2% @ 8.4mmolNO3- (p=0.06), 3% @ 16.8mmol NO3- (p=>0.05) (Wylie et al. 2013) Variable response links to dose and potentially train status.(Wylie et al. 2013) 3 non-respon @ 4.2mmol NO3- , 2 non-respon @ 8.4mmol NO3- , 1 non- respon @ 16.8mmol NO3-. (Wylie et al. 2013)
Mechanistic Notes Decrease in aerobic with no anaerobic compensation [BLa marker (Bailey et al. 2009)] Two possible mechanisms • Incr. muscle contractile efficiency. Lower ATP cost for same force. (Some evidence seen in: Vanhatalo et al. 2011) - NO slowsCa2-ATPase activity (regulator of ATP turnover) (Evangelista et al., 2010) and therefor reduces [ADP] and [Pi] production (stimuli of oxidative phosphorylation (Mahler, 1985)). 2. Incr. mitochondrial efficiency. Lower VO2 for the same ATP resynthesis(Some evidence seen in: Larsen et al. 2011) - Decr. Proton leakage across and therefore better P/O ratio (amount of ATP produced per oxygen used). Increase P/O correlated with reduce VO2(Larsen et al. 2011) Other High plasma [NO2-] in highland natives (Erzuum et al. 2007) & decr. fraction expired NO during ascent in lowlanders (Levett et al. 2011)
Dose Notes Hoon et al., 2013 • 6 of 8 studies using chronic dose found an effect • 11 of 12 studies using chronic found an effect
Performance Notes Hypoxic Specific • 20% incr. in knee extention TTE in hypoxia (Vanhatalo et al., 2010) • 36% reduce in TTE (Masschelein et al. 2012) • TT performance incr. with acute dose @ altitude (Muggeridge et al. 2013)
Training Status Notes Hoon et al., 2013 • All 11 trials in untrained subject showed positive effect • Only 7 of 10 showed effect in trained
Study 1: Results (continued..) Figure 2:Measured parameters during incremental exercise at high altitude (4000 m) of trained athletes following acute beetroot or placebo supplementation. HYPBR, beetroot supplementation. HYPPL, placebo supplementation. Significance determined by paired samples t-test (n = 10). Box and whisker = group response, with + = mean. Dots = individual response
Study 2: Results (continued) Figure 4: Measured parameters during mountaineering specific steady state exercise at high altitude (4000 m) following acute beetroot or placebo supplementation. HYPBR, beetroot supplementation. HYPPL, placebo supplementation. Significance determined by paired samples t-test (n = 10). Box and whisker = group response, with + = mean. Dots = individual response