View source for Beetroot and Running Performance

There have been a number of studies recently that show [http://en.wikipedia.org/wiki/Beetroot Beetroot] (beets in the US) improve exercise performance including running. Beetroot juice has no side effects, takes effect within an hour, and remains active for days. However, don't clean your teeth or use a mouthwash immediately before consuming the beetroot. 
=Details=
Studies<ref name="Larsen FJ"/><ref name="Ferreira"/><ref name="Bailey"/><ref name="Time"/><ref name="Bailey2"/>indicate that beetroot juice has a number of benefits
* Improved [[Running Economy]], which is reduction in the oxygen required across a range of efforts. This is without any increase in blood [[Lactate|lactate]] that would indicate nonoxidative energy production.
* Increased time to exhaustion in maximal exercise with VO<sub>2</sub>max unchanged.
* Reduced resting blood pressure.
=Effective Dose=
It's been suggested that the minimum effective dose is 5 mmol of Nitrate (NO<sub>3</sub>) <ref name="Gallardo-2018"/>. (For Nitrate, 1g=16mmol.) However, nitrate content of beetroot is highly variable<ref name="WrussWaldenberger2015"/>, with whole beetroots and beetroot powder varying by a factor of ten between varieties. The variation between beetroot juices was even larger, varying by x250. 
=Sources=
There are lots of products based on beets, and it's hard to work out what's going to be the best for convenience and cost. 
==Beetroot==
The obvious source is beetroot as a vegetable. An analysis found that beetroot averages ~1g/Kg fresh beetroot<ref name="WrussWaldenberger2015"/>, which is ~15 mmol/Kg. Therefore, you'd need to eat about 300g/11oz of beetroot. However, different varieties varied between ~280mg/Kg and 2,300mg/Kg. 
==Beetroot Powder==
An analysis of four powders found the nitrate content varying between 0.125 mmol/g and 0.87 mmol/g, meaning you'd need to take between 6g and 40g of beetroot powder, a huge variation<ref name="WrussWaldenberger2015"/>. Another analysis of 6 powders found the variation to be from 0.10 to 0.256 mmol/g, requiring between 46g and 20g of powder for an effective dose. This makes beetroot powder quite expensive; I calculated the price between $2.50 and $6 per dose. Here's my rough estimate of the cost per 5mmol dose based on Amazon pricing. '''Important: both the price and nitrate concentration could easily vary for the same brand, so use this data with caution. None of the available beetroot sources specifies the nitrate concentration''''''.''' 
{| class="wikitable" style="margin-left: auto; margin-right: auto; border: none;"
! Brand
! g/serving
! mmol/serving
! mmol/g
! g/dose
! unit price
! Grams/unit
! per gram
! cost/dose
|-
| redibeets
| 4
| 0.43
| 0.1075
| 47
|  $          32 
| 250
| 0.128
|  $       5.95 
|-
| superbeets
| 5
| 1.03
| 0.2060
| 24
|  $          35 
| 153
| 0.229
|  $       5.55 
|-
| endurance beets
| 11
| 1.08
| 0.0982
| 51
|  $          17 
| 220
| 0.077
|  $       3.94 
|-
| beetboost
| 11
| 1.78
| 0.1618
| 31
|  $          38 
| 200
| 0.190
|  $       5.87 
|-
| beetelite
| 10
| 2.16
| 0.2160
| 23
|  $          35 
| 200
| 0.175
|  $       4.05 
|-
| pureclean powder
| 10
| 2.56
| 0.2560
| 20
|  $          39 
| 300
| 0.130
|  $       2.54 
|}
Another alternative would be "bulk supplements beet powder", which is much cheaper per gram, but with unknown nitrate concentration. 
=Beetroot Juice=
The amount of nitrate in beetroot juice also varies widely, and I calculated the rough cost/dose. I was surprised to find that beetroot juice was far cheaper than the powders. '''Important: both the price and nitrate concentration could easily vary for the same brand, so use this data with caution. None of the available beetroot sources specifies the nitrate concentration''''''.'''
{| class="wikitable" style="margin-left: auto; margin-right: auto; border: none;"
! Brand
! ml/serving
! mmol/serving
! mmol/ml
! ml/dose
! unit price
! ml/unit
! per ml
! cost/dose
|-
| Lakewood juice
| 500
| 18.77
| 0.0375
| 133
|  $             6 
| 946
| 0.007
|  $       0.89 
|-
| Beet it juice
| 500
| 7.55
| 0.0151
| 331
|  $          12 
| 1000
| 0.012
|  $       3.97 
|}
{{BuyAmazon|AZID=B00IB7DSCG|AZN=Lakewood Organic PURE Beet Juice }}
=Implications for Runners=
Beetroot supplementation a way of reducing the energy cost of exercise (improved [[Running Economy]]). This reduction in energy cost is especially important for marathon runners, where the [[Glycogen]] stores are a limiting factor in performance. Runners focused on shorter distances would benefit from the increased time to exhaustion at high intensity. 
=Period of Effect=
The changes from beetroot take effect in about 30 minutes, peak after 90 minutes, stay elevated for 6 hours<ref name="Spitting"/> and remain effective for at least 15 days<ref name="Time"/> Taking beetroot juice daily will build up the effect over a 3-4 days then plateau. 
=Active Component=
One study<ref name="Ferreira"/> removed the Nitrates from the beetroot juice and found that the effects also disappeared, indicating that the Nitrates are the active ingredient.  The Nitrates (NO<sub>3</sub>) in beetroot juice are converted to Nitrites (NO<sub>2</sub>), and it is the nitrite that has the effect. Using an antibacterial mouthwash before taking beetroot juice prevents the nitrate being turned into nitrite<ref name="Mouthwash"/>.
=Side Effects=
The only documented side effects of beetroot (other than the taste) is [http://en.wikipedia.org/wiki/Beeturia Beeturia], which is pink or red colored urine. While this effect may be disconcerting, it is harmless and effects only about 10-14% of the healthy population. However, you are far more likely to have Beeturia if you are anemic, so have your blood checked if you get the symptoms, just in case. There are many other reported side effects of beetroot, including paralysis of vocal cords, have been reported on the internet, but I've found no documented cases and this appears to be urban legend<ref name="Livestrong"/>. 
=The spinach alternative?=
Another source of nitrate is spinach, which may be a substitute for those that don't like beets. Around 100-300g of spinach are claimed to have similar results to the equivalent weight of beets<ref name="Larsen-2010"/><ref name="Larsen-2006"/><ref name="spinach"/>. Canned beets contain 170-290 mg/100g nitrates<ref name="LeeShallenberger1971"/>, and the spinach petioles (stalks) can contain a similar 10-260 mg/100g, but the spinach leaves only contain 4-12 mg/100g<ref name="YosefiTabaraki2010"/>. Also, note that cooking reduces the nitrate levels in spinach<ref name="Phillips1968"/>. Some studies<ref name="Larsen-2011"/> used Sodium Nitrate directly, at a level which may be equivalent to about 300g of spinach. Eating 300g (10oz) is about 7 cups of spinach, which would take some dedication to consume.
=Alternatives =
Another approach is to take the amino acids Citrulline or Arginine to boost nitric oxide. I'd recommend reading [https://examine.com/supplements/citrulline/] and [https://examine.com/supplements/arginine/] for a review of the research. 
=References=
<references>
<ref name="WrussWaldenberger2015">Jürgen Wruss, Gundula Waldenberger, Stefan Huemer, Pinar Uygun, Peter Lanzerstorfer, Ulrike Müller, Otmar Höglinger, Julian Weghuber, Compositional characteristics of commercial beetroot products and beetroot juice prepared from seven beetroot varieties grown in Upper Austria, Journal of Food Composition and Analysis, volume 42, 2015, pages 46–55, ISSN [http://www.worldcat.org/issn/08891575 08891575], doi [http://dx.doi.org/10.1016/j.jfca.2015.03.005 10.1016/j.jfca.2015.03.005]</ref>
<ref name="Gallardo-2018">EJ. Gallardo, AR. Coggan, What's in Your Beet Juice? Nitrate and Nitrite Content of Beet Juice Products Marketed to Athletes., Int J Sport Nutr Exerc Metab, pages 1-17, Oct 2018, doi [http://dx.doi.org/10.1123/ijsnem.2018-0223 10.1123/ijsnem.2018-0223], PMID [http://www.ncbi.nlm.nih.gov/pubmed/30299195 30299195]</ref>
<ref name="Larsen FJ"> Dietary nitrate reduces maximal oxygen consumption while maintaining work performance in maximal exercise. http://www.ncbi.nlm.nih.gov/pubmed/19913611 </ref>
<ref name="Ferreira"> A toast to health and performance! Beetroot juice lowers blood pressure and the O2 cost of exercise http://jap.physiology.org/content/110/3/585.extract</ref>
<ref name="Bailey"> Dietary nitrate supplementation enhances muscle contractile efficiency during knee-extensor exercise in humans http://jap.physiology.org/content/109/1/135.short</ref>
<ref name="Time">Acute and chronic effects of dietary nitrate supplementation on blood pressure and the physiological responses to moderate-intensity and incremental exercise  http://ajpregu.physiology.org/content/299/4/R1121.short</ref>
<ref name="Bailey2">Dietary nitrate supplementation reduces the O2 cost of low-intensity exercise and enhances tolerance to high-intensity exercise in humans  http://jap.physiology.org/content/107/4/1144.full </ref>
<ref name="Mouthwash">The increase in plasma nitrite after a dietary nitrate load is markedly attenuated by an antibacterial mouthwash http://www.ncbi.nlm.nih.gov/pubmed/18793740?dopt=Abstract</ref>
<ref name="Spitting">Acute Blood Pressure Lowering, Vasoprotective, and Antiplatelet Properties of Dietary Nitrate via Bioconversion to Nitrite http://hyper.ahajournals.org/cgi/content/full/51/3/784?ijkey=5ec725973d624beded6be2d3792e3ed9a10b09d2</ref>
<ref name="Livestrong">What Are the Benefits of Drinking Beet Juice? http://www.livestrong.com/article/343584-what-are-the-benefits-of-drinking-beet-juice/</ref>
<ref name="spinach">Nitrate from spinach boosts muscle mitochondria function http://ihealthbulletin.com/blog/2011/02/02/nitrate-spinach-boosts-muscle-mitochondria/</ref>
<ref name="Larsen-2006"> FJ. Larsen, B. Ekblom, K. Sahlin, JO. Lundberg, E. Weitzberg, Effects of dietary nitrate on blood pressure in healthy volunteers., N Engl J Med, volume 355, issue 26, pages 2792-3, Dec 2006, doi [http://dx.doi.org/10.1056/NEJMc062800 10.1056/NEJMc062800], PMID [http://www.ncbi.nlm.nih.gov/pubmed/17192551 17192551]</ref>
<ref name="LeeShallenberger1971">C. Y. Lee, R. S. Shallenberger, D. L. Downing, G. S. Stoewsand, N. M. Peck, Nitrate and nitrite nitrogen in fresh, stored and processed table beets and spinach from different levels of field nitrogen fertilisation, Journal of the Science of Food and Agriculture, volume 22, issue 2, 1971, pages 90–92, ISSN [http://www.worldcat.org/issn/00225142 00225142], doi [http://dx.doi.org/10.1002/jsfa.2740220212 10.1002/jsfa.2740220212]</ref>
<ref name="Phillips1968">William E. J. Phillips, Changes in the nitrate and nitrite contents of fresh and processed spinach during storage, Journal of Agricultural and Food Chemistry, volume 16, issue 1, 1968, pages 88–91, ISSN [http://www.worldcat.org/issn/0021-8561 0021-8561], doi [http://dx.doi.org/10.1021/jf60155a012 10.1021/jf60155a012]</ref>
<ref name="YosefiTabaraki2010">Z. Yosefi, R. Tabaraki, H. A. Asadi Gharneh, A. A. Mehrabi, Variation in Antioxidant Activity, Total Phenolics, and Nitrate in Spinach, International Journal of Vegetable Science, volume 16, issue 3, 2010, pages 233–242, ISSN [http://www.worldcat.org/issn/1931-5260 1931-5260], doi [http://dx.doi.org/10.1080/19315260903577278 10.1080/19315260903577278]</ref>
<ref name="Larsen-2010"> FJ. Larsen, E. Weitzberg, JO. Lundberg, B. Ekblom, Dietary nitrate reduces maximal oxygen consumption while maintaining work performance in maximal exercise., Free Radic Biol Med, volume 48, issue 2, pages 342-7, Jan 2010, doi [http://dx.doi.org/10.1016/j.freeradbiomed.2009.11.006 10.1016/j.freeradbiomed.2009.11.006], PMID [http://www.ncbi.nlm.nih.gov/pubmed/19913611 19913611]</ref>
<ref name="Larsen-2011"> FJ. Larsen, TA. Schiffer, S. Borniquel, K. Sahlin, B. Ekblom, JO. Lundberg, E. Weitzberg, Dietary inorganic nitrate improves mitochondrial efficiency in humans., Cell Metab, volume 13, issue 2, pages 149-59, Feb 2011, doi [http://dx.doi.org/10.1016/j.cmet.2011.01.004 10.1016/j.cmet.2011.01.004], PMID [http://www.ncbi.nlm.nih.gov/pubmed/21284982 21284982]</ref>
</references>
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